Tactical Synthetic Aperture Radar The Tactical Synthetic Aperture Radar ( TSAR ) is a new radar system introduced on the MQ - 8B Fire Scout unmanned aerial vehicle . It delivers high - resolution , wide - area radar images day or night , and in all weather conditions . TSAR systems take advantage of the long - range characteristics of radar signals and the information processing capability of modern digital electronics to provide high resolution imagery . The TSAR system can see through dense foliage , or penetrate sand and soil to image targets underground . How Synthetic Aperture Radar works . SAR produces a two - dimensional ( 2 - D ) image . One dimension in the image is called range ( or cross track ) and is a measure of the “ line - of - sight ” distance from the radar to the target . Range measurements and resolutions are achieved in synthetic aperture radar in the same manner as most other radars , range is determined by precisely measuring the time from transmission of a pulse to receiving the echo from a target . In the simplest SAR , range resolution is determined by the transmitted pulse width ; for example , narrow pulses yield fine range resolution . The second dimension is azimuth , or along track , and is perpendicular to range . It is the ability of SAR to produce relatively fine azimuth resolution that differentiates it from other radars . To obtain fine azimuth resolution , a physically large antenna is needed to focus the transmitted and received energy into a sharp beam . The sharpness of the beam defines the azimuth resolution . Even moderate SAR resolutions require an antenna physically larger than can be practically carried by an airborne platform : antenna lengths several hundred meters long are often required . However , airborne radar collects 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 . A narrow synthetic beam width results from the relatively long synthetic aperture , which yields finer resolution than is possible from a smaller physical antenna . [ 1 ] . SARs are not simple and transmitting short pulses to provide range resolution is generally not practical . Typically , longer pulses with wide - bandwidth modulation are transmitted . This complicates the range processing but decreases the peak power requirements on the transmitter . For even moderate azimuth resolutions , a target ’ s range to each location on the synthetic aperture changes along the synthetic aperture . The energy reflected from the target must be “ mathematically focused ” to compensate for the range dependence across the aperture prior to image formation . Additionally , for fine - resolution systems , the range and azimuth processing is coupled ( dependent on each other ) , which greatly increases the computational processing . The images generated by the TSAR are 3 - D rather than 2 - D as described above . So how does the TSAR system generate a 3 - D image ? There are actually two ways to create a 3 - D image using SAR . The first is to use two antennas . With new mathematical techniques for relating the radar reflection from the terrain surface to the time delay between radar signals received at the two antenna locations , a 3 - D image is created . If only one antenna is available , the aircraft has to fly two slightly offset passes to receive the same data . As mentioned above , Tactical Synthetic Aperture Radars also offer the capability for penetrating materials which are optically opaque , and thus not visible by optical or infrared techniques . Low - frequency SARs may be used under certain conditions to penetrate foliage and even soil . This provides the capability for imaging targets normally hidden by trees , brush , and other ground cover . To obtain adequate foliage and soil penetration , SARs must operate at relatively low frequencies ( 10 ' s of MHz to 1 GHz ) . Studies have shown that SAR may provide a limited capability for imaging selected underground targets , such as utility lines , arms caches , bunkers , land mine s , etc . Depth of penetration varies with soil conditions ( moisture content , conductivity , etc . ) and target size , but individual measurements have shown the capability for detecting 55 - gallon drums and power lines at depths of several meters . In dry sand , SAR can penetrate up to ten meters .