i.lswt

Computes Lake Surface Water Temperatures (inland water bodies) from TOA Brightness Temperatures.

i.lswt [-i] ainput=name binput=name basename=basename satellite=string [--overwrite] [--verbose] [--quiet] [--qq] [--ui]

Example:

i.lswt ainput=name binput=name basename=basename satellite=string

grass.script.run_command("i.lswt", ainput, binput, basename, satellite, flags=None, overwrite=False, verbose=False, quiet=False, superquiet=False)

Example:

gs.run_command("i.lswt", ainput="name", binput="name", basename="basename", satellite="string")

Parameters

Command linePython (grass.script)

ainput=name [required]
    Brightness Temperature (10.5 - 11.5 micro m)
binput=name [required]
    Brightness Temperature (11.5 - 12.5 micro m)
basename=basename [required]
    Name for output basename raster map(s)
satellite=string [required]
    Satellite name
    Allowed values: NOAA07-AVHRR, NOAA09-AVHRR, NOAA11-AVHRR, NOAA12-AVHRR, NOAA14-AVHRR, NOAA15-AVHRR, NOAA16-AVHRR, NOAA17-AVHRR, NOAA18-AVHRR, NOAA19-AVHRR, METOPA-AVHRR, ERS1-ATSR1, ERS2-ATSR2, Envisat-AATSR, Terra-MODIS, Aqua-MODIS, GOES8-IMG, GOES9-IMG, GOES10-IMG, GOES11-IMG, GOES12-IMG, GOES13-IMG, MSG1-SEVIRI, MSG2-SEVIRI
    NOAA07-AVHRR: Use split-window coefficients for NOAA07-AVHRR
-i
    Display split-window coefficients and exit
--overwrite
    Allow output files to overwrite existing files
--help
    Print usage summary
--verbose
    Verbose module output
--quiet
    Quiet module output
--qq
    Very quiet module output
--ui
    Force launching GUI dialog

ainput : str, required
    Brightness Temperature (10.5 - 11.5 micro m)
    Used as: input, raster, name
binput : str, required
    Brightness Temperature (11.5 - 12.5 micro m)
    Used as: input, raster, name
basename : str, required
    Name for output basename raster map(s)
    Used as: output, raster, basename
satellite : str, required
    Satellite name
    Allowed values: NOAA07-AVHRR, NOAA09-AVHRR, NOAA11-AVHRR, NOAA12-AVHRR, NOAA14-AVHRR, NOAA15-AVHRR, NOAA16-AVHRR, NOAA17-AVHRR, NOAA18-AVHRR, NOAA19-AVHRR, METOPA-AVHRR, ERS1-ATSR1, ERS2-ATSR2, Envisat-AATSR, Terra-MODIS, Aqua-MODIS, GOES8-IMG, GOES9-IMG, GOES10-IMG, GOES11-IMG, GOES12-IMG, GOES13-IMG, MSG1-SEVIRI, MSG2-SEVIRI
    NOAA07-AVHRR: Use split-window coefficients for NOAA07-AVHRR
flags : str, optional
    Allowed values: i
    i
        Display split-window coefficients and exit
overwrite: bool, optional
    Allow output files to overwrite existing files
    Default: False
verbose: bool, optional
    Verbose module output
    Default: False
quiet: bool, optional
    Quiet module output
    Default: False
superquiet: bool, optional
    Very quiet module output
    Default: False

DESCRIPTION

i.lswt computes Lake Water Surface Temperature (LSWT) from moderate resolution polar orbiting satellites with dual thermal channels. Given the Top Of Atmosphere(TOA) Brightness Temperatures (BT) derived from the thermal channels of the supported satellites, the module computes surface temperature. For water surface (lakes/inland water bodies), the module uses a simplified non-linear split-window algorithm.

NOTES

The non-linear split window equation used here is:

LSWT = Ti + c1 * (Ti - Tj) + c2 * (Ti - Tj) ^ 2 + c0

Where Ti and Tj are Brightness temperatures derived from dual thermal channels 10.5 - 11.5 micro m and 11.5 - 12.5 micro m respectively. The split window equation and the coefficients c0,c1,c2 are taken from Jimenez-Munoz et.al (2008).

EXAMPLE

r.mask vect=watermask cats=1 --o
i.lswt in1=NSS.LHRR.NP.D14177.S1312_b4 in2=NSS.LHRR.NP.D14177.S1312_b5 \
  basename=NSS.LHRR.NP.D14177.S1312 satellite=NOAA19-AVHRR

REFERENCES

The satellite specific split-window coefficients are taken from:

Jimenez-Munoz, J.-C., Sobrino, J.A., 2008. Split-Window Coefficients for Land Surface Temperature Retrieval From Low-Resolution Thermal Infrared Sensors. IEEE Geoscience and Remote Sensing Letters 5, 806-809. (DOI)

A new method to develop continuos time series of LSWT from historical AVHRR is explained below, uses the same split window technique implemented here:

Pareeth, S., Delucchi, L., Metz, M., Rocchini, D., Devasthale, A., Raspaud, M., Adrian, R., Salmaso, N., Neteler, M., 2016. New Automated Method to Develop Geometrically Corrected Time Series of Brightness Temperatures from Historical AVHRR LAC Data. Remote Sensing 8, 169. (DOI)

AUTHOR

Sajid Pareeth; Fondazione Edmund Mach, Italy

SOURCE CODE

Available at: i.lswt source code (history)
Latest change: Thursday Mar 20 21:36:57 2025 in commit 7286ecf