A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Sikhakolli, Rajesh
- Top of Atmosphere Flux from the Megha-Tropiques ScaRaB
Authors
1 Atmospheric and Oceanic Sciences Group, Earth, Ocean, Atmosphere, Planetary Sciences and Applications Area, Space Applications Centre (ISRO), Ahmedabad 380 015, IN
Source
Current Science, Vol 104, No 12 (2013), Pagination: 1656-1661Abstract
One of the important payloads on-board the joint Indo- French Megha-Tropiques satellite is the Scanner for Radiation Budget (ScaRaB). It is dedicated for monitoring the Earth Radiation Budget (ERB) parameters at Top of Atmosphere (TOA). In this article, details of the algorithm used for computing two important ERB components, namely TOA reflected shortwave and emitted longwave fluxes from ScaRaB radiance measurements are presented along with preliminary crosssatellite validation results.
The ScaRaB flux computation algorithm is similar to the one used in the ERB Experiment. The maximum likelihood estimation algorithm is used for identification of different Earth scenes and cloud types. First, the raw radiances are corrected for spectral filtering effects followed by implementation of scene-type dependent angular correction to deduce shortwave and longwave fluxes. The instantaneous TOA flux data derived from ScaRaB radiance measurements are compared with similar data available from Clouds and Earth's Radiant Energy System (CERES) onboard Aqua and Terra satellites. Preliminary comparison confined to two months period (September- October 2012) using the two satellites suggests that the ScaRaB data are in good agreement with the CERES data. The bias-corrected ischolar_main mean square difference in ScaRaB longwave flux is 4.7 and 5.3 Wm-2 with respect to CERES on-board Aqua and Terra satellites respectively. For ScaRaB shortwave flux, it is 25.9 Wm-2 and 25.5 Wm-2 with respect to CERES onboard Aqua and Terra satellites respectively. A detailed comparison of ScaRaB TOA flux data with more than one-year of CERES data is already initiated. Results from the preliminary comparison exercise suggest that the ScaRaB data can be used with confidence for ERB studies.
Keywords
Atmosphere, Computation Algorithm, Megha-Tropiques Mission, Scarab Instrument.Full Text
- SCATSAT-1 Scatterometer Data Processing
Authors
1 Space Applications Centre, ISRO, Ahmedabad 380 015, IN
2 National Remote Sensing Centre, ISRO, Hyderabad 500 625, IN
Source
Current Science, Vol 117, No 6 (2019), Pagination: 950-958Abstract
SCATSAT-1 carries a Ku-band scatterometer with a scanning pencil beam configuration. It deploys two beams, a vertically polarized outer beam and a horizontally polarized inner beam, to cover a swath of 1800 km. The mission mainly caters to oceanographic applications and weather forecasting, with the data being extensively used for cyclogenesis predictions across the globe and specifically, the tropical region. Since the launch of SCATSAT-1 in September 2016, the satellite and payload performances as well as mission and ground segment operations have been found to be nominal and satisfactory. This article highlights various levels of operational data products as well as algorithms used for deriving radar backscatter and retrieving wind vector data from scatterometer measurements.Keywords
Data Products, Footprint, Scatterometer, Slices, Wind Vector.Full Text
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