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Raster checks

Jiří Kadlec edited this page Apr 28, 2020 · 26 revisions

Raster checks

Delivery can be unzipped

The check can not be skipped. The result values of the check are: ok, aborted.

A delivery must be uploaded to QC tool as a ZIP file.

File names match file naming conventions

The check can not be skipped. The result values of the check are: ok, aborted.

The number of .tif files in the delivery must be equal to the number of layers in the product naming convention. Each .tif file must be a GeoTiff raster with a single band.

Inside one delivery, files can be located anywhere in the directory hierarchy, eg. all examples are valid: FTY_2015_020m_eu_03035_d04.tif, fty_020m/fty_2015_020m_eu_03035_d04.tif, 2015/fty/20m/fty_2015_020m_eu_03035_d04.tif.

The required file naming convention for all products is:

<product_code>_<reference_year>_<resolution>_<aoi_code>_<epsg_code>_<version>.tif

where:

  • product_code is 3-letter code of the product, e.g. FTY, GRA, WAW, IMC, IMD, TCD;
  • reference_year is 4-digit reference year, e.g. 2015;
  • resolution is raster cell size in meters, e.g. 010m, 020m or 100m;
  • aoi_code is 2-letter country code or AOI code, e.g. eu;
  • epsg_code is a valid EPSG code identifying the raster coordinate reference system, e.g. 3035;
  • version is product specific version identifier.

Metadata are in accord with INSPIRE specification

A raster product delivery must contain a valid INSPIRE compliant XML metadata file and INSPIRE mapping tables.

INSPIRE mapping tables show the evidence that the products delivered are compatible with the INSPIRE Data Specification on Land Cover. This evidence is provided as table document showing the associations between the source (product/deliverable) and the target data model (INSPIRE Data Specification on Land Cover). Mapping tables are provided together with the final products.

Attribute table is composed of prescribed attributes

Each HRL raster delivery must have a .tif.vat.dbf file with a raster attribute table. Only attribute names are checked. The attribute names are case insensitive. The attribute table must always have the following attributes:

  • value, corresponds to unique codes in the GeoTiff file
  • count, corresponds to the number of raster cells belonging to each code.
  • area_km2, the area in square kilometres covered by cells with the code.
  • area_perc, the area in square kilometres covered by cells with the code, expressed as percent of total mapped area.
  • class_name, a text description of the land use / landcover class corresponding to the code.

Raster uses specific EPSG code

The EPSG authority must be part of the GeoTiff file's spatial reference system information. The only accepted EPSG code is EPSG:3035 (ETRS89 ETRS-LAEA equal-area projection). The EPSG code must be explicitly included in the CRS definition.

Pixel has specific size

All cells in the raster product must have the same cell size. Required cell size is specified by the cellsize parameter in each product definition.

Bounding box upper left corner is positioned on grid

  • Upper-left X, Y coordinates of the raster must be divisible by raster cell size with no remainder;
  • Upper-left X, Y coordinates of the raster must be divisible by 1000 with no remainder.

Raster datatype is of specific bit depth

The GeoTiff file in the raster delivery must conform to required data type. The required data type is Byte (values from 0 to 255) or Int16 (values from -32768 to +32767)

Raster uses specific compression formats

A raster delivery must have a compression type specified. The compression type of the GeoTiff file must be LZW.

Pixels have specific values

See dedicated page Raster values.

There is no gap in the AOI

The AOI is defined by the boundary package, see Boundaries. There must be no cell having the value set to NoData inside the AOI. If gaps are found, the raster.gap check creates a raster attachment file with all gaps inside the AOI set to 1. If the number of detected gaps is < 1,000,000 pixels, then an additional vector attachment file with vector boundaries of gap areas is also provided.

The GeoTiff raster file is stored in tiled format

The data inside the GeoTiff raster file must be stored in tiles. The number of rows and columns in one tile must not be greater than the max_blocksize setting. Recommended tile size is 256 x 256 or 512 x 512 pixels. For more detail about tiled GeoTiff format, see the Cloud-Optimized GeoTiff specification (https://www.cogeo.org/).

Minimum mapping unit

See dedicated page Raster MMU.

Color table is in accord with specification

Each raster delivery GeoTiff file must have a colour table. The colour table must be embedded in the GeoTiff file and provided in form of a tif.clr text file which is part of the delivery. Values in the GeoTiff colour table and in the .tif.clr colour table must match.

For product-specific colour table values see dedicated page Raster colour table.

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