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Title: Shadow Probability of Detection and False Alarm for Median-Filtered SAR Imagery

Technical Report ·
DOI:https://doi.org/10.2172/1323596· OSTI ID:1323596
 [1];  [2];  [3];  [3];  [3]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). ISR Analysis and Applications Dept.
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). ISR Mission Engineering Dept.
  3. General Atomics Aeronautical Systems, Inc., San Diego, CA (United States). Mission Systems

Median filtering reduces speckle in synthetic aperture radar (SAR) imagery while preserving edges, at the expense of coarsening the resolution, by replacing the center pixel of a sliding window by the median value. For shadow detection, this approach helps distinguish shadows from clutter more easily, while preserving shadow shape delineations. However, the nonlinear operation alters the shadow and clutter distributions and statistics, which must be taken into consideration when computing probability of detection and false alarm metrics. Depending on system parameters, median filtering can improve probability of detection and false alarm by orders of magnitude. Herein, we examine shadow probability of detection and false alarm in a homogeneous, ideal clutter background after median filter post-processing. Some comments on multi-look processing effects with and without median filtering are also made.

Research Organization:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); General Atomics Aeronautical Systems, Inc., San Diego, CA (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA); General Atomics Aeronautical Systems, Inc. (GA-ASI) (United States)
DOE Contract Number:
AC04-94AL85000
OSTI ID:
1323596
Report Number(s):
SAND2014-4877; 521035
Country of Publication:
United States
Language:
English