Frequency diversity for image enhancement
US4561019A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1983 |
| Grant date | Dec 24, 1985 |
| Priority date | — |
| Expiry date | May 16, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S15/8954
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods for improving the availability of information derived from signals received from an object irradiated with coherent pulses of any form of radiation that exhibits a wave nature are disclosed. A method for reducing speckle derives separate component noncoherent signals from the received signals, and combines these separate noncoherent signals to form improved composite noncoherent signals. Weighting and processing of component signals can be applied as a function of time, frequency, and signal amplitude to optimize speckle reduction in all or a critical part of the signal by compensating for the range and frequency dependence of attenuation and the frequency dependence of scattering phenomena. In a method for enhancing resolution, separate component coherent signals are derived from the received signals, weighted and processed, and combined to form improved composite coherent signals; then noncoherent signals are derived from the improved composite coherent signals. In both methods, signals can be processed either in the analog or digital domains or in hybrid analog/digital domains. The apparatus for performing each method also is disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.