Double Stand Isar Imaging Algorithm Research

High-resolution imaging sensors,such as the inverse synthetic aperture radar(ISAR),have the ability to locate,identify and track a target in a very effectiveway.Range resolution of ISAR imaging can be obtained through broadband emissionsignal,while the cross-range resolution is based on the radar relative to the rotation ofthe target formed by the Doppler shift.Compared to the traditional ISAR,bistatic ISARhave the advantages of longer distances,security,anti-jamming and anti-intercept.Bistatic ISAR has very important significance in military and civilian.In this dissertation,we introduce the theory of monostatic ISAR imaging,analysisISAR imaging turntable model,complete the echo simulation.Discussion and study thebistatic ISAR imaging method,while the synchronous phase error formula is derivedand analyzed the impact of the synchronization phase error of the bistatic ISARimaging,and simulation.1、Introduce stepped-frequency signals and establish a simple model of theturntable echo simulation with a stepped-frequency signals while have be simulated.Formotion compensation of ISAR imaging,several commonly used range migration andphase compensation method,and complete the simulation imaging.2、Compare with the range-Doppler imaging,confocal imaging effect significantlyimproved through the joint time-frequency analysis.Through analysising time-frequencydistributions,we compare the time-frequency resolution and cross-interrerence oftime-frequency imaging methods.And analysis the images of the time-frequencyimaging methods.3、Study the phase synchronization error model of bistatic ISAR echo model,analysis the impact of the imaging by the phase synchronization error.Bistatic ISAR radar imaging target practice are non-cooperative target,and themovement of the targer relative to the radar is unknown.Target parameter is diffibult toestimate and determine the impact,the scatterers drift out their range cells or theirDoppler frequency shifts are time-varying,the image reconstructed by using the Fouriertransform becomes blurred. In this dissertation we introduced the imaging algorithm based on time-frequency transform which can break the limitations of the Fourierimaging algorithm,bistatic ISAR imaging in practice some reference value.