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Math and StatisticsTheoretical Mathematics

Phase History Decomposition for efficient Scatterer Classification in SAR Imagery

Authors: Dane F Fuller; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
Abstract:
A new theory and algorithm for scatterer classification in SAR imagery is presented. The automated classification process is operationally efficient compared to existing image segmentation methods requiring human supervision. The algorithm reconstructs coarse resolution subimages from subdomains of the SAR phase history. It analyzes local peaks in the subimages to determine locations and geometric shapes of scatterers in the scene. Scatterer locations are indicated by the presence of a stable peak in all subimages for a given subaperture, while scatterer shapes are indicated by changes in pixel intensity. A new multi-peak model is developed from physical models of electromagnetic scattering to predict how pixel intensities behave for different scatterer shapes. The algorithm uses a least squares classifier to match observed pixel behavior to the model. Classification accuracy improves with increasing fractional bandwidth and is subject to the high-frequency and wide-aperture approximations of the multi-peak model. For superior computational efficiency, an integrated fast SAR imaging technique is developed to combine the coarse resolution subimages into a final SAR image having fine resolution. Finally, classification results are overlaid on the SAR image so that analysts can deduce the significance of the scatterer shape information within the image context.

Limitations: APPROVED FOR PUBLIC RELEASE
Description: Doctoral thesis
Pages: 194
Report Date: 15 Sep 2011
Report Number: A762255
Keywords relating to this report:
ACCURACY
ALGORITHMS
ANALYSTS
AUTOMATION
CLASSIFICATION
COMPUTATIONS
EFFICIENCY
GEOMETRIC FORMS
IMAGE PROCESSING
IMAGES
INTEGRATED SYSTEMS
INTENSITY
LEAST SQUARES METHOD
MODELS
PEAK VALUES
PHASE STUDIES
PHYSICAL PROPERTIES
POSITION(LOCATION)
RESOLUTION
SCATTERING
SEGMENTED
SHAPE
STABILITY
SYNTHETIC APERTURE RADAR
TARGET CLASSIFICATION
THEORY
THESES
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