Bistatic SAR Processing
Contact Persons
Arnold. Barmettler |
Keywords
synthetic aperture radar, bistatic SAR, SAR image processing
Quick Reference
In contrast to monostatic SAR, bistatic SAR offers the possibility of separating radar transmitter and receiver and thus increases flexibility of the SAR system. However, by allowing a higher degree of freedom, the SAR processing algorithms developed for the monostatic case have to be extended for allowing bistatic SAR geometry.
To study bistatic SAR geometry, RSL is developing a software package to simulate the different bistatic SAR configurations. In the simulated data the trajectories of the transmitter and reciever as well as the trajectory of a moving target can be choosen arbitarily. Futhermore, for the bistatic real world case a flight campaign was held in autumn 2007 with the Swedish VHF SAR CARABAS-II (see also Ultra Wideband SAR) for a test region in Niesen, Switzerland.
Some Results
The first image was produced using RSL's bistatic SAR processor from a raw data file generated by the RSL bistatic SAR simulator. The flight track of the transmitter was a straight line, while the receiver and the target had a fixed position. The figure shows the reconstructed SAR image for this point target in normal and log scale.
The second image shows the bistatic SAR image of the test region in Spiez, Switzerland. Similar to the simulated case the flight track of the transmitter was close to a straight line while the receiver was located at a fixed position.
Bistatic SAR image of Spiez, Switzerland (4kmx4km). RSL-processed based on range compressed data courtesy FOI.
Method
For the bistatic SAR processing, we developed an extended version of the backprojection algorithm. The advantage of this algorithm is its capability of processing arbitrary track configurations of the transmitter and receiver and its high processing quality. The drawback is the relatively high computation time.
Partnerships
Research has been conducted in cooperation with the following organizations: