Multiple discrete autofocus
US5248976A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 27, 1991 |
| Grant date | Sep 28, 1993 |
| Priority date | — |
| Expiry date | Nov 27, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/9019
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and autofocus processor that is adapted to automatically correct focus phase errors associated with synthetic array radar signals. The method comprises processing the synthetic array radar signals to produce a SAR image; identifying and locating potential targets contained in the SAR image; storing the range bin and azimuth location of the target in a target list; bandpass filtering the SAR signals associated with the target scatterer to remove the interference therefrom; forming the pulse pair product of the phase history samples from each reference target to produce a differential phase function; integrating the differential phase function over all reference targets to provide the averaged differential phase history associated therewith; interpolating the averaged differential phase function to restore the original time scale and number of samples; and computing the focus error from interpolated differential phase history. The focus error is estimated as a weighted average of the phase history of the detected scatterers. The autofocus processor automatically finds targets and combines data from multiple scatterers effectively and efficiently. The autofocus processor exte…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.