USCG Improvement of Search & Rescue Capabilities

USCG Improvement of Search & Rescue Capabilities

This page has been directly copied from the USCG R&D Center Web Site. We encourage you to read it from their site to get the latest version, plus they have some nice graphics and photos. Because they use a "frames" site some of you may have difficulty in viewing or finding it plus it is a very important site, so we reproduced it below 18 Aug 1997. Additionally, their site offers the opportunity to communicate feedback and questions to them.

Research and Development Center

Improvement of Search and Rescue Capabilities



The location of search datum is poorly predicted because of uncertainties in the search object's last known position, search object leeway drift, and ocean currents. Many search platforms, sensors and search scenarios have no verified search performance information. Search planning tools/models and search performance prediction methods require validation, updating and refinement. Improved environmental files are required for the Computer Assisted Search Planning (CASP) system. Greater emphasis needs to be placed on rescue techniques. Post SAR mission analysis has not been performed nor documented adequately.


Improve the location and detection of search and rescue (SAR) targets through improved techniques of drift prediction, visual search, electronic search and search planning. Improve the ability to estimate the probability of search success. Develop improved SAR techniques and equipment. Improve the feedback of post mission analysis into SAR preparation and planning.


This project is an outgrowth of a project (Probability of Detection in Search and Rescue) initiated by a tentative operational requirement from the Coast Guard Office of Operations. That project was focused upon identifying the capabilities of Coast Guard search units in the area of visual and electronic search. This work was largely completed by 1989 for then existing Coast guard platforms and sensors. A need has been recognized to broaden the scope of the work involving SAR to include other aspects of the SAR problem. The Improvement of Search and Rescue Capabilities (ISARC) project was initiated in 1989 and established as a full project in FY90. Broad outlines of the project were set forth which organized the project into the areas of ISARC Project Management, SAR Incident Awareness, SAR Operations Planning, Evaluation of SAR Platforms and Sensors, SAR Mission Execution, and Post SAR Mission Analysis and Documentation. Under the direction of the Program Manager (G-OPR) most of the research effort has been focused on the problems of search area definition, search target movement, and search target detection.


Evaluation of search effectiveness uses a mathematically derived Probability of Detection (POD), the probability that the search object will be detected under a given set of search conditions by a given search unit or sensor. Sweep width theory assumes: (1) the target is uniformly distributed within the search area, and (2) the search unit is conducting a parallel track search and is accurately navigating along uniformly spaced tracks. The overall Probability of Success (POS) for any search must consider the errors associated with these two assumptions and the probability that the target exists within the designated search area. The ISARC project is beginning to consider the probability of survival as a possible addition to the POS equation.

Target drift has always been and remains today a major problem in search planning. Recent technological developments such as GPS, electromagnetic current meters, and satellite communications have provided the means that will now allow us to study target movement with the detail needed to accurately measure short-term responses to both wind and current. Development work is completed on a prototype of an air deployable Self-Locating Datum Marker Buoy (SLDMB) which makes use of a Global Positioning System (GPS) and satellite communications (SATCOM). A priority design concern is that the buoys faithfully follow the near surface currents. The data processing and analysis aspects of the SLDMB have been addressed in proof-of-concept studies with International Ice Patrol (IIP) and the CCG. Techniques using satellite imagery have been developed to determine surface flow regimes making use of the movement of advective thermal features in the images. Objective analysis modeling and data blending techniques have been developed for the optimization and integration of sea surface current values from a variety of sources.

Computer aids to search planning such as the CASP system have great potential for improving the accuracy and speed of the search planning function. Efforts to identify and integrate the state-of-the-art environmental data bases are being pursued. Models within the CASP system are being tested, verified, and validated.

Recently Completed and Ongoing Research

1012.3.3 CASP Performance Improvement Methodology

Conduct a review of CASP program mechanics, mathematics and resource allocation methods, and compare them to computer tools available in the Coast Guard and elsewhere. Evaluate CASP program mechanics and resource allocation techniques for effectiveness and efficiency. Develop improved modules which will maximize effective interaction with environmental data fusion methods and search theory updates developed in the 1012.3.8 (Ocean Current Data Blending) and 1012.6.5 (Review Search Theory) project elements. Review and improve the compatibility of the CANSARP system and the CASP system.

1012.3.4 Datum Marker Buoy (DMB) Development

Develop a state-of-the-art air deployable Self-Locating DMB (SLDMB) for use by CG search units which makes use of satellite navigation and communications. Develop data handling and analysis techniques for the SLDMB. Continue testing of buoy drift characteristics. Complete air-drop certification testing in support of OPS testing scheduled under 1012.3.8.

1012.3.7 Survival Suit Leeway

Complete the study of the effect of wind (leeway) on survival suits or immersion suits. Revise and publish a report on survival suit leeway research conducted by Florida Atlantic University and the Office of Naval Research.

1012.3.8 Ocean Current Data Blending

Develop techniques for the fusion or blending of ocean current data from multiple sources. Techniques and models have been identified for conducting this blending and a preliminary test was conducted in June 1996. Test region(s) will be identified in the Georges Bank region that contain diverse oceanic regimes. Three surface-truthed field tests will be conducted during calender year 1997 to validate and refine these techniques. During these tests, SLDMBs will be deployed to simulate search object motion and provide ocean surface current data to the data blending software. Identify government agency sources for providing improved ocean surface currents based upon tested data fusion and blending techniques.

1012.3.9 RADARSAT Satellite All-Weather Ocean Currents

Examine the availability and quality of images acquired from satellites using a synthetic aperture radar sensor. Data from other satellite based active microwave sensors will also be evaluated. A synthetic aperture radar is currently flying on the ERS-1 and the RADARSAT which was launched in November 1995. Identify and address problems of acquiring and processing radar images. Develop techniques for deriving surface currents, surface winds, sea state, and other features of CG interest from the images in concert with OPS testing being conducted under 1012.3.8. Cooperation with the Canadian Coast Guard is anticipated.

1012.3.10 Medium and Large Craft Leeway Theory

Develop a taxonomy for all leeway target classifications. Set the priorities of the leeway targets to be studied. Develop leeway tables for medium and large search objects under moderate to severe environmental conditions. Develop and validate a generalized model for leeway. Use the collected field data to verify the leeway model.

1012.3.11 Leeway of Small Craft

Determine leeway factors for small SAR craft on the open ocean during periods of severe weather when winds are in excess of 20 knots. The severe weather, open ocean leeway has been conducted jointly and in cooperation with the Canadian Coast Guard. New technologies of positioning, current measurement, and wind measurement will make more accurate and reliable leeway measurements possible.

1012.4.9 HH-65 Visual Detection Validation

Determine the Night Vision Goggle (NVG) detection performance of the HH-65 aircraft relative to the HH-3 and HH-60J. Formulate NVG search planning guidance and sweep widths for this platform for a representative range of targets and environmental conditions. Evaluate a prototype, full-scale onboard laser illumination device that may enhance NVG detection performance. Continue evaluating the impact of search unit illumination and alternative night vision technologies on night SAR mission detection performance.

1012.6.5 Review of Search Planning Theory

Conduct an evaluation of current search theory based on case studies. Conduct an exhaustive review of search theory literature and current research. Develop a set of recommendations for the validation, improvement, and expansion of the current Coast Guard search theory that will account for recent developments in theory and sensors. Provide for better mathematical representation of electronic and multi-sensor searches within the Coast Guard's search planning methodology.

August 08, 1997 update

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