Planned Data Products and Science Processing Paradigm for the Proposed NASA-ISRO SAR Mission

Abstract:

The proposed NASA-ISRO Synthetic Aperture Radar (SAR), or NISAR, Mission will make global integrated measurements of the causes and consequences of land surface changes. NISAR would provide a means of disentangling highly spatial and temporally complex processes ranging from ecosystem disturbances, to ice sheet collapse and natural hazards including earthquakes, tsunamis, volcanoes, and landslides. The mission would capable of performing repeat-pass interferometry and collecting polarimetric data. The core of the payload would consist of an L-band SAR to meet all of the NASA science requirements. A secondary S-band SAR would be contributed by ISRO, the Indian Space Research Organisation. The instrument would comprise a large diameter deployable reflector and a dual frequency antenna feed and associated electronics to implement the fine-resolution, polarimetric, 240-km swath imaging system. Combined with an ambitious data acquisition plan that supports continuous mapping of Earth’s land and ice-covered surfaces at every opportunity over the life of the mission, the mission would generate over 1 Petabyte of raw data each year, which expands to greater data volumes for higher level products. Since many of the science requirements propose time-series analysis, which often involve combinatorial manipulation of images acquired over time, it would be impractical and inadvisable to create global time-series science products. As a result, the processing plan for the mission would be for the project to create a complete set of products through Level 2, and only selected Level 3 products over extended areas of calibration and validation. These sites would be chosen to be scientifically interesting, so that the mission products would include significant scientific results. In addition, the project will develop higher-level processing software to the community that will allow scientists to apply the mission data from Level 0 to 2 to their science problems.