Current Science

Open Access Open Access  Restricted Access Subscription Access

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


Affiliations
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.
User
Notifications
Font Size

  • Spudis, P. D. et al., MiniSAR: an imaging radar experiment for Chandrayaan-1 mission to the Moon. Curr. Sci., 2009, 96(4), 533– 539.

  • Spudis, P. D. et al., Initial results for the North Pole of the Moon from Mini-SAR, Chandrayaan-1 mission. Geophys. Res. Lett., 2010, 37, L06204; doi:10.1029/2009GL042259.

  • Mohan, S., Das, A. and Chakraborty, M., Investigation of polarimetric properties of lunar surface using Mini-SAR data. Curr. Sci., 2011, 101(2), 159–164.

  • Mohan, S., Saran, S. and Das, A., Scattering mechanism-based algorithm for improved mapping of water-ice deposits in the lunar polar regions. Curr. Sci., 2013, 105(11), 1579–1587.

  • Pieters, C. M. et al., Character and spatial distribution of OH/H2O on the surface of the Moon seen by M3 on Chandrayaan-1, Science, 2009, 326, 568–572.

  • Spudis, P. D. et al., Evidence for water ice on the Moon: results for anomalous polar craters from the LRO Mini‐RF imaging radar, J. Geophys. Res.: Planets, 2013, 118, 2016–2029.

  • Mishra, P., Kumar, S. and Singh, D., An approach for finding possible presence of water ice deposits on Lunar craters using MiniSAR data. IEEE J. Sel. Topics Appl. Earth Obs. Remote Sensing, 2015, 8(1), 30–38.

  • Fa, W., Wieczorek, M. A. and Heggy, E., Modeling polarimetric radar scattering from the lunar surface: study on the effect of physical properties of the regolith layer. J. Geophys. Res., 2011, 116, E03005; doi:10.1029/2010JE003649.

  • Pandey, D., Saran, S., Das, A. and Chakraborty, M., A simplistic approach to model radar backscatter from lunar regolith. In 44th Lunar and Planetary Science Conference (LPSC), Abstr. 1941, 2013.

  • Pandey, D., Das, A., Saran, S. and Chakraborty, M., Scattering characteristics of lunar regolith with respect to dual-frequency SAR: preliminary simulation results. In LPSC XLIV, Abstr. 126, 2013.

  • Putrevu, D., Das, A., Vachhani, J. G., Trivedi, S. and Misra, T., Chandrayaan-2 Dual-frequency SAR: further investigation into lunar water and regolith. Adv. Space Res., 2016, 57, 627–646.

  • Campbell, B. A., Grant, J. A. and Maxwell, T., Radar penetration in Mars analog environments. In LPSC XXXIII, Abstr. #1616, 2002.

  • Bell, W. S., Thomson, B. J., Dyar, M. D., Neish, C. D., Cahill, J. T. S. and Bussey, D. B. J., Dating small fresh lunar craters with Mini-RF radar observations of ejecta blankets. J. Geophys. Res., 2012, 117, E00h30.

  • Desai J. Ami, Mohan, S. and Murty, S. V. S., Impact ejecta characterization for small-sized fresh and degraded lunar craters using radar data. Curr. Sci., 2016, 110(10), 1929–1938.

  • Raney, R. K., Hybrid-polarity SAR architecture. IEEE Trans. Geosci. Remote Sensing, 2007, 45, 3397–3404.

  • Chan, Y. K., Chung, B. K. and Chuah, H. T., Transmitter and receiver design of an experimental airborne synthetic aperture radar sensor. Progress. Electromagn. Res., 2004, 49, 203–218.

  • Vijayan, S., Mohan, S. and Murty, S. V. S., Lunar regolith thickness estimation using dual frequency microwave brightness temperature and influence of vertical variation of FeO + TiO2. Planet. Space Sci., 2015, 105, 123–132.


Abstract Views: 421

PDF Views: 141




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

Abstract Views: 421  |  PDF Views: 141

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