Data compression for operational SAR missions using entropy-constrained block adaptive quantisation

Bistatic radar observations of the Moon using Mini-RF on LRO and the Arecibo Observatory

“…The second was to separate the backscattered signal of the target location from signals that come directly to the Mini-RF antenna via the Arecibo Observatory and that come from specular, forward-scattering off of the lunar surface. The signal was sampled at a fixed rate of 2.083 MHz and the resulting complexvalued data were stored as 3-bit values for later transmission to Earth using a block adaptive quantization algorithm [Kwok and Johnson, 1989;Algra 2002]. These data included the backscattered returns from the target location, specular returns from the lunar surface, and signals that reached the Mini-RF antenna directly from the Arecibo Observatory.…”

Analysis-by-synthesis compression of range-focused SAR raw data

“…The computations in (8) and (9) require a total of M cw (L + 2) − 1 additions and M cw (L + 2) multiplications for M cw samples. These operations must be performed for each vector v ∈ C in order to carry out the minimization in (7). As a result, the total number of operations for M cw samples is N cb [M cw (L + 2) − 1] additions, N cb [M cw (L + 2)] multiplications, and N cb − 1 (real) comparisons.…”

“…Among these, block adaptive quantization (BAQ) [1], which NASA used in the Magellan mission to Venus, has become a de facto standard, and several variants such as vector BAQ (BAVQ) [2] and entropy constrained BAQ [7], have been introduced. Other techniques include wavelet compression [8][9][10][11], trellis-coded quantization [12][13][14], and predictive quantization [15,16].…”

“…Compression of SAR data has been the subject of many studies in recent years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Among these, block adaptive quantization (BAQ) [1], which NASA used in the Magellan mission to Venus, has become a de facto standard, and several variants such as vector BAQ (BAVQ) [2] and entropy constrained BAQ [7], have been introduced.…”

Advanced on-board SAR Data Compressor

“…ECBAQ has been described in [2] and [3]. Recently in [4] a new version of ECBAQ has been presented using a rate control loop which is optimized for frequency domain applications.…”