A Parallel Architecture and Implementation for Near-Lossless Hyperspectral Image Compression Based on CCSDS 123.0-B-2 With Scalable Data-Rate Performance

Hyperspectral and multispectral imaging maintains a crucial role in remote sensing technology for Earth observation missions. However, the huge volume of produced data requires compression for storage and downlink transmission. In 2019, the Consultative Committee for Space Data Systems (CCSDS) released the CCSDS 123.0-B-2 recommended standard, allowing near-lossless compression, through a closed-loop quantizer, by introducing a Hybrid Entropy Coder option. However, the in-loop quantizer introduced additional data dependencies constituting a throughput performance bottleneck. This contribution addresses the need for high data-rate on-board compression by presenting an efficient parallel architecture and hardware implementation based on CCSDS 123.0-B-2. It bypasses the throughput performance bottleneck with an external, hardware-efficient quantizer while maintaining competitive quality near-lossless functionality with compatibility to the CCSDS standard. The parallel architecture leverages segmentation along the X-axis of the spectral cube, enabling scalable data-rate performance with constant embedded memory footprint. The introduced architecture is implemented in VHSIC hardware description language (VHDL) indicatively targeting Xilinx Kintex UltraScale technology, validated and demonstrated using state-of-the-art SpaceFibre serial link interface IP Cores and test equipment, achieving very high code coverage. A single hyperspectral compression engine (HCE) achieves throughput performance of 285 MSamples/s (4.56 Gb/s) at 1.68 W, while six parallel HCEs reach 1590 MSamples/s (25.44 Gb/s) at 6.12 W, measured on a full breadboard system. Maximum performance only depends on image dimensions, available field programmable gate array (FPGA) resources and high-speed serial interface technology. To the best of our knowledge, this implementation achieves the highest data-rate performance for near-lossless compression based on CCSDS 123.0-B-2 implemented in FPGA technology suitable for next-generation institutional missions.