TITLE:      Rate allocation for SAR video phase history data compression
AUTHORS:    J. Owens, M. W. Marcellin, and B. R. Hunt
CONFERENCE: Asilomar Conference on Signals, Systems, and Computers,
            Pacific Grove, California, November 1997.
ABSTRACT:
Complex phase history data in synthetic aperture radar (SAR) systems 
require extensive processing before useful images can be obtained.  
Spotlight mode SAR systems are able to obtain useful images very 
efficiently by weighting and transforming the 2-D phase history data using 
a series of 1-D operations.  Aperture weighting and inverse Fourier transforms 
are applied to the 2-D phase history data on a row by row basis followed by 
the same processing on a column by column basis.

In this paper, we are concerned with the compression of the complex phase 
history data obtained by a spotlight SAR system.  We exploit knowledge of 
the aperture weighting function along with Fourier transform processing to 
attach a ``gain'' factor to each complex phase history data sample.  This 
gain factor is then used to efficiently allocate bits to the phase history 
data during quantization.  Performance evaluations are presented for this 
compression system relative to other existing SAR phase history data 
compression systems.