Motion compensation of short-range, wide-beam synthetic aperture radar

[摘要] Up to now, SAR systems are a well known possibility for long-range detection.Applying them for short-range applications with wide-beam antennas, ofcourse, does not increase the resolution but the probability to detect hiddentargets with an anisotropic radar cross section significantly in comparisonto other detection systems. Working with an appropriate wavelength evenimproves the possiblity to look through natural cover like grass. Anapplication is detecting fawn while pasture mowing. The main issue in suchapplications is the antenna's motion in range direction as it is carried bycars or traction engines. If motion is not compensated, the phase cannot bereconstructed correctly, the resolution gets poorer and, in worst case, thetarget even disappears. Conventional methods for motion compensation eitherfail for wide beam antennas, since for contributions of wide angles the phasereconstruction is incorrect, or is not applicable for realtime dataprocessing, because the processing time due to interpolation or similar stepsis very high. We present a method of image reconstruction regarding motion ofthe antenna as well as wide beamwidth. This method is analyzed concerningprocessing time in comparison to the conventional image reconstruction. Inour system we use a combination of algorithms. There is shown a comparisonfor different algorithms dependent of the antenna's motion and apertureangle.

[学科分类] 电子、光学、磁材料