METRATEK, Inc......................We innovate for you!
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The AIRSAR radar was developed by METRATEK to perform air-to-air radar cross section measurements and diagnostic imaging of large and small aircraft in flight. The A-3 aircraft AIRSAR was completed in 1991. It achieved 100% mission reliability on a 2-year program during which it was dedicated to diagnostic imaging of the B-2. It was called a ``National Treasure" by the Secretary of the Air Force in Congressional testimony on the B-2 program.
Air-to-Air radar imaging measurements have been performed in both turboprop and jet aircraft. Experience with this system has proven that large aircraft can indeed be imaged in flight with the same quality and calibration accuracy that can be achieved with indoor and outdoor ranges. Most recently, the system has been flown in an A-3 Sky warrior jet. It can carry a crew of five for 4 hours of flight at speeds of 250-300 knots. The system was used to provide diagnostic images of the B-2 in a two-year program. It achieved 100% mission reliability during that period.
The two aircraft are flown in formation with the trailing aircraft maneuvering to generate the synthetic aperture data. AIRSAR software developed by METRATEK allows imaging to be performed to resolutions of a few centimeters without any inertial corrections or cooperative links between the two aircraft. Unlike most SAR images, this system provides highly calibrated radar cross section measurements, using a towed target as a reference.
The system consist of a core module that resides in the cabin of the A-3 aircraft and high and low band RF units that reside in radomes that were added to the tip of the vertical stabilizer and to an extension of the aft potion of the main fuselage. The Radar is operated from two PC-based control stations. One station provides radar control, real-time processing, and data recording and the second station operates the TV and mount control systems, displays color TV images, and dynamically places visual references to aid in target tracking. The Model 100 core module uses a fast-switching synthesizer to generate a step-chirp waveform that can cover 100 MHz to 18 GHz with an individual waveform bandwidth of up to 6 GHz. In-phase and quadrature A/D converters provide 12-bit resolution and further coherent integration results in 16- or 32-bit samples. The system is able to interleave waveforms from different frequency bands to allow simultaneous data collection.
The disk dome at the rear of the aircraft carries a log-periodic dipole array that covers 100-1000 MHz. The microwave band antennas are located in the nacelle at the tip of the vertical stabilizer. These antennas cover from 60 degrees to 300 degrees relative to the nose of the A-3; antennas mounted in the nose radome can provide forward coverage when 270 degree coverage aft of the aircraft is not sufficient. Target tracking is provided by slaving the antenna mounts to a bore sight TV.
AIRSAR technology is directly applicable to SAR or ISAR imaging of ships for identification, radar cross section measurements, and imaging diagnostics.
AIRSAR systems can be delivered with the same parameters as listed in the table of parameters on the Model 200 radar page.
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