diff --git a/brouter-core/src/main/java/btools/router/RoutingEngine.java b/brouter-core/src/main/java/btools/router/RoutingEngine.java
index 105ed0952..4d706e3c0 100644
--- a/brouter-core/src/main/java/btools/router/RoutingEngine.java
+++ b/brouter-core/src/main/java/btools/router/RoutingEngine.java
@@ -20,6 +20,7 @@
 import btools.mapaccess.OsmLinkHolder;
 import btools.mapaccess.OsmNode;
 import btools.mapaccess.OsmNodePairSet;
+import btools.mapaccess.OsmPos;
 import btools.util.CompactLongMap;
 import btools.util.SortedHeap;
 import btools.util.StackSampler;
@@ -907,11 +908,12 @@ private void recalcTrack(OsmTrack t) {
         if (ele_last != Short.MIN_VALUE) {
           ehb = ehb + (ele_last - ele) * eleFactor;
         }
+        double filter = elevationFilter(n);
         if (ehb > 0) {
           ascend += ehb;
           ehb = 0;
-        } else if (ehb < -10) {
-          ehb = -10;
+        } else if (ehb < filter) {
+          ehb = filter;
         }
       }
 
@@ -948,6 +950,21 @@ private void recalcTrack(OsmTrack t) {
     logInfo("filtered ascend = " + t.ascend);
   }
 
