diff --git a/doc/apps/ground.rst b/doc/apps/ground.rst
index 526acfc057..66830b5520 100644
--- a/doc/apps/ground.rst
+++ b/doc/apps/ground.rst
@@ -5,7 +5,7 @@ ground
 ********************************************************************************
 
 The ``ground`` command is used to segment the input point cloud into ground
-versus non-ground returns.
+versus non-ground returns using :ref:`filters.smrf` and :ref:`filters.outlier`.
 
 ::
 
@@ -13,17 +13,20 @@ versus non-ground returns.
 
 ::
 
-    --input, -i         Input filename
-    --output, -o        Output filename
-    --max_window_size   Max window size
-    --slope             Slope
-    --max_distance      Max distance
-    --initial_distance  Initial distance
-    --cell_size         Cell size
-    --classify          Apply classification labels?
-    --extract           Extract ground returns?
-    --approximate, -a   Use approximate algorithm? (much faster)
-    --reset             Reset classification prior to segmentation.
-    --denoise           Apply statistical outlier removal prior to segmentation.
-
-  For more information, see the full documentation for PDAL at http://pdal.io/
+  --input, -i         Input filename
+  --output, -o        Output filename
+  --max_window_size   Max window size
+  --slope             Slope
+  --max_distance      Max distance
+  --initial_distance  Initial distance
+  --cell_size         Cell size
+  --extract           Extract ground returns?
+  --reset             Reset classifications prior to segmenting?
+  --denoise           Apply statistical outlier removal prior to segmenting?
+  --returns           Include last returns?
+  --scalar            Elevation scalar?
+  --threshold         Elevation threshold?
+  --cut               Cut net size?
+  --ignore            A range query to ignore when processing
+
+
diff --git a/kernels/GroundKernel.cpp b/kernels/GroundKernel.cpp
index a5830e7a9a..4ad6911bdc 100644
--- a/kernels/GroundKernel.cpp
+++ b/kernels/GroundKernel.cpp
@@ -73,14 +73,20 @@ void GroundKernel::addSwitches(ProgramArgs& args)
 {
     args.add("input,i", "Input filename", m_inputFile).setPositional();
     args.add("output,o", "Output filename", m_outputFile).setPositional();
-    args.add("max_window_size", "Max window size", m_maxWindowSize, 33.0);
-    args.add("slope", "Slope", m_slope, 1.0);
+    args.add("max_window_size", "Max window size", m_maxWindowSize, 18.0);
+    args.add("slope", "Slope", m_slope, 0.15);
     args.add("max_distance", "Max distance", m_maxDistance, 2.5);
     args.add("initial_distance", "Initial distance", m_initialDistance, .15);
     args.add("cell_size", "Cell size", m_cellSize, 1.0);
     args.add("extract", "Extract ground returns?", m_extract);
     args.add("reset", "Reset classifications prior to segmenting?", m_reset);
     args.add("denoise", "Apply statistical outlier removal prior to segmenting?", m_denoise);
+    args.add("returns", "Include last returns?", m_returns,
+             {"last", "only"});
+    args.add("scalar", "Elevation scalar?", m_scalar, 1.25);
+    args.add("threshold", "Elevation threshold?", m_threshold, 0.5);
+    args.add("cut", "Cut net size?", m_cut, 0.0);
+    args.add("ignore", "A range query to ignore when processing", m_ignored);
 }
 
 int GroundKernel::execute()
@@ -93,12 +99,16 @@ int GroundKernel::execute()
     Options outlierOptions;
 
     Options groundOptions;
-    groundOptions.add("max_window_size", m_maxWindowSize);
+    groundOptions.add("window", m_maxWindowSize);
+    groundOptions.add("threshold", m_threshold);
     groundOptions.add("slope", m_slope);
-    groundOptions.add("max_distance", m_maxDistance);
-    groundOptions.add("initial_distance", m_initialDistance);
-    groundOptions.add("cell_size", m_cellSize);
-    groundOptions.add("ignore", "Classification[7:7]");
+    groundOptions.add("cell", m_cellSize);
+    groundOptions.add("cut", m_cut);
+    groundOptions.add("scalar", m_scalar);
+    for (auto& s: m_returns)
+        groundOptions.add("returns", s);
+    for(DimRange& r: m_ignored)
+        groundOptions.add("ignore", r);
 
     Options rangeOptions;
     rangeOptions.add("limits", "Classification[2:2]");
@@ -113,7 +123,8 @@ int GroundKernel::execute()
     if (m_denoise)
         outlierStage = &makeFilter("filters.outlier", *assignStage, outlierOptions);
 
-    Stage& groundStage = makeFilter("filters.pmf", *outlierStage, groundOptions);
+    Stage& groundStage = makeFilter("filters.smrf", *outlierStage, groundOptions);
+
 
     Stage* rangeStage = &groundStage;
     if (m_extract)
diff --git a/kernels/GroundKernel.hpp b/kernels/GroundKernel.hpp
index 9db31ecd48..c824d37d74 100644
--- a/kernels/GroundKernel.hpp
+++ b/kernels/GroundKernel.hpp
@@ -38,7 +38,7 @@
 #include <pdal/Kernel.hpp>
 #include <pdal/pdal_export.hpp>
 #include <pdal/util/FileUtils.hpp>
-
+#include "../filters/private/DimRange.hpp"
 #include <memory>
 #include <string>
 
@@ -60,6 +60,7 @@ class PDAL_DLL GroundKernel : public Kernel
 
     std::string m_inputFile;
     std::string m_outputFile;
+    std::string m_ignore;
     double m_maxWindowSize;
     double m_slope;
     double m_maxDistance;
@@ -68,6 +69,13 @@ class PDAL_DLL GroundKernel : public Kernel
     bool m_extract;
     bool m_reset;
     bool m_denoise;
+    StringList m_returns;
+    double m_scalar;
+    double m_threshold;
+    double m_cut;
+    std::string m_dir;
+    std::vector<DimRange> m_ignored;
+
 };
 
 } // namespace pdal