干旱区生态环境知识资源中心

The Resourcesat-2 (RS2), launched on April 20, 2011 is a follow-on mission to the successfully operational Resourcesat-1 (RS1). Similar to the RS1, RS2 carries 3 multispectral imagers in its platform: the Advanced Wide-Field Sensor (AWiFS), the Linear Imaging Self-Scanner (LISS 3) and the high-resolution multi-spectral scanner LISS-4. This study focuses on assessment of the radiometric calibration stability of RS2 AWiFS sensor by comparing near-simultaneous measurements of Terra MODIS acquired over CEOS reference standard targets. The AWiFS sensor operates four distinct spectral bands: B2 (0.52-0.59 mu m), B3 (0.63-0.69 mu m), B4 (0.77-0.86 mu m) and B5 (1.55-1.7 mu m) with a spatial resolution of 56 m. Only those bands of the Terra MODIS spectrally matching to AWiFS bands are compared after basic corrections for variations due to the sun and satellite angles with reference to scene center and the atmospheric transmittance on the given day of acquisition. Synchronous acquisitions of these sensors over the desert regions in Libya, Algeria and Egypt at CEOS recommended geographic coordinates were acquired and processed to compare the top-of-atmosphere (TOA) reflectance from both sensors. Preliminary results and future efforts are also discussed in this paper.