MERIS Case-2-Water Processor Description

Please note: The chapter Data Processors - Introduction provides a general description for all BEAM data processors. It describes the common graphical user interface (GUI), the command-line interface and the common processing request file format.

Content

The In- and Output Parameters

Source Product Group

Name: Used to select the spectral source product. The source product shall contain spectral bands providing a source spectrum at each pixel. Use the ... button to open a data product currently not opened in VISAT.

Target Product Group

Name: Used to specify the name of the target product.

Save to: Used to specify whether the target product should be saved to the file system. The combo box presents a list of file formats, currently BEAM-DIMAP, GeoTIFF, and HDF5.

Open in VISAT: Used to specify whether the target product should be opened in VISAT. When the the target product is not saved, it is opened in VISAT automatically.

The Processing Parameters

Perform atmospheric correction:
Enables or disables the atmospheric correction. If the correction is disabled the source product must already be atmospherically corrected and contain reflectance bands ("reflec_#").

Atmospheric correction neural net (optional):
The neural net to be used for the atmospheric correction. If it is not specified the default value will be used. Only enabled if atmospheric correction is enabled too.

Perform SMILE correction:
Whether to perform a SMILE correction or not. Only enabled if atmospheric correction is enabled too.

Output TOSA reflectance:
Whether to add TOSA reflectance bands to the target product or not. Only enabled if atmospheric correction is enabled too.

Output normalization of bidirectional reflectances:
Whether to add normalised reflectance bands to the target product or not. Only enabled if atmospheric correction is enabled too.

Output path reflectance:
Whether to add path reflectance bands to the target product or not. Only enabled if atmospheric correction is enabled too.

Output transmittance:
Whether to add transmittance bands to the target product or not. Only enabled if atmospheric correction is enabled too.

Land detection expression:
An expression to detect land pixels. Only enabled if atmospheric correction is enabled too.

Land detection expression:
An expression to detect cloud/ice pixels. Only enabled if atmospheric correction is enabled too.

Water algorithm:
The algorithm used to compute the Case-2 IOPs. Must be REGIONAL.

Output water leaving reflectance:
Whether to add water leaving reflectance bands to the target product or not. These are either computed by the atmospheric correction or are provided by the source product.

Tsm conversion exponent:
Tsm conversion factor:
Factors for converting particle scattering into total suspended matter dry weight.
Ctsm (g m-3) = tsmConversionFactor * b443^tsmConversionExponent

Chl conversion exponent:
Chl conversion factor:
Factors for converting absorption of phytoplankton pigment at 443 into chlorophyll concentration.
Chlorophyll (mg m-3) = chlConversionFactor a_pig443^chlConversionExponent

Spectrum out of scope threshold:
The out of scope (= out of training range) flag will be set if the chi2 value is above the given threshold.

Invalid pixel expression:
An arithmetic expression which defines the valid pixels for the processing. Pixels which are not valid are skipped by the processor.

Inverse water neural net:
Path to the neural network file for the inverse model (reflectances, geometry --> concentrations).

Forward water neural net:
Path to the neural network file for the forward model (concentrations, geometry --> reflectances).