Accurate attitude estimation using ERS-1 SAR raw data

This paper presents results from work done on the EUCLID program (European Cooperation for the Long-term In Defence). The purpose of the work is to demonstrate accurate yaw and pitch estimation using ERS-1 SAR raw data. An iterative Doppler centroid estimation technique is applied to achieve nearly the accuracy predicted from theory. Doppler centroid estimates at near and far range are used to estimate yaw and pitch and their standard deviation. The yaw and pitch were estimated with standard deviations less than 0.005 degrees and 0.002 degrees respectively. The yaw and pitch angles were typically less than about 0.03 degrees and a significant variation over one ERS-1 scene is observed. Accurate attitudes estimated from SAR data may be useful for other instruments on the same platform as the SAR, such as processing of optical images.