Although work on the NASA/GSFC Search and Rescue Synthetic Aperture Radar (SAR2). project discussed below is "on hold" for the foreseeable future; SAR2 enabled development of a very promising search tool, especially for finding downed aircraft. The U.S. Navy is putting SAR2 to productive use, and NASA may eventually have the opportunity to further developed it.
The GSFC Search and Rescue Mission Office has been developing a system for locating aircraft that have crashed under conditions that severely handicap normal visual search methods, including in remote areas where a missing aircraft is hidden by vegetation, weather or darkness. NASA has shown that synthetic aperture radar may be the best candidate to meet these search requirements.
The SAR2 concept consists of a side-looking radar carried onboard a search platform, such as a business jet flying at an altitude of 25,000 to 30,000 feet, a satellite, or an unmanned aerial vehicle (UAV). For SAR2 experimentation, a NASA DC-8 jet with an experimental synthetic aperture radar system (AIRSAR) was used to image the ground as the crew flew a series of predetermined flight paths over the search area. The processed radar images can reveal man-made objects in the imaged area, enabling selection of potential crash sites for closer investigation by search aircraft and/or ground teams.
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SAR2 can penetrate foliage and clouds and conduct wide-area searches of remote areas day or night, or during periods of inclement weather. It is anticipated that SAR2 will be used when emergency beacons (ELTs) fail to operate or when other unusual circumstances prevail.
The GSFC has shown that salvaged aircraft parts (wings, tails, fuselage, etc.) can be detected under trees and through clouds, using target discrimination and polarimetric-based automatic crash site detection techniques operating on the processed radar images. Two experiments were conducted in cooperation with the National Association for Search and Rescue (NASAR), the San Bernardino County Sheriff’s Department, U.S. Forest Service staff at the San Bernardino National Forest, Jet Propulsion laboratory and NASA Dryden Flight Research Center.
Resulting included: (1) software improvements producing higher quality images, and (2) advanced motion compensation and geo-rectification techniques allowing highly accurate projection of processed radar images onto USGS maps.
Pending available funding, future objectives could include: (1) upgrading crash site detection software;
(2) coordinating long term low frequency radar approval for search and rescue;
(3) identifying teaming opportunities with operational Search and Rescue authorities;
(4) developing a prototype system to allow a proof of concept evaluation by NASAR and other search personnel; and
(5) helping in any operational follow-on efforts.
Synthetic Aperture Radar Search and Rescue (SAR2) topics presented at the 1997 S.P.I.E. Conference in Orlando, Florida.
Synthetic Aperture Radar Search and Rescue (SAR2) topics presented at the 1998 S.P.I.E. Conference in Orlando, Florida.
Synthetic Aperture Radar Search and Rescue (SAR2) topics presented at the 1999 S.P.I.E. Conference in Orlando, Florida.
Synthetic Aperture Radar Search and Rescue (SAR2) topics presented at the 2000 S.P.I.E. Conference in Orlando, Florida.