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Environmental act on Underwater Surveillance Systemsin ...
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Environmental Imp act on Underwater Surveillance Systems in Estuary Areas Hongyuan Shi, Dov Kruger, and Jeffrey V. Nickerson Surveillance systems normally rely on remote sensors and River [2]. The coverage area is computed from environmental detectors to collect information on suspicious movements. For data of a typical spring day. The detection probability is a port by a river or the sea, such surveillance systems should evaluated based on an average sound level from underwater cover all space dimensions: terrestrial, aerial, and underwater. targets [3]. For the same area, we further evaluate sensor Our work focuses on the design of remote sensing and coverage and detecting probability in other seasons since detecting systems for the underwater environment around water conditions change vastly at different time of the year estuary areas. (Fig. 1). We compare the results of several cases and Monitoring underwater environments has several serious summarize the impact of different environmental factors. The challenges. Even though terrestrial and aerial surveillance result shows that careful planning is required for sensor techniques are well developed, they are typically based on the placement in an estuary area. transmission of electromagnetic and optical waves. However Our future work will incorporate deception detection. We optical and electromagnetic waves have extremely high aim to design a sensor placement strategy to construct a robust attenuation in water. This inhibits directly adopting terrestrial and effective underwater surveillance system. and aerial detecting technologies to underwater usage. Most existing underwater detection technologies rely upon sound waves, as sound can travel a relatively long distance in water. Underwater detection can be performed by active and 40 passive SONARs [1]. Based on environmental concerns, 45 *> f passive sound SONARs or detectors are normally selected for K * fixed deployment. Unlike active SONARs, which emit sounds x K * to surrounding areas, passive SONARs only collect sound O 55 N x signals from surroundings. Based on signatures of the sounds x 60 generated from various sources, passive SONARs can X xx estimate the distance from a sound source. They can also 65X recognize possible movements and even type of subjects. F 70 W--V/inter XX 00 Because the information processing depends entirely upon the Spring 75 Summer quality of received sound signals, it is critical to ensure that X Autumn the transmission path from the sound source is sufficient for 30 400 500 600 700 800 the sensor to detect the signal clearly. However underwater Range (m) sound propagation is highly susceptible to water conditions. Fig. 1. Sound transmission loss in different seasons at one covered spot in the Hudson estuary area (computed from NYHOPS data using the Bellhop Sharp gradients in salinity and temperature cause sound to ray and Gaussian beam tracing program [4]). refract and reflect. Thus the listening range, or coverage, of a sound detector is largely influenced by the underwater environment. This effect is particularly prominent in estuary REFERENCES areas where fresh water mixes with sea water, and tidal action [1] R. J. Urick, Principles of underwater sound, 3rd ed., McGraw-Hill, causes significant water current changes. 1983. causes significant water current changes. [2] The New York Harbor Observing and Prediction System (NYHOPS) We study the behavior of estuary water conditions and [Online]. Available: http://hudson.dl.stevens-tech.edu/NYHOPS/ attempt to understand the environmental impacts on the [3] R. Stolkin, A. Sutin, S. Radhakrishnan, M. Bruno, B. Fullerton, A. Ekimov, and M. Raftery, "Feature based passive acoustic detection of a performance of underwater sensing and detecting systems. In diver," presented at the SPIE Defense and Security Symp., 2006. this poster, we concentrate on sensor coverage variations. [4] Underwater Acoustic Propagation Modeling Software V1.6 [Online]. Environmental data is extracted from the NYHOPS ocean Available: w.cmst.curtineduau/products/actoolbox/ model with periodic calibration from fixed CTD (Conductivity, Temperature and Depth) stations in the Hudson H. Shi and J. V. Nickerson are with the Center for Decision Technologies, Howe School of Technology Management, Stevens Institute of Technology, Hoboken, NJ 07030 USA (e-mail: {hshi, jnickerson}@stevens.edu). D. Kruger is with the Center for Maritime Systems, Stevens Institute of Technology, Hoboken, NJ 07030 USA (e-mail: [email protected]). 1-4244-1330-3/07/$25.00O 02007 IEEE. 3B9
Transcript of Environmental act on Underwater Surveillance Systemsin ...
