Usage

Configuration

Usage of the ERS_NRB package currently relies on a configuration file that needs to be set up by the user. The configuration file follows the INI format, which uses plain text to store properties as key-value pairs. INI files can be created and opened with any text editor. An example config.ini file for the ERS_NRB package can be found here:

https://github.com/SAR-ARD/ERS_NRB/blob/main/config.ini

The following provides an overview of the parameters the config.ini should contain and anything that should be considered when selecting their values:

  • mode

Options: all | nrb | snap

This parameter determines if the entire processing chain should be executed or only part of it.

  • aoi_geometry

The area of interest (AOI) for which ERS-NRB products should be created, it needs to be a geojson.

  • mindate & maxdate

The time period to create ERS-NRB products for. Allowed date formats are %Y-%m-%d and %Y-%m-%dT%H:%M:%S.

  • acq_mode

Options: IMP | IMM | APP

The acquisition mode of the source scenes that should be processed.

  • work_dir & scene_dir

Both need to be provided as full paths to existing directories. work_dir is the main directory in which any subdirectories and files are stored that are generated during processing. scene_dir will be searched recursively for any ASAR/ERS scenes using the regex pattern '^SAR.*\.E[12]$' and '^ASA.*\.N1$'.

  • tmp_dir, dem_dir & **wbm_dir*

Processing ERS-NRB products creates many intermediate files that are expected to be stored in separate subdirectories. The default values provided in the example configuration file linked above are recommended and will automatically create subdirectories relative to the directory specified with work_dir. E.g., dem_dir = DEM will create the subdirectory /<work_dir>/DEM. Optionally, full paths to existing directories can be provided for all of these parameters.

  • db_file

Any ASAR/ERS scenes found in scene_dir will be stored in a database file created by pyrosar.drivers.Archive. With db_file either a full path to an existing database can be provided or it will be created in work_dir if only a filename is provided. E.g., db_file = scenes.db will automatically create the database file /<work_dir>/scenes.db.

  • dem_type

Options: Copernicus 10m EEA DEM | Copernicus 30m Global DEM II | Copernicus 30m Global DEM | GETASSE30

The Digital Elevation Model (DEM) that should be used for processing.

Note that water body masks are not available for “Copernicus 30m Global DEM” and “GETASSE30”, and will therefore not be included in the product data mask. “Copernicus 10m EEA DEM” and “Copernicus 30m Global DEM II” (both include water body masks) are retrieved from the Copernicus Space Component Data Access system (CSCDA), which requires registration. The processor asks for authentification during runtime if one of these options is selected.

  • gdal_threads

Temporarily changes GDAL_NUM_THREADS during processing. Will be reset after processing has finished.

Sections

Configuration files in INI format can have different sections. Each section begins at a section name and ends at the next section name. The config.ini file used with the ERS_NRB package should at least have a dedicated section for processing related parameters. This section is by default named [PROCESSING] (see example config file).

Users might create several sections in the same configuration file with parameter values that correspond to different processing scenarios (e.g., for different areas of interest). Note that each section must contain all necessary configuration parameters even if only a few are varied between the sections.

Command Line Interface

Once a configuration file has been created and all of its parameters have been properly defined, it can be used to start the processor using the command line interface (CLI) tool provided with the ERS_NRB package.

The following options are currently available:

ERS_NRB --help

Print a help message for the CLI tool.

ERS_NRB -c /path/to/config.ini

Start the processor using parameters defined in the default section of a config.ini file.

ERS_NRB -c /path/to/config.ini -s SECTION_NAME

Start the processor using parameters defined in section SECTION_NAME of a config.ini file.