+  /**
+   * find the elevation type for position
+   * to determine the filter value
+   *
+   * @param n  the point
+   * @return  the filter value for 1sec / 3sec elevation source
+   */
+  double elevationFilter(OsmPos n) {
+    if (nodesCache != null) {
+      int r = nodesCache.getElevationType(n.getILon(), n.getILat());
+      if (r == 1) return -5.;
+    }
+    return -10.;
+  }
+
   // geometric position matching finding the nearest routable way-section
   private void matchWaypointsToNodes(List<MatchedWaypoint> unmatchedWaypoints) {
     resetCache(false);
diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/ConvertLidarTile.java b/brouter-map-creator/src/main/java/btools/mapcreator/ConvertLidarTile.java
deleted file mode 100644
index 2a00e96be..000000000
--- a/brouter-map-creator/src/main/java/btools/mapcreator/ConvertLidarTile.java
+++ /dev/null
@@ -1,250 +0,0 @@
-package btools.mapcreator;
-
-import java.io.BufferedInputStream;
-import java.io.BufferedOutputStream;
-import java.io.DataInputStream;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.util.Arrays;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipInputStream;
-
-public class ConvertLidarTile {
-  private static int NROWS;
-  private static int NCOLS;
-
-  public static final short NODATA2 = -32767; // hgt-formats nodata
-  public static final short NODATA = Short.MIN_VALUE;
-
-  private static final String HGT_FILE_EXT = ".hgt";
-  private static final int HGT_BORDER_OVERLAP = 1;
-  private static final int HGT_3ASEC_ROWS = 1201; // 3 arc second resolution (90m)
-  private static final int HGT_3ASEC_FILE_SIZE = HGT_3ASEC_ROWS * HGT_3ASEC_ROWS * Short.BYTES;
-  private static final int HGT_1ASEC_ROWS = 3601; // 1 arc second resolution (30m)
-
-  static short[] imagePixels;
-
-  private static void readHgtZip(String filename, int rowOffset, int colOffset) throws Exception {
-    ZipInputStream zis = new ZipInputStream(new BufferedInputStream(new FileInputStream(filename)));
-    try {
-      for (; ; ) {
-        ZipEntry ze = zis.getNextEntry();
-        if (ze == null) break;
-        if (ze.getName().toLowerCase().endsWith(HGT_FILE_EXT)) {
-          readHgtFromStream(zis, rowOffset, colOffset, HGT_3ASEC_ROWS);
-          return;
-        }
-      }
-    } finally {
-      zis.close();
-    }
-  }
-
-  private static void readHgtFromStream(InputStream is, int rowOffset, int colOffset, int rowLength)
-    throws Exception {
-    DataInputStream dis = new DataInputStream(new BufferedInputStream(is));
-    for (int ir = 0; ir < rowLength; ir++) {
-      int row = rowOffset + ir;
-
-      for (int ic = 0; ic < rowLength; ic++) {
-        int col = colOffset + ic;
-
-        int i1 = dis.read(); // msb first!
-        int i0 = dis.read();
-
-        if (i0 == -1 || i1 == -1)
-          throw new RuntimeException("unexpected end of file reading hgt entry!");
-
-        short val = (short) ((i1 << 8) | i0);
-
-        if (val == NODATA2) {
-          val = NODATA;
-        }
-
-        setPixel(row, col, val);
-      }
-    }
-  }
-
-  private static void setPixel(int row, int col, short val) {
-    if (row >= 0 && row < NROWS && col >= 0 && col < NCOLS) {
-      imagePixels[row * NCOLS + col] = val;
-    }
-  }
-
-  private static short getPixel(int row, int col) {
-    if (row >= 0 && row < NROWS && col >= 0 && col < NCOLS) {
-      return imagePixels[row * NCOLS + col];
-    }
-    return NODATA;
-  }
-
-
-  public static void doConvert(String inputDir, int lonDegreeStart, int latDegreeStart, String outputFile) throws Exception {
-    int extraBorder = 0;
-
-    NROWS = 5 * 1200 + 1 + 2 * extraBorder;
-    NCOLS = 5 * 1200 + 1 + 2 * extraBorder;
-
-    imagePixels = new short[NROWS * NCOLS]; // 650 MB !
-
-    // prefill as NODATA
-    for (int row = 0; row < NROWS; row++) {
-      for (int col = 0; col < NCOLS; col++) {
-        imagePixels[row * NCOLS + col] = NODATA;
-      }
-    }
-
-    for (int latIdx = -1; latIdx <= 5; latIdx++) {
-      int latDegree = latDegreeStart + latIdx;
-      int rowOffset = extraBorder + (4 - latIdx) * 1200;
-
-      for (int lonIdx = -1; lonIdx <= 5; lonIdx++) {
-        int lonDegree = lonDegreeStart + lonIdx;
-        int colOffset = extraBorder + lonIdx * 1200;
-
-        String filename = inputDir + "/" + formatLat(latDegree) + formatLon(lonDegree) + ".zip";
-        File f = new File(filename);
-        if (f.exists() && f.length() > 0) {
-          System.out.println("exist: " + filename);
-          readHgtZip(filename, rowOffset, colOffset);
-        } else {
-          System.out.println("none : " + filename);
-        }
-      }
-    }
-
-    boolean halfCol5 = false; // no halfcol tiles in lidar data (?)
-
-
-    SrtmRaster raster = new SrtmRaster();
-    raster.nrows = NROWS;
-    raster.ncols = NCOLS;
-    raster.halfcol = halfCol5;
-    raster.noDataValue = NODATA;
-    raster.cellsize = 1 / 1200.;
-    raster.xllcorner = lonDegreeStart - (0.5 + extraBorder) * raster.cellsize;
-    raster.yllcorner = latDegreeStart - (0.5 + extraBorder) * raster.cellsize;
-    raster.eval_array = imagePixels;
-
-    // encode the raster
-    OutputStream os = new BufferedOutputStream(new FileOutputStream(outputFile));
-    new RasterCoder().encodeRaster(raster, os);
-    os.close();
-
-    // decode the raster
-    InputStream is = new BufferedInputStream(new FileInputStream(outputFile));
-    SrtmRaster raster2 = new RasterCoder().decodeRaster(is);
-    is.close();
-
-    short[] pix2 = raster2.eval_array;
-    if (pix2.length != imagePixels.length)
-      throw new RuntimeException("length mismatch!");
-
-    // compare decoding result
-    for (int row = 0; row < NROWS; row++) {
-      int colstep = halfCol5 ? 2 : 1;
-      for (int col = 0; col < NCOLS; col += colstep) {
-        int idx = row * NCOLS + col;
-        short p2 = pix2[idx];
-        if (p2 != imagePixels[idx]) {
-          throw new RuntimeException("content mismatch: p2=" + p2 + " p1=" + imagePixels[idx]);
-        }
-      }
-    }
-  }
-
-  private static String formatLon(int lon) {
-    if (lon >= 180)
-      lon -= 180; // TODO: w180 oder E180 ?
-
-    String s = "E";
-    if (lon < 0) {
-      lon = -lon;
-      s = "W";
-    }
-    String n = "000" + lon;
-    return s + n.substring(n.length() - 3);
-  }
-
-  private static String formatLat(int lat) {
-    String s = "N";
-    if (lat < 0) {
-      lat = -lat;
-      s = "S";
-    }
-    String n = "00" + lat;
-    return s + n.substring(n.length() - 2);
-  }
-
-  public static void main(String[] args) throws Exception {
-    String filename90 = args[0];
-    String filename30 = filename90.substring(0, filename90.length() - 3) + "bef";
-
-    int srtmLonIdx = Integer.parseInt(filename90.substring(5, 7).toLowerCase());
-    int srtmLatIdx = Integer.parseInt(filename90.substring(8, 10).toLowerCase());
-
-    int ilon_base = (srtmLonIdx - 1) * 5 - 180;
-    int ilat_base = 150 - srtmLatIdx * 5 - 90;
-
-    doConvert(args[1], ilon_base, ilat_base, filename30);
-  }
-
-  public SrtmRaster getRaster(File f, double lon, double lat) throws Exception {
-    long fileSize;
-    InputStream inputStream;
-
-    if (f.getName().toLowerCase().endsWith(".zip")) {
-      ZipInputStream zis = new ZipInputStream(new BufferedInputStream(new FileInputStream(f)));
-      for (; ; ) {
-        ZipEntry ze = zis.getNextEntry();
-        if (ze == null) {
-          throw new FileNotFoundException(f.getName() + " doesn't contain a " + HGT_FILE_EXT + " file.");
-        }
-        if (ze.getName().toLowerCase().endsWith(HGT_FILE_EXT)) {
-          fileSize = ze.getSize();
-          inputStream = zis;
-          break;
-        }
-      }
-    } else {
-      fileSize = f.length();
-      inputStream = new FileInputStream(f);
-    }
-
-    int rowLength;
-    if (fileSize > HGT_3ASEC_FILE_SIZE) {
-      rowLength = HGT_1ASEC_ROWS;
-    } else {
-      rowLength = HGT_3ASEC_ROWS;
-    }
-
-    // stay at 1 deg * 1 deg raster
-    NROWS = rowLength;
-    NCOLS = rowLength;
-
-    imagePixels = new short[NROWS * NCOLS];
-
-    // prefill as NODATA
-    Arrays.fill(imagePixels, NODATA);
-    readHgtFromStream(inputStream, 0, 0, rowLength);
-    inputStream.close();
-
-    SrtmRaster raster = new SrtmRaster();
-    raster.nrows = NROWS;
-    raster.ncols = NCOLS;
-    raster.halfcol = false; // assume full resolution
-    raster.noDataValue = NODATA;
-    raster.cellsize = 1. / (double) (rowLength - HGT_BORDER_OVERLAP);
-    raster.xllcorner = (int) (lon < 0 ? lon - 1 : lon); //onDegreeStart - raster.cellsize;
-    raster.yllcorner = (int) (lat < 0 ? lat - 1 : lat); //latDegreeStart - raster.cellsize;
-    raster.eval_array = imagePixels;
-
-    return raster;
-  }
-
-}
diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/ConvertSrtmTile.java b/brouter-map-creator/src/main/java/btools/mapcreator/ConvertSrtmTile.java
deleted file mode 100644
index e18c66451..000000000
--- a/brouter-map-creator/src/main/java/btools/mapcreator/ConvertSrtmTile.java
+++ /dev/null
@@ -1,260 +0,0 @@
-package btools.mapcreator;
-
-import java.io.*;
-import java.util.zip.*;
-
-public class ConvertSrtmTile {
-  public static int NROWS;
-  public static int NCOLS;
-
-  public static final short SKIPDATA = -32766; // >50 degree skipped pixel
-  public static final short NODATA2 = -32767; // bil-formats nodata
-  public static final short NODATA = Short.MIN_VALUE;
-
-  static short[] imagePixels;
-
-  public static int[] diffs = new int[100];
-
-  private static void readBilZip(String filename, int rowOffset, int colOffset, boolean halfCols) throws Exception {
-    ZipInputStream zis = new ZipInputStream(new BufferedInputStream(new FileInputStream(filename)));
-    try {
-      for (; ; ) {
-        ZipEntry ze = zis.getNextEntry();
-        if (ze.getName().endsWith(".bil")) {
-          readBilFromStream(zis, rowOffset, colOffset, halfCols);
-          return;
-        }
-      }
-    } finally {
-      zis.close();
-    }
-  }
-
-  private static void readBilFromStream(InputStream is, int rowOffset, int colOffset, boolean halfCols)
-    throws Exception {
-    DataInputStream dis = new DataInputStream(new BufferedInputStream(is));
-    for (int ir = 0; ir < 3601; ir++) {
-      int row = rowOffset + ir;
-
-      for (int ic = 0; ic < 3601; ic++) {
-        int col = colOffset + ic;
-
-        if ((ic % 2) == 1 && halfCols) {
-          if (getPixel(row, col) == NODATA) {
-            setPixel(row, col, SKIPDATA);
-          }
-          continue;
-        }
-
-        int i0 = dis.read();
-        int i1 = dis.read();
-
-        if (i0 == -1 || i1 == -1)
-          throw new RuntimeException("unexcepted end of file reading bil entry!");
-
-        short val = (short) ((i1 << 8) | i0);
-
-        if (val == NODATA2) {
-          val = NODATA;
-        }
-
-        setPixel(row, col, val);
-      }
-    }
-  }
-
-
-  private static void setPixel(int row, int col, short val) {
-    if (row >= 0 && row < NROWS && col >= 0 && col < NCOLS) {
-      imagePixels[row * NCOLS + col] = val;
-    }
-  }
-
-  private static short getPixel(int row, int col) {
-    if (row >= 0 && row < NROWS && col >= 0 && col < NCOLS) {
-      return imagePixels[row * NCOLS + col];
-    }
-    return NODATA;
-  }
-
-
-  public static void doConvert(String inputDir, String v1Dir, int lonDegreeStart, int latDegreeStart, String outputFile, SrtmRaster raster90) throws Exception {
-    int extraBorder = 10;
-    int datacells = 0;
-    int mismatches = 0;
-
-    NROWS = 5 * 3600 + 1 + 2 * extraBorder;
-    NCOLS = 5 * 3600 + 1 + 2 * extraBorder;
-
-    imagePixels = new short[NROWS * NCOLS]; // 650 MB !
-
-    // prefill as NODATA
-    for (int row = 0; row < NROWS; row++) {
-      for (int col = 0; col < NCOLS; col++) {
-        imagePixels[row * NCOLS + col] = NODATA;
-      }
-    }
-
-    for (int latIdx = -1; latIdx <= 5; latIdx++) {
-      int latDegree = latDegreeStart + latIdx;
-      int rowOffset = extraBorder + (4 - latIdx) * 3600;
-
-      for (int lonIdx = -1; lonIdx <= 5; lonIdx++) {
-        int lonDegree = lonDegreeStart + lonIdx;
-        int colOffset = extraBorder + lonIdx * 3600;
-
-        String filename = inputDir + "/" + formatLat(latDegree) + "_" + formatLon(lonDegree) + "_1arc_v3_bil.zip";
-        File f = new File(filename);
-        if (f.exists() && f.length() > 0) {
-          System.out.println("exist: " + filename);
-          boolean halfCol = latDegree >= 50 || latDegree < -50;
-          readBilZip(filename, rowOffset, colOffset, halfCol);
-        } else {
-          System.out.println("none : " + filename);
-        }
-      }
-    }
-
-    boolean halfCol5 = latDegreeStart >= 50 || latDegreeStart < -50;
-
-    for (int row90 = 0; row90 < 6001; row90++) {
-      int crow = 3 * row90 + extraBorder; // center row of 3x3
-      for (int col90 = 0; col90 < 6001; col90++) {
-        int ccol = 3 * col90 + extraBorder; // center col of 3x3
-
-        // evaluate 3x3 area
-        if (raster90 != null && (!halfCol5 || (col90 % 2) == 0)) {
-          short v90 = raster90.eval_array[row90 * 6001 + col90];
-
-          int sum = 0;
-          int nodatas = 0;
-          int datas = 0;
-          int colstep = halfCol5 ? 2 : 1;
-          for (int row = crow - 1; row <= crow + 1; row++) {
-            for (int col = ccol - colstep; col <= ccol + colstep; col += colstep) {
-              short v30 = imagePixels[row * NCOLS + col];
-              if (v30 == NODATA) {
-                nodatas++;
-              } else if (v30 != SKIPDATA) {
-                sum += v30;
-                datas++;
-              }
-            }
-          }
-          boolean doReplace = nodatas > 0 || v90 == NODATA || datas < 7;
-          if (!doReplace) {
-            datacells++;
-            int diff = sum - datas * v90;
-            if (diff < -4 || diff > 4) {
-              doReplace = true;
-              mismatches++;
-            }
-
-            if (diff > -50 && diff < 50 && (row90 % 1200) != 0 && (col90 % 1200) != 0) {
-              diffs[diff + 50]++;
-            }
-          }
-          if (doReplace) {
-            for (int row = crow - 1; row <= crow + 1; row++) {
-              for (int col = ccol - colstep; col <= ccol + colstep; col += colstep) {
-                imagePixels[row * NCOLS + col] = v90;
-              }
-            }
-          }
-        }
-      }
-    }
-
-    SrtmRaster raster = new SrtmRaster();
-    raster.nrows = NROWS;
-    raster.ncols = NCOLS;
-    raster.halfcol = halfCol5;
-    raster.noDataValue = NODATA;
-    raster.cellsize = 1 / 3600.;
-    raster.xllcorner = lonDegreeStart - (0.5 + extraBorder) * raster.cellsize;
-    raster.yllcorner = latDegreeStart - (0.5 + extraBorder) * raster.cellsize;
-    raster.eval_array = imagePixels;
-
-    // encode the raster
-    OutputStream os = new BufferedOutputStream(new FileOutputStream(outputFile));
-    new RasterCoder().encodeRaster(raster, os);
-    os.close();
-
-    // decode the raster
-    InputStream is = new BufferedInputStream(new FileInputStream(outputFile));
-    SrtmRaster raster2 = new RasterCoder().decodeRaster(is);
-    is.close();
-
-    short[] pix2 = raster2.eval_array;
-    if (pix2.length != imagePixels.length)
-      throw new RuntimeException("length mismatch!");
-
-    // compare decoding result
-    for (int row = 0; row < NROWS; row++) {
-      int colstep = halfCol5 ? 2 : 1;
-      for (int col = 0; col < NCOLS; col += colstep) {
-        int idx = row * NCOLS + col;
-        if (imagePixels[idx] == SKIPDATA) {
-          continue;
-        }
-        short p2 = pix2[idx];
-        if (p2 > SKIPDATA) {
-          p2 /= 2;
-        }
-        if (p2 != imagePixels[idx]) {
-          throw new RuntimeException("content mismatch!");
-        }
-      }
-    }
-
