The Study Of FMCW ISAR Imaging Algorithms

Inverse synthetic aperture radar (ISAR) is a high-resolution microwaveimaging system, with the ISAR technology’s development, and ISAR is widelyused in civilian and military aspects, In order to appealing to both civilian andmilitary field, imaging sensors are required to be low-cost, low-powered, andcompact. Coherent pulsed radars do not account for these requirements as muchas FMCW radar. However, FMCW ISAR radars transmit a linear modulatedcontinuous wave, besides the advantage as describe in the front, they have a lowtransmitting power, low intercept probability, and high anti-interference. AnFMCW the ISAR is not only a simple structure, low-cost advantages ability,Therefore, FMCW ISAR’s development will be the concern of a growing numberof national research institutions.In this paper, the main task is to research the key problem of theoreticalstudy and practice in FMCW ISAR. Firstly, introduce the development andadvantages of the FMCW ISAR, and the meaning of this topic, and the FMCWISAR’s development prospects.Secondly, the rotating platform imaging model based on the pulsed ISAR isintroduced, based on the rotating platform model, using rang and Doppleralgorithm when the coherent integration angle is small, and the polar formatalgorithm under the coherent integration angle,then introduce the interpolationin once in the polar format algorithm.Thirdly, based on the rotating platform imaging model, introduced how toestablish the FMCW ISAR echo signals, analysis the difference of the echosignal between the pulse ISAR and the FMCW ISAR, detailed the advantage ofDechirp processing, and the effect on the range resolution.Finally, a target is supposed to moving along a rectilinear trajectory,FMCW ISAR is used to reconstruct the image. Introduces when the targetmoving can similarly see as the "stop-and-go" conditions in the FMCW mode,the quantitative analysis the effect of the Residual Video Phase and oblique.Highlighting introduced the FMCW ISAR autofocus algorithm.