Research On MIMO Distributed ISAR Imagingalgorithm

As the traditional Inverse Synthetic Aperture Radar (ISAR) imaging technologymore and more matures, its restrictive conditions in some complicated cases is beingproposed step by step. In recent years, in order to solve the limitation of the traditionalISAR imaging problems, native and foreign researchers are focusing on many otheraspects of ISAR imaging research.Due to many complicated factors in actual application of ISAR imaging whichusing traditional R-D imaging algorithm, the coherent accumulation of the availableimaging time is short which could not meet the requirements of the resolution with theresult that it affects the imaging effect, in turn, affects target recognition. Furthermore,the image of traditional ISAR imaging is the associated radar vertical plane projectionof target which is the compression of a spatial three-dimensional target in twodimensional plane so it could not meet the requirement of three dimensional ISARimaging to target recognition. In this paper, to overcome the limitations of traditionalR-D imaging algorithm in certain extent, a series of study on ISAR imagingtechnology are done and lots of associated results are achieved.The basic principles of traditional R-D ISAR imaging algorithm are firstlydiscussed, in which the model of ISAR imaging of smooth moving targets, radaremission and echo signal processing method, R-D distance-azimuth resolution anddifferent motion compensation for ISAR imaging are introduced in detail. Theeffectiveness and correctness of the traditional theory of R-D algorithm are verifiedby the results of simulation and measured data processing. According to the differentlimitations of traditional R-D algorithm, the following two aspects were studied inthis paper.Distributed ISAR imaging algorithm is a kind of ISAR imaging technologywhich is proposed in recent years. It can overcome the restriction of coherentaccumulation of the available imaging time in complicated cases. With using manymultiple-input and multiple-output radars which transmit a group of RF signals tosame targets, range profiles of every receiving channel are achieved. Using selection,interpolation, combination of received range profiles from different radars, theazimuth imaging is finished finally. The effects of distributed MIMO-ISAR imagingto smooth moving target in several cases are studied in this paper, the theory andresults of simulation show that the coherent integration time of this method is shorterthan traditional R-D algorithm with the same required azimuth resolution and theazimuth resolution is higher than R-D algorithm with the same required coherentintegration time which means the applicability and the quality of ISAR imaging is improved with the algorithm.Interferometric ISAR algorithm can achieve the three-dimensional informationof target by using the interference between several radar ISAR images which is acombination of ISAR imaging and interferometry. In this article, the principle ofinterferometric ISAR is discussed, some problems of the process of imaging is solved.The simulation results show that this algorithm can achieve three-dimensional imageof target which can meet the needs of the target three-dimensional information in thetarget recognition basically.