UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Two-Stage Change Detection for Synthetic Aperture Radar

Cha, M; Phillips, RD; Wolfe, PJ; Richmond, CD; (2015) Two-Stage Change Detection for Synthetic Aperture Radar. IEEE Transactions on Geoscience and Remote Sensing , 53 (12) pp. 6547-6560. 10.1109/TGRS.2015.2444092. Green open access

[thumbnail of Wolfe_TSCD_rv_v6_forUCL.pdf]
Preview
Text
Wolfe_TSCD_rv_v6_forUCL.pdf - Accepted Version

Download (4MB) | Preview

Abstract

Coherent change detection using paired synthetic aperture radar (SAR) images is often performed using a classical coherence estimator that is invariant to the true variances of the populations underlying each paired sample. While attractive, this estimator is biased and requires a significant number of samples to yield good performance. Increasing sample size often results in decreased image resolution. Thus, we propose the use of Berger's coherence estimate because, with the same number of pixels, the estimator effectively doubles the sample support without sacrificing resolution when the underlying population variances are equal or near equal. A potential drawback of this approach is that it is not invariant since its distribution depends on the pixel pair population variances. While Berger's estimator is inherently sensitive to the inequality of population variances, we propose a method of insulating the detector from this acuity. A two-stage change statistic is introduced to combine a noncoherent intensity change statistic given by the sample variance ratio, followed by the alternative Berger estimator, which assumes equal population variances. The first-stage detector identifies pixel pairs that have nonequal variances as changes caused by the displacement of sizeable object. The pixel pairs that are identified to have equal or near-equal variances in the first stage are used as an input to the second stage. The second-stage test uses the alternative Berger coherence estimator to detect subtle changes such as tire tracks and footprints. We show experimentally that the proposed method yields higher contrast SAR change detection images than the classical coherent change detector (state of the art), the alternative coherent change detector, and the intensity change detector. Experimental results are presented to show the effectiveness and robustness of the proposed algorithm for SAR change detection.

Type: Article
Title: Two-Stage Change Detection for Synthetic Aperture Radar
Open access status: An open access version is available from UCL Discovery
DOI: 10.1109/TGRS.2015.2444092
Publisher version: http://dx.doi.org/10.1109/TGRS.2015.2444092
Language: English
Additional information: Copyright © 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Keywords: Coherence estimation, coherent change detection (CCD), interferometric synthetic aperture radar processing, synthetic aperture radar (SAR)
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Statistical Science
URI: https://discovery.ucl.ac.uk/id/eprint/1477241
Downloads since deposit
314Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item