First deformation results using the NASA/JPL UAVSAR instrument

The UAVSAR instrument, employing an L-band actively electronically scanned antenna, had its genesis in NASA's ESTO Instrument Incubator Program and after 4 years of development has begun collecting science data for investigators. System design was motivated by solid Earth applications where repeat pass radar interferometry can be used to measure subtle deformation of the surface, however flexibility and extensibility to support other applications were also major design drivers. In fact a Ka-band single-pass radar interferometer for making high precision topographic maps of ice sheets was developed and tested based to a large extent on components of the UAVSAR L-band radar. By designing the radar to be housed in an external unpressurized pod, it has the potential to be readily ported to many platforms. Initial testing is being carried out with the NASA Gulfstream III aircraft, which has been modified to accommodate the radar pod and has been equipped with precision autopilot capability developed by NASA Dryden Flight Research Center. With this the aircraft can fly within a 10 m diameter tube on any specified trajectory necessary for repeat-pass radar interferometric applications. To maintain the required pointing for repeat-pass interferometric applications we have employed an actively scanned antenna steered using INU measurement data. This paper presents a brief overview of some of the initial deformations made by the UAVSAR instrument.