<title>Coastal mine detection using the COBRA multispectral sensor</title>

Abstract

The Coastal Systems Station (CSS) at Panama City, FL is developing an airborne multispectral sensor system which flies on an unmanned aerial vehicle for detecting mines in a coastal environment. This system is called the Coastal Battlefield Reconnaissance and Analysis (COBRA) system and has successfully completed preliminary developmental testing (DT-0). For this program, the Environmental Research Institute of Michigan (ERIM) developed a fieldable ground station including integrated aircraft tracking, real-time sensor data analysis, and a post processor testbed for developing and evaluating mine and minefield detection algorithms. A fully adaptive multispectral Constant False Alarm Rate (CFAR) mine detection algorithm was implemented in the post-processor by ERIM, along with patterned and scatterable minefield detection algorithms developed by SS. The algorithms do not require prior knowledge of mine spectral signatures and thus are ideal for detecting a wide variety of mines with unknown or changing spectral signatures. COBRA DT-0 testing has been performed on actual minefields deployed at coastal and inland test sites. Preliminary results show that the COBRA system, coupled with these algorithms, meets the required minefield detection performance goals. This paper reviews the algorithm theory and implementation, overviews the ground station design, and presents minefield detection results from actual minefield imagery collected over realistic scenes during DT-0 testing.

Area-based results for mine detection

“…There have been several studies of mine detection using statistical methods and involving different sensors, including [1]- [7], [12], [14]- [19]. In the case of the direct point-by-point exhaustive detection and search for mines, which is directly related to the present work, current detection techniques do not provide sufficiently high performance results, especially in cases where the minefield is heavily cluttered [9], [10].…”

Compression for small targets in multispectral imagery

“…As the threshold is successively reduced by half, the Significance Pass and Refinement Pass compute the next bit in the binary expansions of the transform values. See [3,7] for a more complete description of bitplane encoding. To realize the maximum benefits of WDR (fast implementation and low power requirement), a 4-levels Daub 5/3 Intto-Int transform is used.…”

“…A system using this type of camera has been used for airborne mine detection [7]. Currently, due to the limited datalink capacity, minefield images are recorded on board and then detected offline.…”

COBRA ATD minefield detection model initial performance analysis

“…The COBRA RX mine detection algorithm result (referred to as RX value), computed at each image pixel, is a multiband spectrallspatial anomaly detection metric [3,4,5,6,7]. It is a measure of the multi-band signal-to-clutter-ratio (SCR) of objects with a contrasting spectral response from the background.…”