Flags:¶

-e

Print extended metadata information

--help

Print usage summary

--verbose

Verbose module output

--quiet

Quiet module output

--ui

Force launching GUI dialog

Parameters:¶

pattern=string

Semantic label search pattern (examples: L, S2, .*_2, S2_1)

operation=string

Operation to be performed
Options: print
Default: print

Image collections¶

Image collections are the common data type to reference time series of multi band data. It is used in many frameworks (see Google Earth Engine API for example) to address multi spectral satellite images series. GRASS supports a multi-band raster layer approach basically with the imagery group concept (i.group). A new semantic label concept is designed in order to support image collections in GRASS GIS.

Band reference registry files¶

Band reference information is stored in JSON files with a pre-defined internal data structure. A minimalistic example is shown below.

{


    "Sentinel2": {


        "description": "The Sentinel-2 A/B bands",


        "shortcut": "S2",


        "instruments": "MultiSpectral Instrument (MSI) optical and infrared",


        "launched": "23 June 2015 (A); 07 March 2017 (B)",


        "source": "https://sentinel.esa.int/web/sentinel/missions/sentinel-2",


        "bands": {


            "1": {


                "Sentinel 2A" : {


                    "central wavelength (nm)": 443.9,


                    "bandwidth (nm)": 27


                },


                "Sentinel 2B" : {


                    "central wavelength (nm)": 442.3,


                    "bandwidth (nm)": 45


                },


                "spatial resolution (meters)": 60,


                "tag": "Visible (Coastal/Aerosol)"


            },


            "2": {


                "Sentinel 2A" : {


                    "central wavelength (nm)": 496.6,


                    "bandwidth (nm)": 98


                },


                "Sentinel 2B" : {


                    "central wavelength (nm)": 492.1,


                    "bandwidth (nm)": 98


                },


                "spatial resolution (meters)": 10,


                "tag": "Visible (Blue)"


            }


        }


    }
}

Each series starts with an unique identifier ("Sentinel2" in example above). Required attributes are only two: a shortcut and bands. Note that a shortcut must be unique in all band reference registry files. Number of other attributes is not defined or even limited (in example above only description and instruments attributes are defined). List of bands is defined by a bands attribute. Each band is defined by an identifier ("1", "2" in example above). List of attributes describing each band is not pre-defined or limited. In example above each band is described by a central wavelength (nm), bandwidth (nm), and a tag.

Band reference identifier defined by pattern option is given by a shortcut in order to print band reference information for whole series or by specific shortcut_band identifier.

System-defined registry files are located in GRASS GIS installation directory ($GISBASE/etc/i.band.library). Note that currently i.band.library allows managing only system-defined registry files. Support for user-defined registry files is planned to be implemented, see KNOWN ISSUES section for details.

Print all available band references¶

i.band.library
S2_1 Visible (Coastal/Aerosol)
S2_2 Visible (Blue)
...
L7_1 Visible (Blue)
L7_2 Visible (Green)
...
L8_1 Visible (Coastal/Aerosol)
L8_2 Visible (Blue)
...

The module prints band reference and related tag if defined.

Filter band references by a shortcut¶

Only band identifiers related to Sentinel-2 satellite will be printed.

i.band.library pattern=S2
S2_1 Visible (Coastal/Aerosol)
...
S2_12 SWIR 2

Filter band references by a regular expression¶

Print all available 2nd bands:

i.band.library pattern=.*_2
S2_2 Visible (Blue)
L7_2 Visible (Green)
L8_2 Visible (Blue)
...

Print extended metadata for specified band identifier¶

Extended metadata related to the first band of Sentinel-2 satellite will be printed.

i.band.library -e pattern=S2_1
description: The Sentinel-2 A/B bands
shortcut: S2
instruments: MultiSpectral Instrument (MSI) optical and infrared
launched: 23 June 2015 (A); 07 March 2017 (B)
source: https://sentinel.esa.int/web/sentinel/missions/sentinel-2


    band: 1


        Sentinel 2A:


                central wavelength (nm): 443.9


                bandwidth (nm): 27


        Sentinel 2B:


                central wavelength (nm): 442.3


                bandwidth (nm): 45


        spatial resolution (meters): 60


        tag: Visible (Coastal/Aerosol)