Ground penetrating radar incorporating a real-time multi-target direction finding capability

摘要

The Ground Penetrating Radar (GPR) system introduced in this application provides data from an underground medium of the same caliber as that provided by conventional radars in air or space applications. This includes direction as well as distance to all targets, and some indication of target shape and orientation, within a conical volume of the underground having a solid angle of about 90 degrees and a depth of about 100 feet under ideal conditions. The key to this capability is depicted in FIG. 3, and is a hemispheric dome (6) which is placed against the smoothed surface (1) of the underground medium (2), and which has a relative dielectric constant (E_R) substantially equal to that of the underground medium (2). A microwave horn antenna (3) is placed against the surface (7) of this dome (6) and moved from side to side (8) causing the radar beam (9) of the horn antenna (3) to systematically scan the entire conical volume. FIG. 9 depicts the effect of this scanning wherein a radar (21) placed against the surface (1) of the underground medium (2) has its beam (22) swept through the conical volume until the entire scene has been “photographed” in a regular pattern of about 300 pixels. These pixel data are then digitized, averaged and stored for recall and further computer processing and for display in several formats of the Operators' choosing. Data acquisition, digitizing, signal averaging and storage of the entire scene requires less than 10 seconds, after which analysis may proceed.