-    for (int i = 1; i < 100; i++) System.out.println("diff[" + (i - 50) + "] = " + diffs[i]);
-    System.out.println("datacells=" + datacells + " mismatch%=" + (100. * mismatches) / datacells);
-    btools.util.MixCoderDataOutputStream.stats();
-    // test( raster );
-    // raster.calcWeights( 50. );
-    // test( raster );
-    // 39828330 &lon=3115280&layer=OpenStreetMap
-  }
-
-  private static void test(SrtmRaster raster) {
-    int lat0 = 39828330;
-    int lon0 = 3115280;
-
-    for (int iy = -9; iy <= 9; iy++) {
-      StringBuilder sb = new StringBuilder();
-      for (int ix = -9; ix <= 9; ix++) {
-        int lat = lat0 + 90000000 - 100 * iy;
-        int lon = lon0 + 180000000 + 100 * ix;
-        int ival = (int) (raster.getElevation(lon, lat) / 4.);
-        String sval = "     " + ival;
-        sb.append(sval.substring(sval.length() - 4));
-      }
-      System.out.println(sb);
-      System.out.println();
-    }
-  }
-
-  private static String formatLon(int lon) {
-    if (lon >= 180)
-      lon -= 180; // TODO: w180 oder E180 ?
-
-    String s = "e";
-    if (lon < 0) {
-      lon = -lon;
-      s = "w";
-    }
-    String n = "000" + lon;
-    return s + n.substring(n.length() - 3);
-  }
-
-  private static String formatLat(int lat) {
-    String s = "n";
-    if (lat < 0) {
-      lat = -lat;
-      s = "s";
-    }
-    String n = "00" + lat;
-    return s + n.substring(n.length() - 2);
-  }
-
-}
diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/ConvertUrlList.java b/brouter-map-creator/src/main/java/btools/mapcreator/ConvertUrlList.java
deleted file mode 100644
index ab5b8dbef..000000000
--- a/brouter-map-creator/src/main/java/btools/mapcreator/ConvertUrlList.java
+++ /dev/null
@@ -1,53 +0,0 @@
-package btools.mapcreator;
-
-import java.io.BufferedReader;
-import java.io.File;
-import java.io.FileReader;
-
-public class ConvertUrlList {
-  public static final short NODATA = -32767;
-
-  public static void main(String[] args) throws Exception {
-    BufferedReader br = new BufferedReader(new FileReader(args[0]));
-
-    for (; ; ) {
-      String line = br.readLine();
-      if (line == null) {
-        break;
-      }
-      int idx1 = line.indexOf("srtm_");
-      if (idx1 < 0) {
-        continue;
-      }
-
-      String filename90 = line.substring(idx1);
-      String filename30 = filename90.substring(0, filename90.length() - 3) + "bef";
-
-      if (new File(filename30).exists()) {
-        continue;
-      }
-
-      // int srtmLonIdx = (ilon+5000000)/5000000; -> ilon = (srtmLonIdx-1)*5
-      // int srtmLatIdx = (154999999-ilat)/5000000; -> ilat = 155 - srtmLatIdx*5
-
-      int srtmLonIdx = Integer.parseInt(filename90.substring(5, 7).toLowerCase());
-      int srtmLatIdx = Integer.parseInt(filename90.substring(8, 10).toLowerCase());
-
-      int ilon_base = (srtmLonIdx - 1) * 5 - 180;
-      int ilat_base = 150 - srtmLatIdx * 5 - 90;
-
-      SrtmRaster raster90 = null;
-
-      File file90 = new File(new File(args[1]), filename90);
-      if (file90.exists()) {
-        System.out.println("reading " + file90);
-        raster90 = new SrtmData(file90).getRaster();
-      }
-
-      ConvertSrtmTile.doConvert(args[2], args[3], ilon_base, ilat_base, filename30, raster90);
-    }
-    br.close();
-  }
-
-
-}
diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/CreateElevationRasterImage.java b/brouter-map-creator/src/main/java/btools/mapcreator/CreateElevationRasterImage.java
new file mode 100644
index 000000000..935965f03
--- /dev/null
+++ b/brouter-map-creator/src/main/java/btools/mapcreator/CreateElevationRasterImage.java
@@ -0,0 +1,335 @@
+package btools.mapcreator;
+
+import java.awt.Color;
+import java.awt.image.BufferedImage;
+import java.awt.image.DataBufferInt;
+import java.io.BufferedInputStream;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.FileReader;
+import java.io.InputStream;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.TreeMap;
+
+import javax.imageio.ImageIO;
+
+
+public class CreateElevationRasterImage {
+
+  final static boolean DEBUG = false;
+
+  int[] data;
+  ElevationRaster lastSrtmRaster;
+  Map<String, ElevationRaster> srtmmap;
+  int lastSrtmLonIdx;
+  int lastSrtmLatIdx;
+  short maxElev = Short.MIN_VALUE;
+  short minElev = Short.MAX_VALUE;
+  String srtmdir;
+  boolean missingData;
+  Map<Short, Color> colorMap;
+
+
+  private void createImage(double lon, double lat, String dir, String imageName, int maxX, int maxY, int downscale, String format, String colors) throws Exception {
+    srtmdir = dir;
+    if (colors != null) {
+      loadColors(colors);
+    }
+    if (format.equals("hgt")) {
+      createImageFromHgt(lon, lat, dir, imageName, maxX, maxY);
+      return;
+    }
+    if (!format.equals("bef")) {
+      System.out.println("wrong format (bef|hgt)");
+      return;
+    }
+    srtmmap = new HashMap<>();
+    lastSrtmLonIdx = -1;
+    lastSrtmLatIdx = -1;
+    lastSrtmRaster = null;
+    NodeData n = new NodeData(1, lon, lat);
+    ElevationRaster srtm = srtmForNode(n.ilon, n.ilat);
+    if (srtm == null) {
+      System.out.println("no data");
+      return;
+    }
+    System.out.println("srtm " + srtm.toString());
+    //System.out.println("srtm elev " + srtm.getElevation(n.ilon, n.ilat));
+    double[] pos = getElevationPos(srtm, n.ilon, n.ilat);
+    //System.out.println("srtm pos " + Math.round(pos[0]) + " "  + Math.round(pos[1]));
+    short[] raster = srtm.eval_array;
+    int rasterX = srtm.ncols;
+    int rasterY = srtm.nrows;
+
+    int tileSize = 1000 / downscale;
+    int sizeX = (maxX);
+    int sizeY = (maxY);
+    int[] imgraster = new int[sizeX * sizeY];
+    for (int y = 0; y < sizeY; y++) {
+      for (int x = 0; x < sizeX; x++) {
+        //short e = getElevationXY(srtm, pos[0] + (sizeY - y) * downscale, pos[1] + (x * downscale));
+        short e = get(srtm, (int) Math.round(pos[0]) + (sizeY - y), x + (int) Math.round(pos[1]));
+        if (e != Short.MIN_VALUE && e < minElev) minElev = e;
+        if (e != Short.MIN_VALUE && e > maxElev) maxElev = e;
+
+        if (e == Short.MIN_VALUE) {
+          imgraster[sizeY * y + x] = 0xffff;
+        } else {
+          //imgraster[sizeY * y + x] = getColorForHeight((short)(e/4)); //(int)(e/4.);
+          imgraster[sizeY * y + x] = getColorForHeight(e);
+        }
+      }
+    }
+    System.out.println("srtm target " + sizeX + " " + sizeY + " (" + rasterX + " " + rasterY + ")" + "  min " + minElev + " max " + maxElev);
+
+    if (DEBUG) {
+      String out = "short ";
+      for (int i = 0; i < 100; i++) {
+        out += " " + get(srtm, sizeY - 0, i);
+      }
+      System.out.println(out);
+    }
+
+    BufferedImage argbImage = new BufferedImage(sizeX, sizeY, BufferedImage.TYPE_INT_ARGB);
+    data = ((DataBufferInt) argbImage.getRaster().getDataBuffer()).getData();
+
+    for (int y = 0; y < sizeY; y++) {
+      for (int x = 0; x < sizeX; x++) {
+        int v0 = imgraster[sizeX * y + x];
+
+        int rgb;
+        if (v0 != 0xffff)
+          rgb = 0xff000000 | v0; //(v0 << 8);
+        else
+          rgb = 0xff000000;
+        data[y * sizeX + x] = rgb;
+      }
+    }
+
+    ImageIO.write(argbImage, "png", new FileOutputStream(imageName));
+  }
+
+  private void createImageFromHgt(double lon, double lat, String dir, String imageName, int maxX, int maxY) throws Exception {
+    HgtReader rdr = new HgtReader(dir);
+    short[] data = rdr.getElevationDataFromHgt(lat, lon);
+    if (data == null) {
+      System.out.println("no data");
+      return;
+    }
+
+    int size = (data != null ? data.length : 0);
+    int rowlen = (int) Math.sqrt(size);
+    int sizeX = (maxX);
+    int sizeY = (maxY);
+    int[] imgraster = new int[sizeX * sizeY];
+
+    for (int y = 0; y < sizeY; y++) {
+      for (int x = 0; x < sizeX; x++) {
+        short e = data[(rowlen * y) + x];
+        if (e != HgtReader.HGT_VOID && e < minElev) minElev = e;
+        if (e != HgtReader.HGT_VOID && e > maxElev) maxElev = e;
+
+        if (e == HgtReader.HGT_VOID) {
+          imgraster[sizeY * y + x] = 0xffff;
+        } else if (e == 0) {
+          imgraster[sizeY * y + x] = 0xffff;
+        } else {
+          imgraster[sizeY * y + x] = getColorForHeight((short) (e));
+        }
+      }
+    }
+    System.out.println("hgt size " + rowlen + " x " + rowlen + "  min " + minElev + " max " + maxElev);
+    if (DEBUG) {
+      String out = "short ";
+      for (int i = 0; i < 100; i++) {
+        out += " " + data[i];
+      }
+      System.out.println(out);
+    }
+    BufferedImage argbImage = new BufferedImage(sizeX, sizeY, BufferedImage.TYPE_INT_ARGB);
+    int[] idata = ((DataBufferInt) argbImage.getRaster().getDataBuffer()).getData();
+
+    for (int y = 0; y < sizeY; y++) {
+      for (int x = 0; x < sizeX; x++) {
+        int v0 = imgraster[sizeX * y + x];
+
+        int rgb;
+        if (v0 != 0xffff)
+          rgb = 0xff000000 | v0; //(v0 << 8);
+        else
+          rgb = 0xff000000;
+        idata[y * sizeX + x] = rgb;
+      }
+    }
+
+    ImageIO.write(argbImage, "png", new FileOutputStream(imageName));
+
+  }
+
+  private void loadColors(String colors) {
+    if (DEBUG) System.out.println("colors=" + colors);
+    File colFile = new File(colors);
+    if (colFile.exists()) {
+      BufferedReader reader = null;
+      colorMap = new TreeMap<>();
+      try {
+        reader = new BufferedReader(new FileReader(colors));
+        String line = reader.readLine();
+
+        while (line != null) {
+          if (DEBUG) System.out.println(line);
+          String[] sa = line.split(",");
+          if (!line.startsWith("#") && sa.length == 4) {
+            short e = Short.valueOf(sa[0].trim());
+            short r = Short.valueOf(sa[1].trim());
+            short g = Short.valueOf(sa[2].trim());
+            short b = Short.valueOf(sa[3].trim());
+            colorMap.put(e, new Color(r, g, b));
+          }
+          // read next line
+          line = reader.readLine();
+        }
+
+      } catch (Exception e) {
+        e.printStackTrace();
+        colorMap = null;
+      } finally {
+        if (reader != null) {
+          try {
+            reader.close();
+          } catch (Exception e) {
+            e.printStackTrace();
+          }
+        }
+      }
+    } else {
+      System.out.println("color file " + colors + " not found");
+    }
+  }
+
+  public double[] getElevationPos(ElevationRaster srtm, int ilon, int ilat) {
+    double lon = ilon / 1000000. - 180.;
+    double lat = ilat / 1000000. - 90.;
+
+    double dcol = (lon - srtm.xllcorner) / srtm.cellsize - 0.5;
+    double drow = (lat - srtm.yllcorner) / srtm.cellsize - 0.5;
+    int row = (int) drow;
+    int col = (int) dcol;
+    if (col < 0) col = 0;
+    if (row < 0) row = 0;
+
+    return new double[]{drow, dcol};
+  }
+
+  private short get(ElevationRaster srtm, int r, int c) {
+    short e = srtm.eval_array[(srtm.nrows - 1 - r) * srtm.ncols + c];
+    if (e == Short.MIN_VALUE) missingData = true;
+    return e;
+  }
+
+  public short getElevationXY(ElevationRaster srtm, double drow, double dcol) {
+    int row = (int) drow;
+    int col = (int) dcol;
+    if (col < 0) col = 0;
+    if (col >= srtm.ncols - 1) col = srtm.ncols - 2;
+    if (row < 0) row = 0;
+    if (row >= srtm.nrows - 1) row = srtm.nrows - 2;
+    double wrow = drow - row;
+    double wcol = dcol - col;
+    missingData = false;
+
+    double eval = (1. - wrow) * (1. - wcol) * get(srtm, row, col)
+      + (wrow) * (1. - wcol) * get(srtm, row + 1, col)
+      + (1. - wrow) * (wcol) * get(srtm, row, col + 1)
+      + (wrow) * (wcol) * get(srtm, row + 1, col + 1);
+
+    return missingData ? Short.MIN_VALUE : (short) (eval * 4);
+  }
+
+
+  int getColorForHeight(short h) {
+    if (colorMap == null) {
+      colorMap = new TreeMap<>();
+      colorMap.put((short) 0, new Color(102, 153, 153));
+      colorMap.put((short) 1, new Color(0, 102, 0));
+      colorMap.put((short) 500, new Color(251, 255, 128));
+      colorMap.put((short) 1200, new Color(224, 108, 31));
+      colorMap.put((short) 2500, new Color(200, 55, 55));
+      colorMap.put((short) 4000, new Color(215, 244, 244));
+      colorMap.put((short) 8000, new Color(255, 244, 244));
+    }
+    Color lastColor = null;
+    short lastKey = 0;
+    for (Entry<Short, Color> entry : colorMap.entrySet()) {
+      short key = entry.getKey();
+      Color value = entry.getValue();
+      if (key == h) return value.getRGB();
+      if (lastColor != null && lastKey < h && key > h) {
+        double between = (double) (h - lastKey) / (key - lastKey);
+        return mixColors(value, lastColor, between);
+      }
+      lastColor = value;
+      lastKey = key;
+    }
+    return 0;
+  }
+
+  public int mixColors(Color color1, Color color2, double percent) {
+    double inverse_percent = 1.0 - percent;
+    int redPart = (int) (color1.getRed() * percent + color2.getRed() * inverse_percent);
+    int greenPart = (int) (color1.getGreen() * percent + color2.getGreen() * inverse_percent);
+    int bluePart = (int) (color1.getBlue() * percent + color2.getBlue() * inverse_percent);
+    return new Color(redPart, greenPart, bluePart).getRGB();
+  }
+
+  private ElevationRaster srtmForNode(int ilon, int ilat) throws Exception {
+    int srtmLonIdx = (ilon + 5000000) / 5000000;
+    int srtmLatIdx = (654999999 - ilat) / 5000000 - 100; // ugly negative rounding...
+
+    if (srtmLonIdx == lastSrtmLonIdx && srtmLatIdx == lastSrtmLatIdx) {
+      return lastSrtmRaster;
+    }
+    lastSrtmLonIdx = srtmLonIdx;
+    lastSrtmLatIdx = srtmLatIdx;
+
+    String slonidx = "0" + srtmLonIdx;
+    String slatidx = "0" + srtmLatIdx;
+    String filename = "srtm_" + slonidx.substring(slonidx.length() - 2) + "_" + slatidx.substring(slatidx.length() - 2);
+
+    lastSrtmRaster = srtmmap.get(filename);
+    if (lastSrtmRaster == null && !srtmmap.containsKey(filename)) {
+      File f = new File(new File(srtmdir), filename + ".bef");
+      if (f.exists()) {
+        System.out.println("*** reading: " + f);
+        try {
+          InputStream isc = new BufferedInputStream(new FileInputStream(f));
+          lastSrtmRaster = new ElevationRasterCoder().decodeRaster(isc);
+          isc.close();
+        } catch (Exception e) {
+          System.out.println("**** ERROR reading " + f + " ****");
+        }
+        srtmmap.put(filename, lastSrtmRaster);
+        return lastSrtmRaster;
+      }
+
+      srtmmap.put(filename, lastSrtmRaster);
+    }
+    return lastSrtmRaster;
+  }
+
+  public static void main(String[] args) throws Exception {
+    if (args.length < 6) {
+      System.out.println("usage: java CreateLidarImage <lon> <lat> <srtm-folder> <imageFileName> <maxX> <maxY> <downscale> [type] [color_file]");
+      System.out.println("\nwhere: type = [bef|hgt] downscale = [1|2|4|..]");
+      return;
+    }
+    String format = args.length >= 8 ? args[7] : "bef";
+    String colors = args.length == 9 ? args[8] : null;
+    new CreateElevationRasterImage().createImage(Double.parseDouble(args[0]), Double.parseDouble(args[1]), args[2], args[3],
+      Integer.parseInt(args[4]), Integer.parseInt(args[5]), Integer.parseInt(args[6]), format, colors);
+  }
+}
diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/SrtmRaster.java b/brouter-map-creator/src/main/java/btools/mapcreator/ElevationRaster.java
similarity index 98%
rename from brouter-map-creator/src/main/java/btools/mapcreator/SrtmRaster.java
rename to brouter-map-creator/src/main/java/btools/mapcreator/ElevationRaster.java
index 3a307bfe1..478811ce1 100644
--- a/brouter-map-creator/src/main/java/btools/mapcreator/SrtmRaster.java
+++ b/brouter-map-creator/src/main/java/btools/mapcreator/ElevationRaster.java
@@ -3,11 +3,11 @@
 import btools.util.ReducedMedianFilter;
 
