Band Descriptor Format

The DDDB band descriptor file is used to define which data of the SMOS Data Block Structures is displayed as a product band in SNAP. The band descriptor file is a line based text file (comma separated file) that is using the vertical-bar character ( |) as separator. A line beginning with a number-sign (# ) is treated as comment line. The file extension must be .csv.

The following table lists all properties that may be used to describe a band.

Name	Type	Explanation
visible	boolean	Should the band appear in the SNAP product tree (true or false).
band	string	Band name used in SNAP
dataset	string	The name of the dataset (in the original datablock structure)
pol	int	The band polarization. 0 = X, 1 = Y, 2 = XY/YX, 4 = irrelevant
sampleModel	int	Defines how 64-bit integers are handled. 0 = default (no special treatment), 1 = lower 32 bits, 2 = higher 32 bits
scalingOffset	double	Scaling offset applied to the raw data
scalingFactor	double	Scaling factor applied to the raw data
typicalMin	double	Typical (scaled) minimum value
typicalMax	double	Typical (scaled) maximum value
cyclic	boolean	Is the value range cyclic?
fillValue	double	Value indicating no-data in SNAP
validExpr	string	Valid-pixel expression used in SNAP
unit	string	Physical unit
description	string	Band description text displayed in SNAP
flagCoding	string	For flag bands only: the name of the flag coding
flags	string	For flag bands only: the name of the flag descriptor resource
ancilliaryBandName	string	Name of the associated uncertainty/error band. Optional, set to '*' if not known or not applicable
gridPointData	boolean	Is the data field member of a grid point structure (true or false).
dimensionNames	string	Blank separated list of dimension names used for NetCDF export

When the value of a property is not known or it is not important for the functionality, the asterisk character (*) can be used to indicate this.

The name of a flag descriptor resource must be a name of a flag descriptor file available in the DDDB. The name must not contain any path information or a file extension, these properties are resolved by the dddb automatically.
E.g. the resource name DBL_SM_XXXX_AUX_ECMWF__0200_flags1 will be extended to flags/AUX_/ECMWF_/DBL_SM_XXXX_AUX_ECMWF__0200_flags1.csv.

Below is an example of a band-properties file. This example is taken from the operational resources of the SMOS-Box:

    # visible | band       | dataset    | pol | sampleModel | scalingOffset | scalingFactor | typicaMin | typicalMax | cyclic | fillValue | validExpr | unit | decription                                   | flagCoding | flags | ancilliaryBandName | gridPointData | dimensionNames
         *    | SSS1       | SSS1       | *   | *           | *             | *             | 0.0       | 40.0       | *      | -999.0    | *         | psu  | Sea surface salinity using Roughness Model 1 | *          | *     | Sigma_SSS1         | true          | n_grid_points
         *    | Sigma_SSS1 | Sigma_SSS1 | *   | *           | *             | *             | 0.1       | 1.5        | *      | -999.0    | *         | psu  | Theoretical uncertainty computed for SSS1    | *          | *     | *                  | true          | n_grid_points