SNAP gpt |

# The SNAP Graph Processing Tool (gpt)

        Usage:
          gpt <op>|<graph-file> [options] [<source-file-1> <source-file-2> ...]

        Description:
          This tool is used to execute SNAP raster data operators in batch-mode. The
          operators can be used stand-alone or combined as a directed acyclic graph
          (DAG). Processing graphs are represented using XML. More info about
          processing graphs, the operator API, and the graph XML format can be found
          in the SNAP documentation.

        Arguments:
          <op>               Name of an operator. See below for the list of <op>s.
          <graph-file>       Operator graph file (XML format).
          <source-file-i>    The <i>th source product file. The actual number of source
                             file arguments is specified by <op>. May be optional for
                             operators which use the -S option.

        Options:
          -h                 Displays command usage. If <op> is given, the specific
                             operator usage is displayed.
          -e                 Displays more detailed error messages. Displays a stack
                             trace, if an exception occurs.
          -t <file>          The target file. Default value is './target.dim'.
          -f <format>        Output file format, e.g. 'GeoTIFF', 'HDF5',
                             'BEAM-DIMAP'. If not specified, format will be derived
                             from the target filename extension, if any, otherwise the
                             default format is 'BEAM-DIMAP'. Ony used, if the graph
                             in <graph-file> does not specify its own 'Write' operator.
          -p <file>          A (Java Properties) file containing processing
                             parameters in the form <name>=<value> or a XML file
                             containing a a parameter DOM for the operator. Entries in this
                             file are overwritten by the -P<name>=<value> command-line
                             option (see below). The following variables are substituted in
                             the parameters file:
                                 ${gpt.operator} (given by the 'op' argument)
                                 ${gpt.graphFile} (given by the 'graph-file' argument)
                                 ${gpt.parametersFile} (given by the -p option)
                                 ${gpt.targetFile} (given by the -t option)
                                 ${gpt.targetFormat} (given by the -f option)
          -c <cache-size>    Sets the tile cache size in bytes. Value can be suffixed
                             with 'K', 'M' and 'G'. Must be less than maximum
                             available heap space. If equal to or less than zero, tile
                             caching will be completely disabled. The default tile
                             cache size is '512M'.
          -q <parallelism>   Sets the maximum parallelism used for the computation, i.e.
                             the maximum number of parallel (native) threads.
                             The default parallelism is '8'.
          -x                 Clears the internal tile cache after writing a complete
                             row of tiles to the target product file. This option may
                             be useful if you run into memory problems.
          -T<target>=<file>  Defines a target product. Valid for graphs only. <target>
                             must be the identifier of a node in the graph. The node's
                             output will be written to <file>.
          -S<source>=<file>  Defines a source product. <source> is specified by the
                             operator or the graph. In an XML graph, all occurrences of
                             ${<source>} will be replaced with references to a source
                             product located at <file>.
          -P<name>=<value>   Defines a processing parameter, <name> is specific for the
                             used operator or graph. In an XML graph, all occurrences of
                             ${<name>} will be replaced with <value>. Overwrites
                             parameter values specified by the '-p' option.
          -D<name>=<value>   Defines a system property for this invocation.
          -v <dir>           A directory containing any number of Velocity templates.
                             Each template generates a text output file along with the
                             target product. This feature has been added to support a
                             flexible generation of metadata files.
                             See http://velocity.apache.org/ and option -m.
          -m <file>          A (Java Properties) file containing (constant) metadata
                             in the form <name>=<value> or any XML file. Its primary
                             usage is to provide an additional context to be used
                             from within the Velocity templates. See option -v.
          --diag             Displays version and diagnostic information.

        Operators:
          AddElevation                     Creates a DEM band
          AddLandCover                     Creates a land cover band
          BandMaths                        Create a product with one or more bands using mathematical expressions.
          Binning                          Performs spatial and temporal aggregation of pixel values into cells ('bins') of a planetary grid
          Collocate                        Collocates two products based on their geo-codings.
          Convert-Datatype                 Convert product data type
          EMClusterAnalysis                Performs an expectation-maximization (EM) cluster analysis.
          Fill-DEM-Hole                    Fill holes in given DEM product file.
          Flip                             flips a product horizontal/vertical
          GLCM                             Extract Texture Features
          Image-Filter                     Common Image Processing Filters
          Import-Vector                    Imports a shape file into a product
          KDTree-KNN-Classifier            KDTree KNN classifier
          KMeansClusterAnalysis            Performs a K-Means cluster analysis.
          KNN-Classifier                   K-Nearest Neighbour classifier
          Land-Cover-Mask                  Perform decision tree classification
          Land-Sea-Mask                    Creates a bitmask defining land vs ocean.
          LandWaterMask                    Operator creating a target product with a single band containing a land/water-mask.
          LinearToFromdB                   Converts bands to/from dB
          Maximum-Likelihood-Classifier    Maximum Likelihood classifier
          Merge                            Allows copying raster data from any number of source products to a specified 'master' product.
          Minimum-Distance-Classifier      Minimum Distance classifier
          Mosaic                           Creates a mosaic out of a set of source products.
          NdviOp                           The retrieves the Normalized Difference Vegetation Index (NDVI).
          PCA                              Performs a Principal Component Analysis.
          PixEx                            Extracts pixels from given locations and source products.
          ProductSet-Reader                Adds a list of sources
          Random-Forest-Classifier         Random Forest based classifier
          Read                             Reads a data product from a given file location.
          ReplaceMetadata                  Replace the metadata of the first product with that of the second
          Reproject                        Reprojection of a source product to a target Coordinate Reference System.
          Resample                         Resampling of a multi-size source product to a single-size target product.
          StatisticsOp                     Computes statistics for an arbitrary number of source products.
          Subset                           Create a spatial and/or spectral subset of a data product.
          TemporalPercentile               Computes percentiles over a given time period.
          Terrain-Mask                     Terrain Mask Generation
          ToolAdapterOp                    Tool Adapter Operator
          Unmix                            Performs a linear spectral unmixing.
          Write                            Writes a data product to a file.