 /**
- * Container for a srtm-raster + it's meta-data
+ * Container for a elevation raster + it's meta-data
  *
  * @author ab
  */
-public class SrtmRaster {
+public class ElevationRaster {
   public int ncols;
   public int nrows;
   public boolean halfcol;
diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/RasterCoder.java b/brouter-map-creator/src/main/java/btools/mapcreator/ElevationRasterCoder.java
similarity index 80%
rename from brouter-map-creator/src/main/java/btools/mapcreator/RasterCoder.java
rename to brouter-map-creator/src/main/java/btools/mapcreator/ElevationRasterCoder.java
index 233e3ea88..02a841dd2 100644
--- a/brouter-map-creator/src/main/java/btools/mapcreator/RasterCoder.java
+++ b/brouter-map-creator/src/main/java/btools/mapcreator/ElevationRasterCoder.java
@@ -1,15 +1,20 @@
 package btools.mapcreator;
 
-import java.io.*;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
 
-import btools.util.*;
+import btools.util.MixCoderDataInputStream;
+import btools.util.MixCoderDataOutputStream;
 
 //
 // Encode/decode a raster
 //
 
-public class RasterCoder {
-  public void encodeRaster(SrtmRaster raster, OutputStream os) throws IOException {
+public class ElevationRasterCoder {
+  public void encodeRaster(ElevationRaster raster, OutputStream os) throws IOException {
     DataOutputStream dos = new DataOutputStream(os);
 
     long t0 = System.currentTimeMillis();
@@ -28,12 +33,12 @@ public void encodeRaster(SrtmRaster raster, OutputStream os) throws IOException
     System.out.println("finished encoding in " + (t1 - t0) + " ms");
   }
 
-  public SrtmRaster decodeRaster(InputStream is) throws IOException {
+  public ElevationRaster decodeRaster(InputStream is) throws IOException {
     DataInputStream dis = new DataInputStream(is);
 
     long t0 = System.currentTimeMillis();
 
-    SrtmRaster raster = new SrtmRaster();
+    ElevationRaster raster = new ElevationRaster();
     raster.ncols = dis.readInt();
     raster.nrows = dis.readInt();
     raster.halfcol = dis.readBoolean();
@@ -45,7 +50,7 @@ public SrtmRaster decodeRaster(InputStream is) throws IOException {
 
     _decodeRaster(raster, is);
 
-    raster.usingWeights = raster.ncols > 6001;
+    raster.usingWeights = false; // raster.ncols > 6001;
 
     long t1 = System.currentTimeMillis();
     System.out.println("finished decoding in " + (t1 - t0) + " ms ncols=" + raster.ncols + " nrows=" + raster.nrows);
@@ -53,7 +58,7 @@ public SrtmRaster decodeRaster(InputStream is) throws IOException {
   }
 
 
-  private void _encodeRaster(SrtmRaster raster, OutputStream os) throws IOException {
+  private void _encodeRaster(ElevationRaster raster, OutputStream os) throws IOException {
     MixCoderDataOutputStream mco = new MixCoderDataOutputStream(os);
     int nrows = raster.nrows;
     int ncols = raster.ncols;
@@ -78,7 +83,7 @@ private void _encodeRaster(SrtmRaster raster, OutputStream os) throws IOExceptio
     mco.flush();
   }
 
