Real Time Coincidence Processing Algorithm for Geiger Mode LADAR using FPGAs

This paper introduces the first ever Geiger-mode ladar processing algorithm that is suitable for implementation on an FPGA enabling real time processing and data downlink. Current airborne Geiger-mode ladar systems obtain high resolution and wide area coverage, but require sensors and processing counterparts with large size, weight, and power (SWaP) requirements. We are developing an airborne Micro-ladar system that collects up to 1 billion samples/sec, weighs on the order of 250 grams, consumes no more than 20W and fits in a package not much larger than a coffee cup (320cc). To reduce SWaP, we developed embedded FPGA real time processing algorithms that take noisy raw data, streaming at upwards of 1GB/sec, and filters the data to obtain a nearly noise-free 3D point cloud with high compression rates, resulting in a2MB/sec output data rate that can be readily downlinked to the ground over typical UAV communication links. A physical 64x256 Geiger-mode ladar array was integrated with an FPGA processing board running a baseline processing algorithm where the processing board has 8 orders of magnitude lower SWaP (m3kgW) than typical airborne ladar processing systems. Quantitative results using simulated ladar data input indicate that the new FPGA algorithm produces data with quality comparable with previous state of the art 3D ladar processing algorithms while suffering a reduction in area coverage rates.