"The NASA-ISRO Synthetic Aperture Radar (NISAR) Mission: Global Observations for Interdisciplinary Science and Applications"
The United States National Aeronautics and Space Administration (NASA) and the Indian Space Research Organisation (ISRO) are developing an Earth-orbiting science and applications mission that will exploit synthetic aperture radar to map Earth’s surface every 12 days, persistently on ascending and descending portions of the orbit, over all land and ice-covered surfaces. The mission, known as NISAR (NASA-ISRO SAR) is by its nature multidisciplinary, with requirements for studying Earth land and ice deformation, and ecosystems, in areas of common interest to the US and Indian science communities. NISAR operates at L-band (24 cm wavelength) and S-band (10 cm wavelength), has a swath of over 240 km at 3- to 10-m resolution, and can operate in a variety of polarimetric modes. The system is designed to maintain a precisely repeating orbit to achieve high-quality repeat-pass interferometric (InSAR) performance. The science team associated with solid earth, cryosphere, and ecosystems disciplines developed specific measurement requirements, both in terms of geodetic imaging using InSAR and backscatter radiometrics, that lead to a specific comprehensive mapping plan. The applications community has provided guidance on how best to optimize these measurements for applications. Because each discipline has favored regular systematic sampling over the life of the mission as opposed to mode diversity, the opportunities for interdisciplinary studies are abundant. For example: 1) the primary mapping mode over land surfaces is L-band dual-polarization, which provides an opportunity to study solid earth deformation in the context of changes of vegetation and soil moisture; 2) Understanding subsidence as a component of understanding coastal evolution requires geodetic corrections for tidal effects; 3) Forest and agricultural disturbance and land ice and sea ice dynamics measured over the life of the mission will be inputs to climate models. This talk will describe the NISAR mission plan, and other examples of interdisciplinary possibilities.