Marino A, Dierking W & Wesche C (2016) Contrast enhancement for an iceberg detector with a CFAR test using dual-polarized radar imagery. In: 2016 European Radar Conference (EuRAD). 13th European Radar Conference (EuRAD), London, 05.10.2016-07.10.2016. London: IEEE, pp. 73-76. https://ieeexplore.ieee.org/abstract/document/7811650
The identification of small icebergs in SAR images is challenging especially when these are embedded in sea ice. In this work, a new detector is proposed based on dual-polarized incoherent SAR images. Small icebergs have a stronger cross polarization accompanied by a higher cross- over co-polarization ratio compared to sea ice in many cases. This is the rational at the base of the detector.
The new detector is tested with dual-polarization ground detected Sentinel-1a Extra Wide swath images acquired over the time span of two months. The test area is on the East Coast of Greenland, where large numbers of icebergs occur.
This work is mostly focused on the development of an
appropriate Constant False Alarm Rate for the contrast enhanced
image, that is based on a modification of the Cell-Averaging
CFAR. A quantitative comparison of the proposed detector with
an ordinary CA-CFAR using only the cross polarization channel
is provided. We focus on grounded icebergs as test targets.
The proposed methodology seems able to improve the contrast between icebergs and sea ice clutter up to 75 times. This returns
an increased probability of detection and reduced probability of
Detectors; Sea ice; Training; Synthetic aperture radar; Clutter; Scattering; Random access memory