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

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

Different SAR Devices

Made in Israel 3 to 1 meter resolution

under STRIP operation. Sub-meter resolution with SPOT operation

Operates from tens of km to 100km above ground

EL/M-2055 SAR/MTI

Different SAR Devices

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

QuaSAR

Different SAR Devices

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

Lynx

Different SAR Devices

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.

MiniSar

BYU’s microSAR Weighs less than 4.4 lbs with everything included Meant to fly on UAV with 6 ft wingspan Uses PC104 stack Power consumption is nominally 18 W