i.lswt - GRASS GIS manual

NAME

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

KEYWORDS

imagery, LSWT, MODIS, AVHRR, AATSR, SEVIRI, IMG

SYNOPSIS

i.lswt

i.lswt --help

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

Flags:

-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
--ui: Force launching GUI dialog

Parameters:

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; Options: 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

DESCRIPTION
NOTES
EXAMPLE
REFERENCES
SEE ALSO
AUTHOR

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)