-  private void _decodeRaster(SrtmRaster raster, InputStream is) throws IOException {
+  private void _decodeRaster(ElevationRaster raster, InputStream is) throws IOException {
     MixCoderDataInputStream mci = new MixCoderDataInputStream(is);
     int nrows = raster.nrows;
     int ncols = raster.ncols;
diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/ElevationRasterTileConverter.java b/brouter-map-creator/src/main/java/btools/mapcreator/ElevationRasterTileConverter.java
new file mode 100644
index 000000000..9b251fc2b
--- /dev/null
+++ b/brouter-map-creator/src/main/java/btools/mapcreator/ElevationRasterTileConverter.java
@@ -0,0 +1,546 @@
+package btools.mapcreator;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedOutputStream;
+import java.io.BufferedReader;
+import java.io.DataInputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.util.Arrays;
+import java.util.Locale;
+import java.util.StringTokenizer;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+public class ElevationRasterTileConverter {
+
+  public static final boolean DEBUG = false;
+
+  public static final short NODATA2 = -32767; // hgt-formats nodata
+  public static final short NODATA = Short.MIN_VALUE;
+
+  private static final String HGT_FILE_EXT = ".hgt";
+  private static final int HGT_BORDER_OVERLAP = 1;
+  private static final int HGT_3ASEC_ROWS = 1201; // 3 arc second resolution (90m)
+  private static final int HGT_3ASEC_FILE_SIZE = HGT_3ASEC_ROWS * HGT_3ASEC_ROWS * Short.BYTES;
+  private static final int HGT_1ASEC_ROWS = 3601; // 1 arc second resolution (30m)
+  private static final int SRTM3_ROW_LENGTH = 1200; // number of elevation values per line
+  private static final int SRTM1_ROW_LENGTH = 3600;
+  private static final boolean SRTM_NO_ZERO = true;
+
+  private int NROWS;
+  private int NCOLS;
+  private int ROW_LENGTH;
+  private short[] imagePixels;
+
+  /**
+   * This generates elevation raster files with a 5x5 degree scope
+   * The output can be for 1sec (18000x18000 points)
+   * or for 3sec (6000x6000 points)
+   * When using 1sec input files a not found area can be called from 3sec pool
+   * The input can be 1x1 degree 1sec/3sec hgt files (also packed as zip)
+   * or 5x5 degree 3sec asc files (delivered as zip)
+   * Arguments for single file generation:
+   * ElevationRasterTileConverter <srtm-filename | all> <hgt-data-dir> <srtm-output-dir> [arc seconds (1 or 3,default=3)] [hgt-fallback-data-dir]
+   * Samples
+   * $ ... ElevationRasterTileConverter srtm_34_-1 ./srtm/hgt3sec ./srtm/srtm3_bef
+   * $ ... ElevationRasterTileConverter srtm_34_-1 ./srtm/hgt1sec ./srtm/srtm1_bef 1
+   * $ ... ElevationRasterTileConverter srtm_34_-1 ./srtm/hgt1sec ./srtm/srtm1_bef 1 ./srtm/hgt3sec
+   * <p>
+   * Arguments for multi file generation (world wide):
+   * $ ... ElevationRasterTileConverter all ./srtm/hgt3sec ./srtm/srtm3_bef
+   * $ ... ElevationRasterTileConverter all ./srtm/hgt1sec ./srtm/srtm1_bef 1
+   * $ ... ElevationRasterTileConverter all ./srtm/hgt1sec ./srtm/srtm1_bef 1 ./srtm/hgt3sec
+   *
+   * @param args
+   * @throws Exception
+   */
+  public static void main(String[] args) throws Exception {
+    if (args.length == 3 || args.length == 4 || args.length == 5) {
+      String filename90 = args[0];
+      if ("all".equals(filename90)) {
+        //if (DEBUG)
+        System.out.println("raster convert all ");
+        new ElevationRasterTileConverter().doConvertAll(args[1], args[2], (args.length > 3 ? args[3] : null), (args.length == 5 ? args[4] : null));
+        return;
+      }
+      // old filenames only
+      String filename30 = filename90 + ".bef"; //filename90.substring(0, filename90.length() - 3) + "bef";
+
+      int srtmLonIdx = Integer.parseInt(filename90.substring(5, 7).toLowerCase());
+      int srtmLatIdx = Integer.parseInt(filename90.substring(8, 10).toLowerCase());
+
+      int ilon_base = (srtmLonIdx - 1) * 5 - 180;
+      int ilat_base = 150 - srtmLatIdx * 5 - 90;
+      int row_length = SRTM3_ROW_LENGTH;
+      String fallbackdir = null;
+      if (args.length > 3) {
+        row_length = (Integer.parseInt(args[3]) == 1 ? SRTM1_ROW_LENGTH : SRTM3_ROW_LENGTH);
+        fallbackdir = (args.length == 5 ? args[4] : null);
+      }
+      //if (DEBUG)
+      System.out.println("raster convert " + ilon_base + " " + ilat_base + " from " + srtmLonIdx + " " + srtmLatIdx + " f: " + filename90 + " rowl " + row_length);
+
+      new ElevationRasterTileConverter().doConvert(args[1], ilon_base, ilat_base, args[2] + "/" + filename30, row_length, fallbackdir);
+    } else {
+      System.out.println("usage: java <srtm-filename> <hgt-data-dir> <srtm-output-dir> [arc seconds (1 or 3,default=3)] [hgt-fallback-data-dir]");
+      System.out.println("or     java all <hgt-data-dir> <srtm-output-dir> [arc seconds (1 or 3, default=3)] [hgt-fallback-data-dir]");
+      return;
+    }
+  }
+
+  private void doConvertAll(String hgtdata, String outdir, String rlen, String hgtfallbackdata) throws Exception {
+    int row_length = SRTM3_ROW_LENGTH;
+    if (rlen != null) {
+      row_length = (Integer.parseInt(rlen) == 1 ? SRTM1_ROW_LENGTH : SRTM3_ROW_LENGTH);
+    }
+    String filename30;
+    for (int ilon_base = -180; ilon_base < 180; ilon_base += 5) {
+      for (int ilat_base = 85; ilat_base > -90; ilat_base -= 5) {
+        if (PosUnifier.UseRasterRd5FileName) {
+          filename30 = genFilenameRd5(ilon_base, ilat_base);
+        } else {
+          filename30 = genFilenameOld(ilon_base, ilat_base);
+        }
+        if (DEBUG)
+          System.out.println("lidar convert all: " + filename30);
+        doConvert(hgtdata, ilon_base, ilat_base, outdir + "/" + filename30, row_length, hgtfallbackdata);
+      }
+    }
+  }
+
+  static String genFilenameOld(int ilon_base, int ilat_base) {
+    int srtmLonIdx = ((ilon_base + 180) / 5) + 1;
+    int srtmLatIdx = (60 - ilat_base) / 5;
+    return String.format(Locale.US, "srtm_%02d_%02d.bef", srtmLonIdx, srtmLatIdx);
+  }
+
+  static String genFilenameRd5(int ilon_base, int ilat_base) {
+    return String.format("srtm_%s_%s.bef", ilon_base < 0 ? "W" + (-ilon_base) : "E" + ilon_base,
+      ilat_base < 0 ? "S" + (-ilat_base) : "N" + ilat_base);
+  }
+
+  private void readHgtZip(String filename, int rowOffset, int colOffset, int row_length, int scale) throws Exception {
+    ZipInputStream zis = new ZipInputStream(new BufferedInputStream(new FileInputStream(filename)));
+    try {
+      for (; ; ) {
+        ZipEntry ze = zis.getNextEntry();
+        if (ze == null) break;
+        if (ze.getName().toLowerCase().endsWith(HGT_FILE_EXT)) {
+          readHgtFromStream(zis, rowOffset, colOffset, row_length, scale);
+          return;
+        }
+      }
+    } finally {
+      zis.close();
+    }
+  }
+
+  private void readHgtFromStream(InputStream is, int rowOffset, int colOffset, int rowLength, int scale)
+    throws Exception {
+    DataInputStream dis = new DataInputStream(new BufferedInputStream(is));
+    for (int ir = 0; ir < rowLength; ir++) {
+      int row = rowOffset + ir * scale;
+
+      for (int ic = 0; ic < rowLength; ic++) {
+        int col = colOffset + ic * scale;
+
+        int i1 = dis.read(); // msb first!
+        int i0 = dis.read();
+
+        if (i0 == -1 || i1 == -1)
+          throw new RuntimeException("unexpected end of file reading hgt entry!");
+
+        short val = (short) ((i1 << 8) | i0);
+
+        if (val == NODATA2) {
+          val = NODATA;
+        }
+        if (scale == 3) {
+          setPixel(row, col, val);
+          setPixel(row + 1, col, val);
+          setPixel(row + 2, col, val);
+          setPixel(row, col + 1, val);
+          setPixel(row + 1, col + 1, val);
+          setPixel(row + 2, col + 1, val);
+          setPixel(row, col + 2, val);
+          setPixel(row + 1, col + 2, val);
+          setPixel(row + 2, col + 2, val);
+        } else {
+          setPixel(row, col, val);
+        }
+      }
+    }
+  }
+
+  private void readHgtFile(File file, int rowOffset, int colOffset, int row_length, int scale)
+    throws Exception {
+
+    if (DEBUG)
+      System.out.println("read: " + file + " " + row_length);
+
+    FileInputStream fis = new FileInputStream(file);
+    try {
+      readHgtFromStream(fis, rowOffset, colOffset, row_length, scale);
+    } finally {
+      fis.close();
+    }
+  }
+
+  /*
+  private void readFallbackFile(File file, int rowOffset, int colOffset, int row_length)
+    throws Exception {
+    int rowLength;
+    int scale;
+    if (file.length() > HGT_3ASEC_FILE_SIZE) {
+      rowLength = HGT_1ASEC_ROWS;
+      scale = 1;
+    } else {
+      rowLength = HGT_3ASEC_ROWS;
+      scale = 3;
+    }
+    if (DEBUG)
+      System.out.println("read fallback: " + file + " " + rowLength);
+
+    FileInputStream fis = new FileInputStream(file);
+    try {
+      readHgtFromStream(fis, rowOffset, colOffset, rowLength, scale);
+    } finally {
+      fis.close();
+    }
+  }
+  */
+
+  private void readAscZip(File file, ElevationRaster raster) throws Exception {
+
+    ZipInputStream zis = new ZipInputStream(new BufferedInputStream(new FileInputStream(file)));
+    try {
+      for (; ; ) {
+        ZipEntry ze = zis.getNextEntry();
+        if (ze.getName().endsWith(".asc")) {
+          readAscFromStream(zis, raster);
+          return;
+        }
+      }
+    } finally {
+      zis.close();
+    }
+  }
+
+  private String secondToken(String s) {
+    StringTokenizer tk = new StringTokenizer(s, " ");
+    tk.nextToken();
+    return tk.nextToken();
+  }
+
+  private void readAscFromStream(InputStream is, ElevationRaster raster) throws Exception {
+    BufferedReader br = new BufferedReader(new InputStreamReader(is));
+    int linenr = 0;
+    for (; ; ) {
+      linenr++;
+      if (linenr <= 6) {
+        String line = br.readLine();
+        if (linenr == 1)
+          raster.ncols = Integer.parseInt(secondToken(line));
+        else if (linenr == 2)
+          raster.nrows = Integer.parseInt(secondToken(line));
+        else if (linenr == 3)
+          raster.xllcorner = Double.parseDouble(secondToken(line));
+        else if (linenr == 4)
+          raster.yllcorner = Double.parseDouble(secondToken(line));
+        else if (linenr == 5)
+          raster.cellsize = Double.parseDouble(secondToken(line));
+        else if (linenr == 6) {
+          // nodata ignored here ( < -250 assumed nodata... )
+          // raster.noDataValue = Short.parseShort( secondToken( line ) );
+          raster.eval_array = new short[raster.ncols * raster.nrows];
+        }
+      } else {
+        int row = 0;
+        int col = 0;
+        int n = 0;
+        boolean negative = false;
+        for (; ; ) {
+          int c = br.read();
+          if (c < 0)
+            break;
+          if (c == ' ') {
+            if (negative)
+              n = -n;
+            short val = n < -250 ? Short.MIN_VALUE : (short) (n);
+
+            raster.eval_array[row * raster.ncols + col] = val;
+            if (++col == raster.ncols) {
+              col = 0;
+              ++row;
+            }
+            n = 0;
+            negative = false;
+          } else if (c >= '0' && c <= '9') {
+            n = 10 * n + (c - '0');
+          } else if (c == '-') {
+            negative = true;
+          }
+        }
+        break;
+      }
+    }
+    br.close();
+  }
+
+
+  private void setPixel(int row, int col, short val) {
+    if (row >= 0 && row < NROWS && col >= 0 && col < NCOLS) {
+      imagePixels[row * NCOLS + col] = val;
+    }
+  }
+
+  private short getPixel(int row, int col) {
+    if (row >= 0 && row < NROWS && col >= 0 && col < NCOLS) {
+      return imagePixels[row * NCOLS + col];
+    }
+    return NODATA;
+  }
+
+
+  public void doConvert(String inputDir, int lonDegreeStart, int latDegreeStart, String outputFile, int row_length, String hgtfallbackdata) throws Exception {
+    int extraBorder = 0;
+
+    //List<String> foundList = new ArrayList<>();
+    //List<String> notfoundList = new ArrayList<>();
+
+    boolean hgtfound = false;
+    boolean ascfound = false;
+    String filename = null;
+    //if (row_length == SRTM1_ROW_LENGTH)
+    {
+      // check for sources w/o border
+      for (int latIdx = 0; latIdx < 5; latIdx++) {
+        int latDegree = latDegreeStart + latIdx;
+
+        for (int lonIdx = 0; lonIdx < 5; lonIdx++) {
+          int lonDegree = lonDegreeStart + lonIdx;
+
+          filename = inputDir + "/" + formatLat(latDegree) + formatLon(lonDegree) + ".zip";
+          File f = new File(filename);
+          if (f.exists() && f.length() > 0) {
+            hgtfound = true;
+            break;
+          }
+          filename = filename.substring(0, filename.length() - 4) + ".hgt";
+          f = new File(filename);
+          if (f.exists() && f.length() > 0) {
+            hgtfound = true;
+            break;
+          }
+        }
+      }
+      if (!hgtfound) {
+        filename = inputDir + "/" + genFilenameOld(lonDegreeStart, latDegreeStart).substring(0, 10) + ".zip";
+        File f = new File(filename);
+        if (f.exists() && f.length() > 0) {
+          ascfound = true;
+        }
+      }
+    }
+    if (hgtfound) { // init when found
+      NROWS = 5 * row_length + 1 + 2 * extraBorder;
+      NCOLS = 5 * row_length + 1 + 2 * extraBorder;
+      imagePixels = new short[NROWS * NCOLS]; // 650 MB !
+
+      // prefill as NODATA
+      Arrays.fill(imagePixels, NODATA);
+    } else if (!ascfound) {
+      if (DEBUG)
+        System.out.println("none data: " + lonDegreeStart + " " + latDegreeStart);
+      return;
+    }
+
+    if (hgtfound) {
+      for (int latIdx = -1; latIdx <= 5; latIdx++) {
+        int latDegree = latDegreeStart + latIdx;
+        int rowOffset = extraBorder + (4 - latIdx) * row_length;
+
+        for (int lonIdx = -1; lonIdx <= 5; lonIdx++) {
+          int lonDegree = lonDegreeStart + lonIdx;
+          int colOffset = extraBorder + lonIdx * row_length;
+
+          filename = inputDir + "/" + formatLat(latDegree) + formatLon(lonDegree) + ".zip";
+          File f = new File(filename);
+          if (f.exists() && f.length() > 0) {
+            if (DEBUG)
+              System.out.println("exist: " + filename);
+            readHgtZip(filename, rowOffset, colOffset, row_length + 1, 1);
+            continue;
+          }
+          filename = filename.substring(0, filename.length() - 4) + ".hgt";
+          f = new File(filename);
+          if (f.exists() && f.length() > 0) {
+            if (DEBUG)
+              System.out.println("exist: " + filename);
+            readHgtFile(f, rowOffset, colOffset, row_length + 1, 1);
+            continue;
+          } else {
+            if (hgtfallbackdata != null) {
+              filename = hgtfallbackdata + "/" + formatLat(latDegree) + formatLon(lonDegree) + ".hgt";
+              f = new File(filename);
+              if (f.exists() && f.length() > 0) {
+                readHgtFile(f, rowOffset, colOffset, SRTM3_ROW_LENGTH + 1, 3);
+                continue;
+              }
+              filename = filename.substring(0, filename.length() - 4) + ".zip";
+              f = new File(filename);
+              if (f.exists() && f.length() > 0) {
+                readHgtZip(filename, rowOffset, colOffset, SRTM3_ROW_LENGTH + 1, 3);
+              } else {
+                if (DEBUG)
+                  System.out.println("none : " + filename);
+              }
+            }
+
+          }
+        }
+      }
+
+      // post fill zero
+      if (SRTM_NO_ZERO) {
+        for (int row = 0; row < NROWS; row++) {
+          for (int col = 0; col < NCOLS; col++) {
+            if (imagePixels[row * NCOLS + col] == 0) imagePixels[row * NCOLS + col] = NODATA;
+          }
+        }
+      }
+    }
+
+    boolean halfCol5 = false; // no halfcol tiles in lidar data (?)
+
+
