Airborne demonstration of FPGA implementation of Fast Lossless hyperspectral data compression system

Abstract

Efficient on-board lossless hyperspectral data compression reduces data volume in order to meet NASA and DoD limited downlink capabilities. The technique also improves signature extraction, object recognition and feature classification capabilities by providing exact reconstructed data on constrained downlink resources. At JPL a novel, adaptive and predictive technique for lossless compression of hyperspectral data was recently developed. This technique uses an adaptive filtering method and achieves a combination of low complexity and compression effectiveness that far exceeds state-of-the-art techniques currently in use. The JPL-developed `Fast Lossless' algorithm requires no training data or other specific information about the nature of the spectral bands for a fixed instrument dynamic range. It is of low computational complexity and thus well-suited for implementation in hardware. A prototype of the compressor (and decompressor) of the algorithm is available in software, but this implementation may not meet speed and real-time requirements of some space applications. This paper describes a hardware implementation of the `Modified Fast Lossless' compression algorithm for push broom instruments on a Field Programmable Gate Array (FPGA). The FPGA implementation has been integrated into the Next Generation Data Capture System (NGDCS) avionics system for the Airborne Visible/ Infrared Imaging Spectrometer Next Generation (AVIRISng). The NGDCS includes two airborne hardware platforms which were flown on a Twin Otter aircraft: a National Instrument PXI and the Alpha Data Systems. The FPGA implementation targets the current state-of-the-art FPGAs (Xilinx Virtex V and VI families) and compresses one sample every clock cycle to provide a fast and practical real-time solution for Space applications.