Deep Water Munitions Detection System

Abstract : Underwater UXO sites are of increasing interest to the Department of Defense cleanup community. This interest has led to the development of specialized systems for digitally mapping magnetic or electromagnetic anomalies in shallow water. These systems are essentially extensions of successful land-based technologies to the underwater environment. Yet the cost of underwater surveying is significantly greater than similar land-based activities, and extrapolation of the current generation of shallow water systems to deeper water depths would result in even greater costs. While some of the cost escalation may be unavoidable, it is desirable to consider alternate technologies and approaches. One factor limiting the ability of the research community to do this is the lack of information about typical underwater sites that could be used to benchmark alternatives. This report synthesizes data and analyses from a number of underwater UXO sites that were surveyed with existing systems. The objective is to describe what we have learned to date about the underwater UXO problem; and to delineate the performance required to meet underwater UXO survey objectives. In all seven underwater magnetometer survey sites were chosen for inclusion in this study. The sites cover a wide variety of environments in fresh and salt water, and include expected UXO areas and non-UXO areas (see Section 2). Despite the diversity, all of the sites showed some similar characteristics. While there was a wide range of target densities between the sites, and in different areas within certain sites, there were significant numbers of ferrous targets detected everywhere. As is seen at land sites that have had human use or habitation, you always find something. The large majority of targets at each site were completely buried. Thus, survey systems that cannot detect buried targets will miss a significant fraction of the total.