Kritzinger, P.J. A Spaceborne Synthetic Aperture Radar (SAR) Processor Design. MSc Dissertation. Department of Electrical Engineering, University of Cape Town, 1991.
This thesis describes the software design of a general purpose digital processor for the decoding of spaceborne SAR data. The first section develops a unified theoretical basis to explain the mechanism of operation of SAR. The second section is concerned with the design of a spaceborne SAR processor. Range correlation, range walk correction, azimuth correlation and the effects of range migration are considered.
Synthetic Aperture Radar (SAR) has many possible applications for the Southern African Region and therefore, because no expertise was available in SA for decoding of SAR data, it was decided that a facility for SAR research should be created. This research facility was realised at the University of Cape Town.
This thesis is the first phase of a project launched by the research facility, which comprises of the software design of a general purpose digital processor for the decoding of spaceborne SAR data. The thesis is divided into two main sections. The first is concerned with the development of a unified theoretical basis to explain the mechanism of operation of SAR. The second section is concerned with the design of a spaceborne SAR processor.
In Chapter 2, it is proved that SAR can be treated in its entirety from a signal processing perspective. Most of the specialised theory and techniques used to discus SAR processing are relatively standard processing techniques as used in the signal processing literature. Azimuth SAR processing is shown to be no more complicated than the digital correlation of a sampled signal, where this signal is simply the Doppler waveform associated with a moving target.
In Chapter 3, an algorithm design is proposed for a digital processor to decode spaceborne SAR data. This design is general enough to accommodate data from a variety of spaceborne SAR systems, each with its own orbital geometry and system parameters. Simulated data is used to test the validity and sensitivity of these algorithms.
To illustrate the operation of decode algorithms in terms of numerical values, real system and orbital values are used throughout Chapter 3. These values were obtained from the “Shuttle Imaging Radar B Experiment” (SIR-B).
The proposed software design was implemented at UCT and tested on raw radar data of Cradock in South Africa. This data was obtained from the SIR-B experiment. A fully processed SAR image of the region, obtained using the algorithm design outlined in this thesis, is included in Chapter 3.