Simulation of active cylindrical and planar millimeter-wave imaging systems

The Pacific Northwest National Laboratory (PNNL) is engaged in the development of next-generation active cylindrical and planar millimeter-wave imaging systems that strive to have higher resolution and improved image fidelity relative to currently deployed systems. The principal method to evaluate the performance of potential imaging system designs has been to emulate them using single-channel radar transceivers that were raster-scanned using x-y scanners for planar scans, or an x-y scanner coupled to a turntable for cylindrical scans. This method has several drawbacks, including the necessity of having an available millimeter-wave transceiver and limiting scanning configurations to quasi-monostatic, uniformly sampled configurations. Modern designs may incorporate sparse, multi-static, sampling strategies, and may deviate from uniform sampling schemes. High-performance computers now allow realistic simulation of many imaging configurations, eliminating the need for such laboratory scanning to evaluate potential designs. In this paper, the use of a commercially-available shooting-and-bouncing-rays simulator for these applications is described and demonstrated with a number of imaging results.