Uninhabited Aerial Vehicle
UAVSAR, a reconfigurable, polarimetric L-band synthetic aperture radar (SAR), is specifically designed to acquire airborne repeat track SAR data for differential interferometric measurements. Differential interferometry can provide key deformation measurements, and is important for studies of earthquakes, volcanoes and other dynamically changing phenomena.
Using precision real-time GPS and a sensor controlled flight management system, the system can fly predefined paths with great precision (to be within a 10 m diameter tube about the desired flight track).
The radar is designed to be operable on a UAV (Uninhabited Aerial Vehicle), but will initially be demonstrated on a NASA Gulfstream III. The radar is fully polarimetric, with a range bandwidth of 80 MHz (2 m range resolution), and a range swath greater than 16 km.
The antenna may be electronically steered along track to assure that the antenna beam can be directed independently, regardless of speed and wind direction.
Other features supported by the antenna include elevation monopulse and pulse-to-pulse re-steering capabilities that will enable some novel modes of operation. The system will nominally operate at 41,000 ft (13800 m).
The Primary Objectives of the UAVSAR Project are to:
- Develop a miniaturized polarmetric L-band synthetic aperture radar (SAR) for use on an unmanned aerial vehicle (UAV) or minimally piloted vehicle
- Develop the associated processing algorithms for repeat-pass differential interferometric measurements
- Conduct measurements of geophysical interest, particularly changes of rapidly deforming surfaces such as volcanoes or earthquakes
The Primary Science Objectives of the UAVSAR Project:
- The geophysical processes associated with natural hazards such as earthquakes and volcanoes occur over a wide range of temporal and spatial scales, and express themselves as subtle deformations in the Earth's crust.
- Present observational capabilities include sampling quickly varying surface change using in situ GPS methods, or observing fine spatial scale changes using interferometric synthetic aperture radar (InSAR).
- Generate fine resolution, accurate observations of crustal deformation resulting from natural hazards at hourly intervals.
- Driven by slow plate motions, rapid injection of magma into the plumbing system of a volcano can lead to explosive eruptions over several hours or even days. Measurements from this system will lead to better models of the internal plumbing and magma flow within a volcano.
- Steady slip along a fault in the crust can lead to sudden, major earthquakes and days of continuing slip. Using measurements from this system, a better understanding and assessment of the rate of slip and rebound surrounding a seismic event can be obtained.
- Additional science studies include rapidly moving glaciers and volumetric decorrelation studies in ice and vegetation.