Abstract:
The brightness temperature (Tb) is considered a
fundamental climate data record that governs the radiance
traveling towards the satellite from the top of the atmosphere. It
is used to derive the wind speed, cloud liquid water and sea
surface temperature. The optical sensors play a vital role in the
retrieval of Tb but also affected by the clouds and different solar
illuminations. On the other hand, scatterometer offers the
day/night data delivery even in cloudy conditions and insensitive
towards solar illuminations. Scatterometer Satellite
(SCATSAT-1) based on Ku-band (13.5 GHz), is launched by
ISRO (Indian Space Research Organization) on 26th September
2016. Besides backscattering coefficients (sigma-naught and
gamma-naught), SCATSAT-1 also provides the Tb for slices and
footprints that are derived from scatterometer noise
measurement, expressed in units of the temperature (deg. K).
The SCATSAT-1 Level 4 Tb product is available at two
different polarization modes i.e. HH and VV. The main
objective of this study is to retrieve the Tb at HH and VV over a
part of Western Himalayas (Himachal Pradesh, India) using the
SCATSAT-1 backscattering and validating the results using
MODIS (Moderate Resolution Imaging
Spectroradiometer) data. Based on similarity measures, it is
found that SCATSAT-1 achieved the well-correlation [R
squared 0.8311 (for VV) and 0.8343 (for HH)] with MODIS Tb.
This study can be utilized in many remote sensing applications
in flood detection or other natural disasters.