Environmental Impact on UnderwaterSurveillance Systems in Estuary Areas
Hongyuan Shi, Dov Kruger, and Jeffrey V. Nickerson
Surveillance systems normally rely on remote sensors and River [2]. The coverage area is computed from environmentaldetectors to collect information on suspicious movements. For data of a typical spring day. The detection probability isa port by a river or the sea, such surveillance systems should evaluated based on an average sound level from underwatercover all space dimensions: terrestrial, aerial, and underwater. targets [3]. For the same area, we further evaluate sensorOur work focuses on the design of remote sensing and coverage and detecting probability in other seasons sincedetecting systems for the underwater environment around water conditions change vastly at different time of the yearestuary areas. (Fig. 1). We compare the results of several cases and
Monitoring underwater environments has several serious summarize the impact of different environmental factors. Thechallenges. Even though terrestrial and aerial surveillance result shows that careful planning is required for sensortechniques are well developed, they are typically based on the placement in an estuary area.transmission of electromagnetic and optical waves. However Our future work will incorporate deception detection. Weoptical and electromagnetic waves have extremely high aim to design a sensor placement strategy to construct a robustattenuation in water. This inhibits directly adopting terrestrial and effective underwater surveillance system.and aerial detecting technologies to underwater usage. Mostexisting underwater detection technologies rely upon soundwaves, as sound can travel a relatively long distance in water.
Underwater detection can be performed by active and 40
passive SONARs [1]. Based on environmental concerns, 45 *> fpassive sound SONARs or detectors are normally selected for K *
fixed deployment. Unlike active SONARs, which emit sounds x K *to surrounding areas, passive SONARs only collect sound O 55 N x
signals from surroundings. Based on signatures of the sounds x 60generated from various sources, passive SONARs can X xxestimate the distance from a sound source. They can also 65Xrecognize possible movements and even type of subjects. F 70 W--V/inter XX 00Because the information processing depends entirely upon the Spring
75 Summerquality of received sound signals, it is critical to ensure that X Autumnthe transmission path from the sound source is sufficient for 30 400 500 600 700 800the sensor to detect the signal clearly. However underwater Range (m)sound propagation is highly susceptible to water conditions. Fig. 1. Sound transmission loss in different seasons at one covered spot in
the Hudson estuary area (computed from NYHOPS data using the BellhopSharp gradients in salinity and temperature cause sound to ray and Gaussian beam tracing program [4]).refract and reflect. Thus the listening range, or coverage, of asound detector is largely influenced by the underwaterenvironment. This effect is particularly prominent in estuary REFERENCESareas where fresh water mixes with sea water, and tidal action [1] R. J. Urick, Principles ofunderwater sound, 3rd ed., McGraw-Hill,causes significant water current changes. 1983.causes significant water current changes. [2] The New York Harbor Observing and Prediction System (NYHOPS)We study the behavior of estuary water conditions and [Online]. Available: http://hudson.dl.stevens-tech.edu/NYHOPS/
attempt to understand the environmental impacts on the [3] R. Stolkin, A. Sutin, S. Radhakrishnan, M. Bruno, B. Fullerton, A.Ekimov, and M. Raftery, "Feature based passive acoustic detection of aperformance of underwater sensing and detecting systems. In diver," presented at the SPIE Defense and Security Symp., 2006.
this poster, we concentrate on sensor coverage variations. [4] Underwater Acoustic Propagation Modeling Software V1.6 [Online].Environmental data is extracted from the NYHOPS ocean Available: w.cmst.curtineduau/products/actoolbox/model with periodic calibration from fixed CTD(Conductivity, Temperature and Depth) stations in the Hudson
H. Shi and J. V. Nickerson are with the Center for Decision Technologies,Howe School of Technology Management, Stevens Institute of Technology,Hoboken, NJ 07030 USA (e-mail: {hshi, jnickerson}@stevens.edu).
D. Kruger is with the Center for Maritime Systems, Stevens Institute ofTechnology, Hoboken, NJ 07030 USA (e-mail: [email protected]).
1-4244-1330-3/07/$25.00O 02007 IEEE. 3B9
