Determination of image resolution from SAS image statistics

James L. Prater, Jonathan L. King, Daniel C. Brown

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations

Abstract

The quality of a SAS image is affected by the coherence across the synthetic aperture which is directly related to errors in motion estimation, compensation, or physical phenomena (e.g. medium instability or acoustic multipath). Operational use of a SAS system can benefit from metrics that estimate image quality and identify areas where sonar imagery is suboptimal. Furthermore, an estimate of the coherence across the synthetic aperture would be necessary to maintain a system calibrated response and use acoustic measurements to determine target or seafloor physical properties. This paper proposes techniques to determine the mean point object response and relates this parameter to image resolution. Unlike previous attempts to determine image resolution that relied on the use of specifically designed targets intended to provide an ideal point response, this technique relies on a statistical approach where the image is assumed to contain many point-like objects. The point objects are identified by comparison with seafloor statistics, and the 3dB peak width is measured for all identified point objects in the image. Analysis of the point object results provides the mean image resolution in two dimensions as well as local variability of resolution across the image. The resolution response provided by this technique was verified by reprocessing samples of SAS imagery while varying the aperture length and bandwidth and determining the resolution of the sample images. Comparison of the predicted and measured resolution response is shown.

Original languageEnglish (US)
Title of host publicationOCEANS 2015 - MTS/IEEE Washington
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9780933957435
DOIs
StatePublished - Feb 8 2016
EventMTS/IEEE Washington, OCEANS 2015 - Washington, United States
Duration: Oct 19 2015Oct 22 2015

Publication series

NameOCEANS 2015 - MTS/IEEE Washington

Other

OtherMTS/IEEE Washington, OCEANS 2015
CountryUnited States
CityWashington
Period10/19/1510/22/15

All Science Journal Classification (ASJC) codes

  • Signal Processing
  • Oceanography
  • Ocean Engineering
  • Instrumentation
  • Acoustics and Ultrasonics

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