Sar image encoding for data compression
US4780718A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1985 |
| Grant date | Oct 25, 1988 |
| Priority date | — |
| Expiry date | Jun 17, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/9027
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A technique is disclosed for encoding SAR image data to achieve data compression. In the image encoding stage, the SAR image is transformed into a list of high reflectivity radar discretes and a small array of frequency filters. In the target list, the location data and intensity levels above the local average background clutter are tabulated for a predetermined number of the highest intensity radar discretes. The array of frequency filters is divided into three zones; the inner, middle, and higher frequency zones relative to the d.c. filter. Only the inner and middle zones of filters are retained and the outer filters are discarded, thus acheiving the desired data reduction. The inner zone filters are quantized to a higher level of precision than the middle zone of filters. The saturation levels of the filters are determined adaptively. In the decoding stage, the original SAR image is reconstructed from the radar discrete list and the small array of frequency filters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.