Simulation Of ISAR Imaging For A Misile Target And Research On Interference Techniques On ISAR

Inverse synthetic aperture radar (ISAR) is a high resolution radar which obtains its high range resolution by using large bandwidth signal and high cross range resolution using Doppler information generated by relative movement between radar and the target. It can generate images for moving targets such as aircrafts, missiles, ships and heavenly bodies, which makes it an effective measure for millitary target identification, especially for airborne moving targets and an important role in future air and missile defense systems. Therefore, it is of parctical significance to carry on researches on ISAR jamming techniques. In this paper, ISAR images of ballistic missiles using physical optics are simulated in the first palce, based on which, techniques of active barrage jamming and passive spoofing jamming are researched.Firstly, theories about ISAR imaging are presented. After imaging principles are introduced, range and cross range resolutions of two dimensional ISAR images are calculated, then, small rotational angel based range-Doppler (RD) FFT algorithms which is frequently applied in ISAR imaging is given, and imaging plane and qualities analysis problems are discussed.Secondly, ISAR images of ballistic missiles targets are simulated. missile models are established and theories of physical optics are expounded, then scattering fields of missile models, i.e. targets'radar echoes, are calculated. Based on the works above, ISAR imaging results of missile targets are generated using RD FFT algorithms mentioned above, next, different varying phenomena of two dimensional images of missiles targets and its correponding reasons under different radar incident angles are analyzed in details.According to analyzing above , ISAR jamming techniques for missile targets are elaborated afterwards.For active jammings, ISAR barrage jamming techniques are investigated. Principles of barrage jamming are discussed and three noise modes which of them are radio frequency noise, amplitude modulated nosie and phase modulated noise respectively are established. Then, barrage jamming for single scatter and multi-scatters each are simulated and jamming effects for these three noise modes are analyzed theoretically.For passive jammings, method of dihedral corner reflectors used as towing baits for missile targets are brought forward. Radar scattering fields are calculated for dihedral corner reflectors using physical optics and ray tracing theories, then, ISAR two dimensional images of the reflectors are obtained. Based on this procedure, imaging results of missile target baits using three dihedral corner reflectors and four dihedral corner reflectors are simulated seperately and compared with that of the real missile target models.