Data from the following sensors are presented:


ERS -1,2 SAR
TU-134, AN-24 Aircraft RAR
SIR-C/X SAR
Ocean-7 RAR

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I. ERS-1, ERS-2 SAR

European Remote Sensing Satellite (ERS-1) was launched on 17 July 1991, and the follow mission ERS-2 (with the same sensors and an Ozone monitoring instrument added) was launched on 21 April 1995.

ERS-1 and ERS-2 satellites are in similar orbits.

The ERS-1 mission is split in several phases with different repeat cycles, optimized for different applications.

ERS-2 has a fixed repeat cycle of 35 days, and follows ERS-1 tracks with one day's delay.

AMI-SAR (Active Microwave Imager in Synthetic Aperture Radar) operates at C- band (5.3 GHz, 5.6 cm), 15.55 MHz bandwidth, VV-polarization, pulse repetition frequency 1640-1720 Hz, transmitted pulse length 64ns (compressed), transmitted peak power 4.8 kW. The physical antenna size is 10m x 1m. The incidence angle on the horizontal Earth surface at mid swath is 23° (ranging from 19° at near range to 26° at far range). Swath width is 102.5 km (telemetered), spatial resolution is about 25x25 m.


II. Ku-Band Real Aperture Radar on board aircraft laboratories AN-24, Tu-134

RADAR SYSTEM PARAMETERS

Ku-band (l=2.25 cm) real-aperture radar operating with the peak power of 60 kW,  the 2 kHz pulse repetition frequency and a 110 ns transmitted pulse-width.

Two cylindrical antennas, one on each side of the aircraft, transmit and receive alternate pulses of horizontal and vertical polarizations at large incident angles of 72-84 to produce simultaneous  HH and VV images.

The radar swath of 12.5 km is illuminated on each side of ground track. Spatial resolution is about 25x25 meters.
 


III. SIR-C/X SAR

The Spaceborne Imaging Radar-C/X-band Synthetic Radar (SIR-C/X-SAR), carried in the cargo bay of the Space Shuttle Endeavour in April and October of 1994, simultaneously recorded SAR data at three wavelengths (L-, C-, and X-bands; 23.5, 5.8, and 3.1 cm, respectively). In addition, the full polarimetric scattering matrix was obtained by the SIR-C instrument at L- and C-band over a variety of terrain and vegetation types. The integrated system is steerable in look angle (electronically in the case of SIR-C, mechanically in the case of X-SAR) to obtain data in the angular range of 15-16 Degree. Imaging resolution varies from about 10 to 50 meters, depending on the geometry and data taking configuration.

Over the two flights, a total of 143 hours (93 terabits) of SAR data were digitally recorded on tape for subsequent processing in the U.S., Germany, and Italy. During the October 1994 flight of SIR-C/X-SAR, over one million square kilometers of repeat-pass SAR interferometry data were also obtained.

SIR-C/X-SAR is a cooperative experiment between the NASA (National Aeronautics and Space Administration), the German space agency, DARA (Deutsche Agentur fur Raumfahrtangelegenheiten), and the Italian Space Agency, ASI (Agenzia Spaziale Italiana). SIR-C was developed by NASA's JPL (Jet Propulsion Laboratory). X-SAR was developed by the Dornier and Alenia Spazio companies, with the DLR (Deutsche Forschungsanstalt fur Luft- und Raumfahrt), the major partner in science, operations, and data processing.


IV. Ocean-7 RAR

Ocean-7 was launched in October 1994. It was developed at the Institute of Radiophysics and Electronics of the Ukrainian Academy of Sciences. Spatial resolution is 1-3 km within a swath of 460 km. The incidence angle changes from 21° to 46° within the swath. The RAR operates at a wavelength of 3.16 cm with vertical polarization.







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