The Feasibility of Using ENVISAT ASAR and ALOS PALSAR to Monitor Pastures in Western Australia

• Published in: Photogrammetric engineering and remote sensing 2014-01, Vol.80 (1), p.43-57
• Main Authors: Wang, Xin, Ge, Linlin, Li, Xiaojing, Gherardi, Stephen
• Format: Article
• Language: English
• Subjects: ALOS (satellite); Animal and plant ecology; Animal, plant and microbial ecology; Applied geophysics; Biological and medical sciences; Biomass; Earth sciences; Earth, ocean, space; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General aspects. Techniques; Internal geophysics; Moisture content; Monitors; Polarization; Soil moisture; Synecology; Synthetic aperture radar; Teledetection and vegetation maps; Terrestrial ecosystems; Western Australia
• ISSN: 0099-1112; 2374-8079
• DOI: 10.14358/PERS.80.1.43

The objective of this study is to investigate the feasibility of using dual polarization ENVISAT ASAR and ALOS PALSAR data to capture temporal and spatial variations of pasture at paddock scale in Western Australia. SAR backscatter was correlated to NDVI, NDWI, and soil moisture index (M.I) to demonstrate the capability of SAR to measure biomass, plant water content, and soil moisture, respectively. The results proved that ENVI-SAT ASAR and ALOS PALSAR are able to monitor pasture, and the ability varies with sensor parameters (wavelength, polarization, and incidence angle) and field properties (soil moisture, vegetation type, biomass level). Paddock biomass and human activities can be detected; C-band is suitable for grass biomass and L-band detects water content of grass in drying stage. HV (VH) has advantage in detecting plant water content, while VV is sensitive to soil moisture. Ground measurements of pasture biomass successfully validated part of the correlation results.