Wavelength-Resolution SAR Incoherent Change Detection Based on Image Stack

Abstract

Abstract-The paper presents a wavelength-resolution SAR incoherent change detection method based on image stack, i.e. there are more than one reference or/and surveillance image. Considering image stack in statistical hypothesis test for change detection is expected to result into a simple mathematical expression for implementation and provide better change detection results. As presented in this paper, a statistical hypothesis test is developed on bivariate Gaussian distribution for an image stack of two reference and one surveillance images. The requirement for the image stack is three images associated with three measurements with no change between two of them. A detection method with simple processing scheme is proposed. The method is experimented with 24 CARABAS data sets. The results indicate that high average detection probability, e.g. 96%, with very low false alarm rate, e.g. only 0.19 per square kilometer, is obtained with the proposal.

Wavelength-Resolution SAR Ground Scene Prediction Based on Image Stack

“…Because large scatterers are associated with low-frequency components, they tend to be less influenced by environmental effects and are stable in time. Hence, by using multi-passes with identical heading and incidence angle of the illuminating platform at a given ground area, an image package with similar statistics can be obtained [17]. In [18], clutter statistical models for stacks of very-high-frequency (VHF) wavelength-resolution SAR images are discussed.…”

“…Change detection algorithms (CDA) have been widely considered over the years in the detection of distinct targets in SAR images [22][23][24]. In particular, the wavelength-resolution SAR change detection is an important topic of research and has been studied for more than a decade [17]. Wavelength-resolution systems have also shown unique results with high detectability rate on a low false alarm rate per square km, as presented, for example, in [17,24].…”

“…In particular, the wavelength-resolution SAR change detection is an important topic of research and has been studied for more than a decade [17]. Wavelength-resolution systems have also shown unique results with high detectability rate on a low false alarm rate per square km, as presented, for example, in [17,24]. The nature of the wavelength-resolution SAR imagery can be exploited to facilitate the design of CDAs, since (i) the contribution of small scatterers to radar echoes is not significant for the wavelength of several meters; (ii) scatter from large objects are the main contribution; (iii) large scatterers are usually stable in time and less sensitive to environmental effects; and (iv) the wavelength-resolution almost totally cancel the speckle noise [16] in the SAR image given a very stable backscattering between measurements.…”

“…Generally, in wavelength-resolution systems, a CDA can be simply obtained by the subtraction of two single-look images (reference and surveillance), followed by a thresholding operation. However, an image stack can be considered instead of just two images in a CDA; such a collection of images leads to improved detection performance, as discussed in [17]. This information is used to eliminate clutter and noise in the surveillance image [17], and consequently, enhancing CDA results.…”

“…However, an image stack can be considered instead of just two images in a CDA; such a collection of images leads to improved detection performance, as discussed in [17]. This information is used to eliminate clutter and noise in the surveillance image [17], and consequently, enhancing CDA results. Recently, a study using a small stack of multi-pass wavelength-resolution SAR images for change detection was introduced in [17].…”