SAR Synthetic Aperture RADAR a high resolution

SAR (Synthetic Aperture RADAR) : a high resolution 2 -D ground mapping technique

How it Works • One dimension is called range and it is determined by “line-of-sight” distance to the target. • Another dimension is azimuth and is determined by the doppler frequencies of the returned signal.

How it Works Resolution for range is determined by pulse width of signal. Resolution for azimuth is determined by signal strength. Signal strength can be increased by increasing the size of the antenna. An antenna lengths several hundred meters long are often required. However, an airborne radar could collect data while flying this distance and then process the data as if it came from a physically long antenna. The distance the aircraft flies in synthesizing the antenna is known as the synthetic aperture.

How it Works 3 D can be acquired using two antennas and taking the phase difference between the two determine the 3 D information. Calling interferometric SAR or In. SAR.

Different SAR Devices EL/M-2055 SAR/MTI n n n Made in Israel 3 to 1 meter resolution under STRIP operation. Sub-meter resolution with SPOT operation Operates from tens of km to 100 km above ground

Different SAR Devices Qua. SAR n n n Made by EADS in Europe Weighs 66 lbs. Operates in the Ka, Ku, L, S, C, X bands Resolutions of. 3, 1, and 3 meters depending on swath Can detect moving objects moving a velocities of at least 1. 1 mph

Different SAR Devices Lynx n n n Made by General Atomics - USA Weighs 114 lbs. Operates in the Ka, Ku, L, S, C, X bands Resolutions of. 1, to 3 meters Can detect moving objects moving a velocities of 6. 2 mph – 43 mph

Different SAR Devices Mini. Sar n n Made by Sandia Labs Weighs 25 lbs. Performance of Lynx system but at a much smaller size. Can operate on medium-sized UAV Future plans predict a weight of 18 lbs.

BYU’s micro. SAR n n Weighs less than 4. 4 lbs with everything included Meant to fly on UAV with 6 ft wingspan Uses PC 104 stack Power consumption is nominally 18 W