+    ElevationRaster raster = new ElevationRaster();
+    if (hgtfound) {
+      raster.nrows = NROWS;
+      raster.ncols = NCOLS;
+      raster.halfcol = halfCol5;
+      raster.noDataValue = NODATA;
+      raster.cellsize = 1. / row_length;
+      raster.xllcorner = lonDegreeStart - (0.5 + extraBorder) * raster.cellsize;
+      raster.yllcorner = latDegreeStart - (0.5 + extraBorder) * raster.cellsize;
+      raster.eval_array = imagePixels;
+    }
+
+    if (ascfound) {
+      File f = new File(filename);
+      readAscZip(f, raster);
+    }
+
+    // encode the raster
+    OutputStream os = new BufferedOutputStream(new FileOutputStream(outputFile));
+    new ElevationRasterCoder().encodeRaster(raster, os);
+    os.close();
+
+    // decode the raster
+    InputStream is = new BufferedInputStream(new FileInputStream(outputFile));
+    ElevationRaster raster2 = new ElevationRasterCoder().decodeRaster(is);
+    is.close();
+
+    short[] pix2 = raster2.eval_array;
+    if (pix2.length != raster.eval_array.length)
+      throw new RuntimeException("length mismatch!");
+
+    // compare decoding result
+    for (int row = 0; row < raster.nrows; row++) {
+      int colstep = halfCol5 ? 2 : 1;
+      for (int col = 0; col < raster.ncols; col += colstep) {
+        int idx = row * raster.ncols + col;
+        short p2 = pix2[idx];
+        if (p2 != raster.eval_array[idx]) {
+          throw new RuntimeException("content mismatch: p2=" + p2 + " p1=" + raster.eval_array[idx]);
+        }
+      }
+    }
+    imagePixels = null;
+  }
+
+  private static String formatLon(int lon) {
+    if (lon >= 180)
+      lon -= 180; // TODO: w180 oder E180 ?
+
+    String s = "E";
+    if (lon < 0) {
+      lon = -lon;
+      s = "W";
+    }
+    String n = "000" + lon;
+    return s + n.substring(n.length() - 3);
+  }
+
+  private static String formatLat(int lat) {
+    String s = "N";
+    if (lat < 0) {
+      lat = -lat;
+      s = "S";
+    }
+    String n = "00" + lat;
+    return s + n.substring(n.length() - 2);
+  }
+
+
+  public ElevationRaster getRaster(File f, double lon, double lat) throws Exception {
+    long fileSize;
+    InputStream inputStream;
+
+    if (f.getName().toLowerCase().endsWith(".zip")) {
+      ZipInputStream zis = new ZipInputStream(new BufferedInputStream(new FileInputStream(f)));
+      for (; ; ) {
+        ZipEntry ze = zis.getNextEntry();
+        if (ze == null) {
+          throw new FileNotFoundException(f.getName() + " doesn't contain a " + HGT_FILE_EXT + " file.");
+        }
+        if (ze.getName().toLowerCase().endsWith(HGT_FILE_EXT)) {
+          fileSize = ze.getSize();
+          inputStream = zis;
+          break;
+        }
+      }
+    } else {
+      fileSize = f.length();
+      inputStream = new FileInputStream(f);
+    }
+
+    int rowLength;
+    if (fileSize > HGT_3ASEC_FILE_SIZE) {
+      rowLength = HGT_1ASEC_ROWS;
+    } else {
+      rowLength = HGT_3ASEC_ROWS;
+    }
+
+    // stay at 1 deg * 1 deg raster
+    NROWS = rowLength;
+    NCOLS = rowLength;
+
+    imagePixels = new short[NROWS * NCOLS];
+
+    // prefill as NODATA
+    Arrays.fill(imagePixels, NODATA);
+    readHgtFromStream(inputStream, 0, 0, rowLength, 1);
+    inputStream.close();
+
+    ElevationRaster raster = new ElevationRaster();
+    raster.nrows = NROWS;
+    raster.ncols = NCOLS;
+    raster.halfcol = false; // assume full resolution
+    raster.noDataValue = NODATA;
+    raster.cellsize = 1. / (double) (rowLength - HGT_BORDER_OVERLAP);
+    raster.xllcorner = (int) (lon < 0 ? lon - 1 : lon); //onDegreeStart - raster.cellsize;
+    raster.yllcorner = (int) (lat < 0 ? lat - 1 : lat); //latDegreeStart - raster.cellsize;
+    raster.eval_array = imagePixels;
+
+    return raster;
+  }
+
+
+}
diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/HgtReader.java b/brouter-map-creator/src/main/java/btools/mapcreator/HgtReader.java
new file mode 100644
index 000000000..f161d7dc4
--- /dev/null
+++ b/brouter-map-creator/src/main/java/btools/mapcreator/HgtReader.java
@@ -0,0 +1,342 @@
+// License: GPL. For details, see LICENSE file.
+package btools.mapcreator;
+
+import java.io.BufferedInputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.ShortBuffer;
+import java.nio.channels.FileChannel;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+/**
+ * adapted from https://github.com/JOSM/josm-plugins/blob/master/ElevationProfile/src/org/openstreetmap/josm/plugins/elevation/HgtReader.java
+ * <p>
+ * Class HgtReader reads data from SRTM HGT files. Currently this class is restricted to a resolution of 3 arc seconds.
+ * <p>
+ * SRTM data files are available at the <a href="http://dds.cr.usgs.gov/srtm/version2_1/SRTM3">NASA SRTM site</a>
+ *
+ * @author Oliver Wieland &lt;oliver.wieland@online.de&gt;
+ */
+public class HgtReader {
+  final static boolean DEBUG = false;
+
+  private static final int SECONDS_PER_MINUTE = 60;
+
+  public static final String HGT_EXT = ".hgt";
+  public static final String ZIP_EXT = ".zip";
+
+  // alter these values for different SRTM resolutions
+  public static final int HGT3_RES = 3; // resolution in arc seconds
+  public static final int HGT3_ROW_LENGTH = 1201; // number of elevation values per line
+  public static final int HGT_VOID = -32768; // magic number which indicates 'void data' in HGT file
+  public static final int HGT1_RES = 1;  // <<- The new SRTM is 1-ARCSEC
+  public static final int HGT1_ROW_LENGTH = 3601; //-- New file resolution is 3601x3601
+  /**
+   * The 'no elevation' data magic.
+   */
+  public static double NO_ELEVATION = Double.NaN;
+
+  private static String srtmFolder = "";
+
+  private static final Map<String, ShortBuffer> cache = new HashMap<>();
+
+  public HgtReader(String folder) {
+    srtmFolder = folder;
+  }
+
+  public static double getElevationFromHgt(double lat, double lon) {
+    try {
+      String file = getHgtFileName(lat, lon);
+      if (DEBUG) System.out.println("HGT buffer " + file + " for " + lat + " " + lon);
+
+      // given area in cache?
+      if (!cache.containsKey(file)) {
+
+        // fill initial cache value. If no file is found, then
+        // we use it as a marker to indicate 'file has been searched
+        // but is not there'
+        cache.put(file, null);
+        // Try all resource directories
+        //for (String location : Main.pref.getAllPossiblePreferenceDirs())
+        {
+          String fullPath = new File(srtmFolder, file + HGT_EXT).getPath();
+          File f = new File(fullPath);
+          if (f.exists()) {
+            // found something: read HGT file...
+            ShortBuffer data = readHgtFile(fullPath);
+            // ... and store result in cache
+            cache.put(file, data);
+            //break;
+          } else {
+            fullPath = new File(srtmFolder, file + ZIP_EXT).getPath();
+            f = new File(fullPath);
+            if (f.exists()) {
+              ZipInputStream zis = new ZipInputStream(new BufferedInputStream(new FileInputStream(f)));
+              try {
+                for (; ; ) {
+                  ZipEntry ze = zis.getNextEntry();
+                  if (ze == null) break;
+                  if (ze.getName().toLowerCase().endsWith(HGT_EXT)) {
+                    // System.out.println("read zip " + ze.getName());
+                    ShortBuffer data = readHgtStream(zis);
+                    // ... and store result in cache
+                    cache.put(file, data);
+                    break;
+                  }
+                  zis.closeEntry();
+                }
+              } finally {
+                zis.close();
+              }
+            }
+          }
+          System.out.println("*** reading: " + f.getName() + "  " + cache.get(file));
+        }
+      }
+
+      // read elevation value
+      return readElevation(lat, lon);
+    } catch (FileNotFoundException e) {
+      System.err.println("HGT Get elevation " + lat + ", " + lon + " failed: => " + e.getMessage());
+      // no problem... file not there
+      return NO_ELEVATION;
+    } catch (Exception ioe) {
+      // oops...
+      ioe.printStackTrace(System.err);
+      // fallback
+      return NO_ELEVATION;
+    }
+  }
+
+  public static short[] getElevationDataFromHgt(double lat, double lon) {
+    try {
+      if (lon < 0) lon += 1;
+      if (lat < 0) lat += 1;
+      String file = getHgtFileName(lat, lon);
+      if (DEBUG) System.out.println("HGT buffer " + file + " for " + lat + " " + lon);
+
+      ShortBuffer data = null;
+
+      // Try all resource directories
+      //for (String location : Main.pref.getAllPossiblePreferenceDirs())
+
+      String fullPath = new File(srtmFolder, file + HGT_EXT).getPath();
+      File f = new File(fullPath);
+      if (f.exists()) {
+        // found something: read HGT file...
+        data = readHgtFile(fullPath);
+      } else {
+        fullPath = new File(srtmFolder, file + ZIP_EXT).getPath();
+        f = new File(fullPath);
+        if (f.exists()) {
+          ZipInputStream zis = new ZipInputStream(new BufferedInputStream(new FileInputStream(f)));
+          try {
+            for (; ; ) {
+              ZipEntry ze = zis.getNextEntry();
+              if (ze == null) break;
+              if (ze.getName().toLowerCase().endsWith(HGT_EXT)) {
+                // System.out.println("read zip " + ze.getName());
+                data = readHgtStream(zis);
+                break;
+              }
+              zis.closeEntry();
+            }
+          } finally {
+            zis.close();
+          }
+        }
+      }
+
+
+      System.out.println("*** reading: " + f.getName() + "  " + (data != null ? data.limit() : -1));
+      if (data != null) {
+        short[] array = new short[data.limit()];
+        data.get(array);
+        return array;
+      }
+      return null;
+    } catch (FileNotFoundException e) {
+      System.err.println("HGT Get elevation " + lat + ", " + lon + " failed: => " + e.getMessage());
+      // no problem... file not there
+      return null;
+    } catch (Exception ioe) {
+      // oops...
+      ioe.printStackTrace(System.err);
+      // fallback
+      return null;
+    }
+  }
+
+  @SuppressWarnings("resource")
+  private static ShortBuffer readHgtFile(String file) throws Exception {
+    if (file == null) throw new Exception("no hgt file " + file);
+
+    FileChannel fc = null;
+    ShortBuffer sb = null;
+    try {
+      // Eclipse complains here about resource leak on 'fc' - even with 'finally' clause???
+      fc = new FileInputStream(file).getChannel();
+      // choose the right endianness
+
+      ByteBuffer bb = ByteBuffer.allocateDirect((int) fc.size());
+      while (bb.remaining() > 0) fc.read(bb);
+
+      bb.flip();
+      //sb = bb.order(ByteOrder.LITTLE_ENDIAN).asShortBuffer();
+      sb = bb.order(ByteOrder.BIG_ENDIAN).asShortBuffer();
+    } finally {
+      if (fc != null) fc.close();
+    }
+
+    return sb;
+  }
+
+  // @SuppressWarnings("resource")
+  private static ShortBuffer readHgtStream(InputStream zis) throws Exception {
+    if (zis == null) throw new Exception("no hgt stream ");
+
+    ShortBuffer sb = null;
+    try {
+      // choose the right endianness
+
+      byte[] bytes = zis.readAllBytes();
+      ByteBuffer bb = ByteBuffer.allocate(bytes.length);
+      bb.put(bytes, 0, bytes.length);
+      //while (bb.remaining() > 0) zis.read(bb, 0, size);
+
+      //ByteBuffer bb = ByteBuffer.allocate(zis.available());
+      //Channels.newChannel(zis).read(bb);
+      bb.flip();
+      //sb = bb.order(ByteOrder.LITTLE_ENDIAN).asShortBuffer();
+      sb = bb.order(ByteOrder.BIG_ENDIAN).asShortBuffer();
+    } finally {
+
+    }
+
+    return sb;
+  }
+
+  /**
+   * Reads the elevation value for the given coordinate.
+   * <p>
+   * See also <a href="http://gis.stackexchange.com/questions/43743/how-to-extract-elevation-from-hgt-file">stackexchange.com</a>
+   *
+   * @param lat, lon the coordinate to get the elevation data for
+   * @return the elevation value or <code>Double.NaN</code>, if no value is present
+   */
+  public static double readElevation(double lat, double lon) {
+    String tag = getHgtFileName(lat, lon);
+
+    ShortBuffer sb = cache.get(tag);
+
+    if (sb == null) {
+      return NO_ELEVATION;
+    }
+
+    if (DEBUG) System.out.println("HGT buffer size " + sb.capacity() + " limit " + sb.limit());
+    try {
+      int rowLength = HGT3_ROW_LENGTH;
+      int resolution = HGT3_RES;
+      if (sb.capacity() > (HGT3_ROW_LENGTH * HGT3_ROW_LENGTH)) {
+        rowLength = HGT1_ROW_LENGTH;
+        resolution = HGT1_RES;
+      }
+      // see http://gis.stackexchange.com/questions/43743/how-to-extract-elevation-from-hgt-file
+      double fLat = frac(lat) * SECONDS_PER_MINUTE;
+      double fLon = frac(lon) * SECONDS_PER_MINUTE;
+
+      // compute offset within HGT file
+      int row = (int) Math.round((fLat) * SECONDS_PER_MINUTE / resolution);
+      int col = (int) Math.round((fLon) * SECONDS_PER_MINUTE / resolution);
+      if (lon < 0) col = rowLength - col - 1;
+      if (lat > 0) row = rowLength - row - 1;
+
+
+      //row = rowLength - row;
+      int cell = (rowLength * (row)) + col;
+      //int cell = ((rowLength * (latitude)) + longitude);
+
+      if (DEBUG)
+        System.out.println("Read HGT elevation data from row/col/cell " + row + "," + col + ", " + cell + ", " + sb.limit());
+
+      // valid position in buffer?
+      if (cell < sb.limit()) {
+        short ele = sb.get(cell);
+        // check for data voids
+        if (ele == HGT_VOID) {
+          return NO_ELEVATION;
+        } else {
+          return ele;
+        }
+      } else {
+        return NO_ELEVATION;
+      }
+    } catch (Exception e) {
+      System.err.println("error at " + lon + " " + lat + " ");
+      e.printStackTrace();
+    }
+    return NO_ELEVATION;
+  }
+
+  /**
+   * Gets the associated HGT file name for the given way point. Usually the
+   * format is <tt>[N|S]nn[W|E]mmm.hgt</tt> where <i>nn</i> is the integral latitude
+   * without decimals and <i>mmm</i> is the longitude.
+   *
+   * @param llat,llon the coordinate to get the filename for
+   * @return the file name of the HGT file
+   */
+  public static String getHgtFileName(double llat, double llon) {
+    int lat = (int) llat;
+    int lon = (int) llon;
+
+    String latPref = "N";
+    if (lat < 0) {
+      latPref = "S";
+      lat = -lat + 1;
+    }
+    String lonPref = "E";
+    if (lon < 0) {
+      lonPref = "W";
+      lon = -lon + 1;
+    }
+
+    return String.format("%s%02d%s%03d", latPref, lat, lonPref, lon);
+  }
+
+  public static double frac(double d) {
+    long iPart;
+    double fPart;
+
+    // Get user input
+    iPart = (long) d;
+    fPart = d - iPart;
+    return Math.abs(fPart);
+  }
+
+  public static void clear() {
+    if (cache != null) {
+      cache.clear();
+    }
+  }
+
+  public static void main(String[] args) throws Exception {
+    System.out.println("*** HGT position values and enhance elevation");
+    if (args.length == 3) {
+      HgtReader elevReader = new HgtReader(args[0]);
+      double lon = Double.parseDouble(args[1]);
+      double lat = Double.parseDouble(args[2]);
+      // check hgt direct
+      double elev = elevReader.getElevationFromHgt(lat, lon);
+      System.out.println("-----> elv for hgt " + lat + ", " + lon + " = " + elev);
+
+    }
+  }
+}
diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/PosUnifier.java b/brouter-map-creator/src/main/java/btools/mapcreator/PosUnifier.java
index bccbf7001..cea8cb5ad 100644
--- a/brouter-map-creator/src/main/java/btools/mapcreator/PosUnifier.java
+++ b/brouter-map-creator/src/main/java/btools/mapcreator/PosUnifier.java
@@ -7,7 +7,6 @@
 import java.io.FileInputStream;
 import java.io.InputStream;
 import java.util.HashMap;
-import java.util.Locale;
 import java.util.Map;
 
