Real time synthetic aperture radar (SAAR) processing is described in the context of real world constraints. The requirements for a SAR Processor to recognize tactical targets are outlined with other necessary modes. Interface with the rest of the radar is generally described. Cost vs. architecture tradeoffs are discussed. The cost impact of LSI in relationship to the breakdown of cost at the Unit, module, and IC level is also developed. For the example chosen a multifunctional programmable architecture utilizing LSI which minimizes the total module count is least expensive.