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L- and S-band Polarimetric Synthetic Aperture Radar on Chandrayaan-2 Mission


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1 Space Applications Centre, Ahmedabad 380 015, India
 

Dual-frequency Synthetic Aperture Radar (SAR) operating in L- and S-band frequencies is one of the primary payloads of the Chandrayaan-2 orbiter. This payload with the capability of imaging in dual frequency (L-band: 24 cm wavelength and S-band: 12 cm wavelength) with full polarimetric mode aims for unambiguous detection, characterization and quantitative estimation of water-ice in permanently shadowed regions over the lunar poles. The payload will address the ambiguities in interpreting high values of circular polarization ratio associated with water-ice observed during previous missions to the Moon through imaging in dual-frequency fully polarimetric SAR mode. Various improved system features such as wide range of resolutions and incidence angles, synchronized Land S-band operations, radiometer mode, are built into the instrument to meet the required science objectives, adhering to stringent mission requirements of low mass, power and data rates. Major scientific objectives of dual-frequency polarimetric SAR payload are: unambiguous detection and quantitative estimation of lunar polar water-ice; estimation of lunar regolith dielectric constant and surface roughness; mapping of lunar geological/morphological features and polar crater floors at high-resolution, and regional- scale mapping of regolith thickness and distribution.

Keywords

Circular Polarization Ratio, Dual Frequency, Lunar Polar Water-ice, Synthetic Aperture Radar.
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  • L- and S-band Polarimetric Synthetic Aperture Radar on Chandrayaan-2 Mission

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Authors

Deepak Putrevu
Space Applications Centre, Ahmedabad 380 015, India
Sanjay Trivedi
Space Applications Centre, Ahmedabad 380 015, India
Anup Das
Space Applications Centre, Ahmedabad 380 015, India
Dharmendra Pandey
Space Applications Centre, Ahmedabad 380 015, India
Priyanka Mehrotra
Space Applications Centre, Ahmedabad 380 015, India
S. K. Garg
Space Applications Centre, Ahmedabad 380 015, India
Venkata Reddy
Space Applications Centre, Ahmedabad 380 015, India
Shalini Gangele
Space Applications Centre, Ahmedabad 380 015, India
Himanshu Patel
Space Applications Centre, Ahmedabad 380 015, India
Devendra Sharma
Space Applications Centre, Ahmedabad 380 015, India
R. Sijwali
Space Applications Centre, Ahmedabad 380 015, India
Nikhil Pandya
Space Applications Centre, Ahmedabad 380 015, India
Amit Shukla
Space Applications Centre, Ahmedabad 380 015, India
Gaurav Seth
Space Applications Centre, Ahmedabad 380 015, India
V. M. Ramanujam
Space Applications Centre, Ahmedabad 380 015, India
Raj Kumar
Space Applications Centre, Ahmedabad 380 015, India

Abstract


Dual-frequency Synthetic Aperture Radar (SAR) operating in L- and S-band frequencies is one of the primary payloads of the Chandrayaan-2 orbiter. This payload with the capability of imaging in dual frequency (L-band: 24 cm wavelength and S-band: 12 cm wavelength) with full polarimetric mode aims for unambiguous detection, characterization and quantitative estimation of water-ice in permanently shadowed regions over the lunar poles. The payload will address the ambiguities in interpreting high values of circular polarization ratio associated with water-ice observed during previous missions to the Moon through imaging in dual-frequency fully polarimetric SAR mode. Various improved system features such as wide range of resolutions and incidence angles, synchronized Land S-band operations, radiometer mode, are built into the instrument to meet the required science objectives, adhering to stringent mission requirements of low mass, power and data rates. Major scientific objectives of dual-frequency polarimetric SAR payload are: unambiguous detection and quantitative estimation of lunar polar water-ice; estimation of lunar regolith dielectric constant and surface roughness; mapping of lunar geological/morphological features and polar crater floors at high-resolution, and regional- scale mapping of regolith thickness and distribution.

Keywords


Circular Polarization Ratio, Dual Frequency, Lunar Polar Water-ice, Synthetic Aperture Radar.

References





DOI: https://doi.org/10.18520/cs%2Fv118%2Fi2%2F226-233