 import btools.util.CompactLongSet;
@@ -23,16 +22,21 @@
  * @author ab
  */
 public class PosUnifier extends MapCreatorBase {
+
+  public static final boolean UseRasterRd5FileName = false;
+
   private DiffCoderDataOutputStream nodesOutStream;
   private DiffCoderDataOutputStream borderNodesOut;
   private File nodeTilesOut;
+  private File outNodeFile;
   private CompactLongSet[] positionSets;
 
-  private Map<String, SrtmRaster> srtmmap;
+  private Map<String, ElevationRaster> srtmmap;
   private int lastSrtmLonIdx;
   private int lastSrtmLatIdx;
-  private SrtmRaster lastSrtmRaster;
+  private ElevationRaster lastSrtmRaster;
   private String srtmdir;
+  private String srtmfallbackdir;
 
   private CompactLongSet borderNids;
 
@@ -46,25 +50,40 @@ public static void main(String[] args) throws Exception {
       double lat = Double.parseDouble(args[2]);
 
       NodeData n = new NodeData(1, lon, lat);
-      SrtmRaster srtm = posu.hgtForNode(n.ilon, n.ilat);
       short selev = Short.MIN_VALUE;
+      ElevationRaster srtm = null;
+      /*
+      // check hgt direct
+      srtm = posu.hgtForNode(n.ilon, n.ilat);
+      if (srtm != null) {
+        selev = srtm.getElevation(n.ilon, n.ilat);
+      } else {
+        System.out.println("hgtForNode no data");
+      }
+      posu.resetElevationRaster();
+      System.out.println("-----> selv for hgt " + lat + ", " + lon + " = " + selev + " = " + (selev / 4.));
+      srtm = null;
+      selev = Short.MIN_VALUE;
+      */
       if (srtm == null) {
         srtm = posu.srtmForNode(n.ilon, n.ilat);
       }
       if (srtm != null) selev = srtm.getElevation(n.ilon, n.ilat);
-      posu.resetSrtm();
-      System.out.println("-----> selv for " + lat + ", " + lon + " = " + selev + " = " + (selev / 4.));
+      posu.resetElevationRaster();
+      System.out.println("-----> selv for bef " + lat + ", " + lon + " = " + selev + " = " + (selev / 4.));
       return;
-    } else if (args.length != 5) {
-      System.out.println("usage: java PosUnifier <node-tiles-in> <node-tiles-out> <bordernids-in> <bordernodes-out> <srtm-data-dir>");
+    } else if (args.length != 5 && args.length != 6) {
+      System.out.println("usage: java PosUnifier <node-tiles-in> <node-tiles-out> <bordernids-in> <bordernodes-out> <srtm-data-dir> [srtm-fallback-data-dir]");
+      System.out.println("or     java PosUnifier <srtm-data-dir> <lon> <lat>");
       return;
     }
-    new PosUnifier().process(new File(args[0]), new File(args[1]), new File(args[2]), new File(args[3]), args[4]);
+    new PosUnifier().process(new File(args[0]), new File(args[1]), new File(args[2]), new File(args[3]), args[4], (args.length == 6 ? args[5] : null));
   }
 
-  public void process(File nodeTilesIn, File nodeTilesOut, File bordernidsinfile, File bordernodesoutfile, String srtmdir) throws Exception {
+  public void process(File nodeTilesIn, File nodeTilesOut, File bordernidsinfile, File bordernodesoutfile, String srtmdir, String srtmfallbackdir) throws Exception {
     this.nodeTilesOut = nodeTilesOut;
     this.srtmdir = srtmdir;
+    this.srtmfallbackdir = srtmfallbackdir;
 
     // read border nids set
     DataInputStream dis = createInStream(bordernidsinfile);
@@ -88,9 +107,9 @@ public void process(File nodeTilesIn, File nodeTilesOut, File bordernidsinfile,
 
   @Override
   public void nodeFileStart(File nodefile) throws Exception {
-    resetSrtm();
-
-    nodesOutStream = createOutStream(fileFromTemplate(nodefile, nodeTilesOut, "u5d"));
+    resetElevationRaster();
+    outNodeFile = fileFromTemplate(nodefile, nodeTilesOut, "u5d");
+    nodesOutStream = createOutStream(outNodeFile);
 
     positionSets = new CompactLongSet[2500];
   }
@@ -106,7 +125,7 @@ public void nextNode(NodeData n) throws Exception {
       srtm = srtmForNode(n.ilon, n.ilat);
     } */
 
-    SrtmRaster srtm = srtmForNode(n.ilon, n.ilat);
+    ElevationRaster srtm = srtmForNode(n.ilon, n.ilat);
 
     if (srtm != null) n.selev = srtm.getElevation(n.ilon, n.ilat);
     findUniquePos(n);
@@ -120,7 +139,13 @@ public void nextNode(NodeData n) throws Exception {
   @Override
   public void nodeFileEnd(File nodeFile) throws Exception {
     nodesOutStream.close();
-    resetSrtm();
+    if (outNodeFile != null) {
+      if (lastSrtmRaster != null) {
+        String newName = outNodeFile.getAbsolutePath() + (lastSrtmRaster.nrows > 6001 ? "_1": "_3");
+        outNodeFile.renameTo(new File(newName));
+      }
+    }
+    resetElevationRaster();
   }
 
   private boolean checkAdd(int lon, int lat) {
@@ -168,7 +193,7 @@ private void _findUniquePos(NodeData n) {
    * get the srtm data set for a position srtm coords are
    * srtm_<srtmLon>_<srtmLat> where srtmLon = 180 + lon, srtmLat = 60 - lat
    */
-  private SrtmRaster srtmForNode(int ilon, int ilat) throws Exception {
+  private ElevationRaster srtmForNode(int ilon, int ilat) throws Exception {
     int srtmLonIdx = (ilon + 5000000) / 5000000;
     int srtmLatIdx = (654999999 - ilat) / 5000000 - 100; // ugly negative rounding...
 
@@ -178,35 +203,42 @@ private SrtmRaster srtmForNode(int ilon, int ilat) throws Exception {
     lastSrtmLonIdx = srtmLonIdx;
     lastSrtmLatIdx = srtmLatIdx;
 
-    String slonidx = "0" + srtmLonIdx;
-    String slatidx = "0" + srtmLatIdx;
-    String filename = "srtm_" + slonidx.substring(slonidx.length() - 2) + "_" + slatidx.substring(slatidx.length() - 2);
+    String filename;
+    if (UseRasterRd5FileName) {
+      filename = genFilenameRd5(ilon, ilat);
+    } else {
+      filename = genFilenameXY(srtmLonIdx, srtmLatIdx);
+    }
 
     lastSrtmRaster = srtmmap.get(filename);
     if (lastSrtmRaster == null && !srtmmap.containsKey(filename)) {
       File f = new File(new File(srtmdir), filename + ".bef");
       if (f.exists()) {
-        System.out.println("*** reading: " + f);
         try {
           InputStream isc = new BufferedInputStream(new FileInputStream(f));
-          lastSrtmRaster = new RasterCoder().decodeRaster(isc);
+          lastSrtmRaster = new ElevationRasterCoder().decodeRaster(isc);
           isc.close();
         } catch (Exception e) {
           System.out.println("**** ERROR reading " + f + " ****");
         }
+        System.out.println("*** reading: " + f + "  " + lastSrtmRaster.ncols);
         srtmmap.put(filename, lastSrtmRaster);
         return lastSrtmRaster;
       }
-
-      f = new File(new File(srtmdir), filename + ".zip");
-      // System.out.println("reading: " + f + " ilon=" + ilon + " ilat=" + ilat);
-      if (f.exists()) {
-        try {
-          lastSrtmRaster = new SrtmData(f).getRaster();
+      if (srtmfallbackdir != null) {
+        f = new File(new File(srtmfallbackdir), filename + ".bef");
+        if (f.exists()) {
+          try {
+            InputStream isc = new BufferedInputStream(new FileInputStream(f));
+            //lastSrtmRaster = new StatRasterCoder().decodeRaster(isc);
+            lastSrtmRaster = new ElevationRasterCoder().decodeRaster(isc);
+            isc.close();
+          } catch (Exception e) {
+            System.out.println("**** ERROR reading " + f + " ****");
+          }
+          System.out.println("*** reading: " + f + "  " + lastSrtmRaster.cellsize);
           srtmmap.put(filename, lastSrtmRaster);
           return lastSrtmRaster;
-        } catch (Exception e) {
-          System.out.println("**** ERROR reading " + f + " ****");
         }
       }
       srtmmap.put(filename, lastSrtmRaster);
@@ -214,23 +246,41 @@ private SrtmRaster srtmForNode(int ilon, int ilat) throws Exception {
     return lastSrtmRaster;
   }
 
-  private SrtmRaster hgtForNode(int ilon, int ilat) throws Exception {
+  static String genFilenameXY(int srtmLonIdx, int srtmLatIdx) {
+    String slonidx = "0" + srtmLonIdx;
+    String slatidx = "0" + srtmLatIdx;
+    return "srtm_" + slonidx.substring(slonidx.length() - 2) + "_" + slatidx.substring(slatidx.length() - 2);
+  }
+
+  static String genFilenameRd5(int ilon, int ilat) {
+    int lonDegree = ilon / 1000000;
+    int latDegree = ilat / 1000000;
+    int lonMod5 = lonDegree % 5;
+    int latMod5 = latDegree % 5;
+    lonDegree = lonDegree - 180 - lonMod5;
+    latDegree = latDegree - 90 - latMod5;
+    return String.format("srtm_%s_%s", lonDegree < 0 ? "W" + (-lonDegree) : "E" + lonDegree,
+      latDegree < 0 ? "S" + (-latDegree) : "N" + latDegree);
+  }
+
+
+  private ElevationRaster hgtForNode(int ilon, int ilat) throws Exception {
     double lon = (ilon - 180000000) / 1000000.;
     double lat = (ilat - 90000000) / 1000000.;
 
     String filename = buildHgtFilename(lat, lon);
     // don't block lastSrtmRaster
-    SrtmRaster srtm = srtmmap.get(filename);
+    ElevationRaster srtm = srtmmap.get(filename);
     if (srtm == null) {
-      File f = new File(new File(srtmdir), filename + ".hgt");
+      File f = new File(new File(srtmdir), filename + ".zip");
       if (f.exists()) {
-        srtm = new ConvertLidarTile().getRaster(f, lon, lat);
+        srtm = new ElevationRasterTileConverter().getRaster(f, lon, lat);
         srtmmap.put(filename, srtm);
         return srtm;
       }
-      f = new File(new File(srtmdir), filename + ".zip");
+      f = new File(new File(srtmdir), filename + ".hgt");
       if (f.exists()) {
-        srtm = new ConvertLidarTile().getRaster(f, lon, lat);
+        srtm = new ElevationRasterTileConverter().getRaster(f, lon, lat);
         srtmmap.put(filename, srtm);
         return srtm;
       }
@@ -238,6 +288,7 @@ private SrtmRaster hgtForNode(int ilon, int ilat) throws Exception {
     return srtm;
   }
 
+
   private String buildHgtFilename(double llat, double llon) {
     int lat = (int) llat;
     int lon = (int) llon;
@@ -253,10 +304,10 @@ private String buildHgtFilename(double llat, double llon) {
       lon = -lon + 1;
     }
 
-    return String.format(Locale.US, "%s%02d%s%03d", latPref, lat, lonPref, lon);
+    return String.format("%s%02d%s%03d", latPref, lat, lonPref, lon);
   }
 
