View
2
Download
1
Category
Preview:
Citation preview
ELECTRONIC WARFARE SOUTH AFRICA 2017International Conference & Exhibition6-8 November 2017 | CSIR, Pretoria
ELECTRONIC WARFARE SOUTH AFRICA 2017International Conference & Exhibition6-8 November 2017 | CSIR, Pretoria
The Compression of Raw
SAR Data
Chané Pieterse – University of Pretoria & CSIR
Richard Focke – CSIR
Warren du Plessis – University of Pretoria
The Compression of Raw SAR Data
• Using Block Adaptive Quantisation (BAQ)
Context
• Why compress?
• Size/Weight/Power limitations of platform
• Higher resolution capabilities -> Higher data volume
• Limited onboard storage capacity
• Limited downlink capacity for real-time transmission
• Applications
• Research can be applied to phased arrays
• Data volume reduction
1
Background
• Challenges of compressing raw SAR data:• High entropy value
• High dynamic range
• No statistical redundancy to exploit
• Noise-like Gaussian characteristics of I & Q components
• Non-stationary (samples are uncorrelated)
• Presence of speckle
• Previous work• Theoretically implemented algorithms: BAQ, BFPQ, VQ, Wavelets, Compressive
Sensing, Quantization in Transform Domain
• BAQ used for Magellan mission to Venus
• BFPQ used in the Spaceborne Imaging Radar (SIR-C) mission
• ECBAQ used for ENVISAT
• FDBAQ used in Sentinel 1
2
Implementation
• Data Sets
• ERS-2 set (Spaceborne, C-band, mid-urban data)
• DST SAR sets (Airborne, C-band, pulsed & FMCW, low-urban & mid-urban data)
• Simulated SAR data
• BAQ algorithm
I BlockI component
Determine statistics of
block
Q BlockQ component
Lloyd-Max Quantizer
Raw Complex
Data
Encoded I component
Encoded Q component
3
Results – ERS-2 Data Set
4
Uncompressed – 5 bits Compressed – 4 bits
Results – ERS-2 Data Set
5
Uncompressed – 5 bits Compressed – 1 bit
Results – DST SAR Data Set (Farm)
6
Compressed - 4 bitsUncompressed – 12 bits
Results – DST SAR Data Set (Farm)
7
Compressed - 1 bitUncompressed – 12 bits
Results – DST SAR Data Set (Pecan Wood)
8
Compressed - 4 bitsUncompressed – 12 bits
Results – DST SAR Data Set (Pecan Wood)
9
Compressed - 1 bitUncompressed – 12 bits
Recommended