SeaDog

Figure ll ICx Technologies SeaDog underwater explosives detection sensor mounted on an autonomous underwater vehicle. Figure courtesy of ICxTechnologies. 

In another study, Darrach et al. [2] reported that samples collected near intact UUXO targets contained traces of explosives at up to parts per billion (ppb) concentration levels. The samples were analyzed in the laboratory, using solid-phase microextraction (SPME) to extract target analytes from the samples. The samples were then processed using a reversal electron attachment detection (READ) technique. If the levels of contamination found in these studies are representative of that emanating from most UUXO, the implication is that sensitive chemical sensors such as the SeaDog may be useful for detecting UUXO. 

The SeaDog sensor utilized in this work is capable of near real-time detection of low concentrations of explosives in water. The sensor utilizes novel sensing materials originally developed by collaborators at MIT. These materials are fluorescent polymers that are highly emissive when deployed as solid-state thin films. When the polymers interact with nitroaromatic explosives such as TNT, the fluorescence is quenched [3-5], The response of these materials to target analytes... 

Figure 6.1 Schematic of the first SeaDog sensor design.

Figure 6.2 SeaDog sensor and pump housings mounted for robotic integration.

Figure 6.3 SeaDog mounted on the Foster-Miller crawler during testing.

Diver-Deployed SeaDog and Initial Integration with the REMUS... 

Figure 6.4 SeaDog deployed on the REMUS during a sea trial.

Figure 6.5 SeaDog sensor payload configured for deployment on the REMUS.

Figure 6.6 SeaDog sensor package configured for diver deployment.

Figure 6.11 Diver-deployed SeaDog sensor during sea trials.

In June 2003, the SeaPup sensor was tested at a site off the Atlantic coast. As was discussed in Section 6.4.3, the SeaPup sensor showed almost an order of magnitude improvement in sensitivity over the SeaDog due to design enhancements incorporated into the system. In addition, the SeaPup responds much more rapidly to TNT than the SeaDog, which is an important advantage for mapping chemical plumes in the marine environment. 

In 2001, the Fido system was modified to operate underwater and became known as the SeaDog. The U.S. Navy Office of Naval Research (ONR), under its Chemical Sensing in the Marine Environment (CSME) Program, funded the integration of the SeaDog with an autonomous underwater vehicle (AUV). The integrated system was able to map a plume of trinitrotoluene (TNT) in open water in real time. This was the first demonstration of the mapping of an explosive plume underwater in real time [9, 10],... 

The SeaDog is also available in two configurations. A handheld version can be easily used by divers, while the AUV model is specifically configured for integration with underwater autonomous vehicles, such as the REMUS (Remote Environmental Monitoring Unit) shown in Figure 9.8. 

Chapter 6, Detection of Trace Explosive Signatures in the Marine Environment. Since the main subject is underwater experience with the SeaDog sensor,... 

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