-  private void resetSrtm() {
+  private void resetElevationRaster() {
     srtmmap = new HashMap<>();
     lastSrtmLonIdx = -1;
     lastSrtmLatIdx = -1;
diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/SrtmData.java b/brouter-map-creator/src/main/java/btools/mapcreator/SrtmData.java
deleted file mode 100644
index b101cd889..000000000
--- a/brouter-map-creator/src/main/java/btools/mapcreator/SrtmData.java
+++ /dev/null
@@ -1,166 +0,0 @@
-package btools.mapcreator;
-
-/**
- * This is a wrapper for a 5*5 degree srtm file in ascii/zip-format
- * <p>
- * - filter out unused nodes according to the way file
- * - enhance with SRTM elevation data
- * - split further in smaller (5*5 degree) tiles
- *
- * @author ab
- */
-
-import java.io.BufferedInputStream;
-import java.io.BufferedOutputStream;
-import java.io.BufferedReader;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.io.OutputStream;
-import java.util.StringTokenizer;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipInputStream;
-
-public class SrtmData {
-  private SrtmRaster raster;
-
-  public SrtmData(File file) throws Exception {
-    raster = new SrtmRaster();
-
-    ZipInputStream zis = new ZipInputStream(new BufferedInputStream(new FileInputStream(file)));
-    try {
-      for (; ; ) {
-        ZipEntry ze = zis.getNextEntry();
-        if (ze.getName().endsWith(".asc")) {
-          readFromStream(zis);
-          return;
-        }
-      }
-    } finally {
-      zis.close();
-    }
-  }
-
-  public SrtmRaster getRaster() {
-    return raster;
-  }
-
-  private String secondToken(String s) {
-    StringTokenizer tk = new StringTokenizer(s, " ");
-    tk.nextToken();
-    return tk.nextToken();
-  }
-
-  public void readFromStream(InputStream is) throws Exception {
-    BufferedReader br = new BufferedReader(new InputStreamReader(is));
-    int linenr = 0;
-    for (; ; ) {
-      linenr++;
-      if (linenr <= 6) {
-        String line = br.readLine();
-        if (linenr == 1)
-          raster.ncols = Integer.parseInt(secondToken(line));
-        else if (linenr == 2)
-          raster.nrows = Integer.parseInt(secondToken(line));
-        else if (linenr == 3)
-          raster.xllcorner = Double.parseDouble(secondToken(line));
-        else if (linenr == 4)
-          raster.yllcorner = Double.parseDouble(secondToken(line));
-        else if (linenr == 5)
-          raster.cellsize = Double.parseDouble(secondToken(line));
-        else if (linenr == 6) {
-          // nodata ignored here ( < -250 assumed nodata... )
-          // raster.noDataValue = Short.parseShort( secondToken( line ) );
-          raster.eval_array = new short[raster.ncols * raster.nrows];
-        }
-      } else {
-        int row = 0;
-        int col = 0;
-        int n = 0;
-        boolean negative = false;
-        for (; ; ) {
-          int c = br.read();
-          if (c < 0)
-            break;
-          if (c == ' ') {
-            if (negative)
-              n = -n;
-            short val = n < -250 ? Short.MIN_VALUE : (short) (n);
-
-            raster.eval_array[row * raster.ncols + col] = val;
-            if (++col == raster.ncols) {
-              col = 0;
-              ++row;
-            }
-            n = 0;
-            negative = false;
-          } else if (c >= '0' && c <= '9') {
-            n = 10 * n + (c - '0');
-          } else if (c == '-') {
-            negative = true;
-          }
-        }
-        break;
-      }
-    }
-    br.close();
-  }
-
-  public static void main(String[] args) throws Exception {
-    String fromDir = args[0];
-    String toDir = args[1];
-
-    File[] files = new File(fromDir).listFiles();
-    for (File f : files) {
-      if (!f.getName().endsWith(".zip")) {
-        continue;
-      }
-      System.out.println("*** reading: " + f);
-      long t0 = System.currentTimeMillis();
-      SrtmRaster raster = new SrtmData(f).getRaster();
-      long t1 = System.currentTimeMillis();
-      String name = f.getName();
-
-      long zipTime = t1 - t0;
-
-      File fbef = new File(new File(toDir), name.substring(0, name.length() - 3) + "bef");
-      System.out.println("recoding: " + f + " to " + fbef);
-      OutputStream osbef = new BufferedOutputStream(new FileOutputStream(fbef));
-      new RasterCoder().encodeRaster(raster, osbef);
-      osbef.close();
-
-      System.out.println("*** re-reading: " + fbef);
-
-      long t2 = System.currentTimeMillis();
-      InputStream isc = new BufferedInputStream(new FileInputStream(fbef));
-      SrtmRaster raster2 = new RasterCoder().decodeRaster(isc);
-      isc.close();
-      long t3 = System.currentTimeMillis();
-
-      long befTime = t3 - t2;
-
-      System.out.println("*** zip-time: " + zipTime + "*** bef-time: " + befTime);
-
-      String s1 = raster.toString();
-      String s2 = raster2.toString();
-
-      if (!s1.equals(s2)) {
-        throw new IllegalArgumentException("missmatch: " + s1 + "<--->" + s2);
-      }
-
-      int cols = raster.ncols;
-      int rows = raster.nrows;
-      for (int c = 0; c < cols; c++) {
-        for (int r = 0; r < rows; r++) {
-          int idx = r * cols + c;
-
-          if (raster.eval_array[idx] != raster2.eval_array[idx]) {
-            throw new IllegalArgumentException("missmatch: at " + c + "," + r + ": " + raster.eval_array[idx] + "<--->" + raster2.eval_array[idx]);
-          }
-        }
-      }
-    }
-  }
-}
diff --git a/brouter-map-creator/src/main/java/btools/mapcreator/WayLinker.java b/brouter-map-creator/src/main/java/btools/mapcreator/WayLinker.java
index 91c70a969..0a01b9328 100644
--- a/brouter-map-creator/src/main/java/btools/mapcreator/WayLinker.java
+++ b/brouter-map-creator/src/main/java/btools/mapcreator/WayLinker.java
@@ -51,6 +51,7 @@ public class WayLinker extends MapCreatorBase implements Runnable {
   private short lookupMinorVersion;
 
   private long creationTimeStamp;
+  private byte elevationType;
 
   private BExpressionContextWay expctxWay;
 
@@ -217,7 +218,14 @@ public boolean wayFileStart(File wayfile) throws Exception {
     File trafficFile = fileFromTemplate(wayfile, trafficTilesIn, "trf");
 
     // process corresponding node-file, if any
-    File nodeFile = fileFromTemplate(wayfile, nodeTilesIn, "u5d");
+    elevationType = 3;
+    File nodeFile = fileFromTemplate(wayfile, nodeTilesIn, "u5d_1");
+    if (nodeFile.exists()) {
+      elevationType = 1;
+    } else {
+      nodeFile = fileFromTemplate(wayfile, nodeTilesIn, "u5d_3");
+      if (!nodeFile.exists()) nodeFile = fileFromTemplate(wayfile, nodeTilesIn, "u5d");
+    }
     if (nodeFile.exists()) {
       reset();
 
@@ -539,6 +547,7 @@ public void wayFileEnd(File wayfile) throws Exception {
       for (int i55 = 0; i55 < 25; i55++) {
         os.writeInt(fileHeaderCrcs[i55]);
       }
+      os.writeByte(elevationType);
 
       os.close();
 
diff --git a/brouter-map-creator/src/test/java/btools/mapcreator/MapcreatorTest.java b/brouter-map-creator/src/test/java/btools/mapcreator/MapcreatorTest.java
index beb4cbd33..b509bffa2 100644
--- a/brouter-map-creator/src/test/java/btools/mapcreator/MapcreatorTest.java
+++ b/brouter-map-creator/src/test/java/btools/mapcreator/MapcreatorTest.java
@@ -42,7 +42,7 @@ public void mapcreatorTest() throws Exception {
     File unodes55 = new File(tmpdir, "unodes55");
     File bordernodes = new File(tmpdir, "bordernodes.dat");
     unodes55.mkdir();
-    new PosUnifier().process(nodes55, unodes55, borderFile, bordernodes, workingDir.getAbsolutePath());
+    new PosUnifier().process(nodes55, unodes55, borderFile, bordernodes, workingDir.getAbsolutePath(), null);
 
     // run WayLinker
     File segments = new File(tmpdir, "segments");
diff --git a/brouter-mapaccess/src/main/java/btools/mapaccess/NodesCache.java b/brouter-mapaccess/src/main/java/btools/mapaccess/NodesCache.java
index f2a63160d..e16b8d264 100644
--- a/brouter-mapaccess/src/main/java/btools/mapaccess/NodesCache.java
+++ b/brouter-mapaccess/src/main/java/btools/mapaccess/NodesCache.java
@@ -385,4 +385,20 @@ public void close() {
       }
     }
   }
+
+  public int getElevationType(int ilon, int ilat) {
+    int lonDegree = ilon / 1000000;
+    int latDegree = ilat / 1000000;
+    OsmFile[] fileRow = fileRows[latDegree];
+    int ndegrees = fileRow == null ? 0 : fileRow.length;
+    for (int i = 0; i < ndegrees; i++) {
+      if (fileRow[i].lonDegree == lonDegree) {
+        OsmFile osmf = fileRow[i];
+        if (osmf != null) return osmf.elevationType;
+        break;
+      }
+    }
+    return 3;
+  }
+
 }
diff --git a/brouter-mapaccess/src/main/java/btools/mapaccess/OsmFile.java b/brouter-mapaccess/src/main/java/btools/mapaccess/OsmFile.java
index 0f773cf20..67eff299f 100644
--- a/brouter-mapaccess/src/main/java/btools/mapaccess/OsmFile.java
+++ b/brouter-mapaccess/src/main/java/btools/mapaccess/OsmFile.java
@@ -33,6 +33,7 @@ final class OsmFile {
   private int cellsize;
   private int ncaches;
   private int indexsize;
+  protected byte elevationType = 3;
 
   public OsmFile(PhysicalFile rafile, int lonDegree, int latDegree, DataBuffers dataBuffers) throws IOException {
     this.lonDegree = lonDegree;
@@ -43,6 +44,7 @@ public OsmFile(PhysicalFile rafile, int lonDegree, int latDegree, DataBuffers da
 
     if (rafile != null) {
       divisor = rafile.divisor;
+      elevationType = rafile.elevationType;
 
       cellsize = 1000000 / divisor;
       ncaches = divisor * divisor;
diff --git a/brouter-mapaccess/src/main/java/btools/mapaccess/PhysicalFile.java b/brouter-mapaccess/src/main/java/btools/mapaccess/PhysicalFile.java
index 2c2a18620..e61f46965 100644
--- a/brouter-mapaccess/src/main/java/btools/mapaccess/PhysicalFile.java
+++ b/brouter-mapaccess/src/main/java/btools/mapaccess/PhysicalFile.java
@@ -24,6 +24,7 @@ final public class PhysicalFile {
   String fileName;
 
   public int divisor = 80;
+  public byte elevationType = 3;
 
   public static void main(String[] args) {
     MicroCache.debug = true;
@@ -113,6 +114,10 @@ public PhysicalFile(File f, DataBuffers dataBuffers, int lookupVersion, int look
 
     if (len == pos) return; // old format o.k.
 
+    if ((len-pos) > extraLen) {
+      extraLen++;
+    }
+
     if (len < pos + extraLen) { // > is o.k. for future extensions!
       throw new IOException("file of size " + len + " too short, should be " + (pos + extraLen));
     }
@@ -134,5 +139,8 @@ public PhysicalFile(File f, DataBuffers dataBuffers, int lookupVersion, int look
     for (int i = 0; i < 25; i++) {
       fileHeaderCrcs[i] = dis.readInt();
     }
+    try {
+      elevationType = dis.readByte();
+    } catch (Exception e) {}
   }
 }
diff --git a/docs/developers/build_segments.md b/docs/developers/build_segments.md
index 513fab5a0..79bd2967b 100644
--- a/docs/developers/build_segments.md
+++ b/docs/developers/build_segments.md
@@ -26,7 +26,7 @@ official BRouter segments files are the ones provided by
 [CGIAR](https://cgiarcsi.community/data/srtm-90m-digital-elevation-database-v4-1/).
 If you are working with rather small geographical extracts, you can download
 tiles manually using [this
-interface](http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp) (use the
+interface](https://srtm.csi.cgiar.org/srtmdata/) (use the
 "ArcInfo ASCII" format), instead of having to ask for an access for bulk
 download of data. There is no need to unzip the downloaded files, the
 `process_pbf_planet.sh` script expects a folder with all the ZIP files inside
@@ -48,3 +48,37 @@ and set the `PLANET_FILE` variable to point to it.
 _Note:_ It is possible that you encounter an error complaining about not being
 able to run `bash^M` on Linux/Mac OS. You can fix this one by running
 `sed -i -e 's/\r$//' process_pbf_planet.sh`.
+
+
+## Run a generation for elevation data tiles
+
+To match the 5x5 OSM data grid (*.rd5) files from BRouter, there are elevation
+data in a 5x5 degree format (*.bef). At the moment (end of 2023) the naming of
+this elevation tiles follows the konvention used by srtm.csi.cgiar.org: srtm_x_y
+
+As the srtm files are only available between 60N and 60S the filenames above 60N
+contains negative values. e.g. srtm_34_-1 as a tile above srtm_34_00.
+
+Please see OSM wiki for more info on [srtm](https://wiki.openstreetmap.org/wiki/SRTM).
+
+The converter generates bef tiles from `hgt` files, `zipped hgt` files and `zipped 'ESRI' asc` files.
+
+Converter call with arguments for a single tile generation:
+
+`ElevationRasterTileConverter <srtm-filename | all> <hgt-data-dir> <srtm-output-dir> [arc seconds (1 or 3,default=3)] [hgt-fallback-data-dir]
+Samples:
+$ ... ElevationRasterTileConverter srtm_34_-1 ./srtm/hgt3sec ./srtm/srtm3_bef
+$ ... ElevationRasterTileConverter srtm_34_-1 ./srtm/hgt1sec ./srtm/srtm1_bef 1
+$ ... ElevationRasterTileConverter srtm_34_-1 ./srtm/hgt1sec ./srtm/srtm1_bef 1 ./srtm/hgt3sec
+`
+Arguments for multi file generation (world wide):
+
+`$ ... ElevationRasterTileConverter all ./srtm/hgt3sec ./srtm/srtm3_bef
+$ ... ElevationRasterTileConverter all ./srtm/hgt1sec ./srtm/srtm1_bef 1
+$ ... ElevationRasterTileConverter all ./srtm/hgt1sec ./srtm/srtm1_bef 1 ./srtm/hgt3sec
+`
+
+To use 1sec and 3sec bef tiles at rd5 generation time you need an extra parameter to the fallback folder.
+E.g.
+`$ ... PosUnifier nodes55 unodes55 bordernids.dat bordernodes.dat ../srtm/srtm1_bef ../srtm/srtm3_bef
+`