An Investigation of Synthetic Aperture Radar Autofocus,

Abstract

SAR imagery is generated by matched filtering the raw azimuth signal history, assuming uniform straight line motion of the aircraft. Unknown aircraft motions alter the matched filter required for processing. Autofocussing involves determinating from the raw data the appropriate matched filter. In this document the principles of SAR and the requirement for an autofocus system are discussed. Three autofocus methods are investigated: measurement of the power spectrum, contrast maximisation, and registration of multilook images. The power spectrum is shown to be unreliable as an autofocus aid. Results of the contract maximisation and registration methods are compared. Keywords: Great Britain; Charts.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1985
Accession Number
ADA161912

Entities

People

  • I. P. Finley
  • J. W. Wood

Organizations

  • Royal Signals and Radar Establishment

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Accuracy
  • Aircrafts
  • Algorithms
  • Antennas
  • Cross Correlation
  • Distortion
  • Filters
  • Filtration
  • Flight Paths
  • Frequency
  • Geometry
  • Language
  • Matched Filters
  • Power Spectra
  • Radar
  • Synthetic Aperture Radar
  • White Noise

Fields of Study

  • Engineering

Readers

  • Computer Vision.
  • Radar Systems Engineering.