Research For Solve The Target Fuzzy For High Frequency Ground Over-The-Horizon Radar

High frequency ground wave over-the-horizon radar can locate the naval ships and low-flying targets. At the same time, it is a new monitoring method for Marine resource management and development provides. Therefore, many countries have invested a lot of energy for high frequency ground wave radar research. For the ships platform, as a result of the sea, targets may be on either side. When we the transmission of electromagnetic wave by transmitting antenna in single direction detection, because of the antenna array cannot completely block in another direction, if there have targets at another side, also can produce echo signal, we mistakenly believe that the target is in which side we want to detect, creating a bilateral target fuzzy. If you don’t solve this problem, we can’t judge the targets in which side. And we cannot get the position of the target. So this paper is set in shipboard high frequency ground wave radar, study how to eliminate the bilateral target fuzzy. This article main content is as follows:First, this paper introduces the causes of bilateral target fuzzy in shipboard high frequency ground wave radar. At the ideal environment, set up the array radar signal model, and analyses the theory for how to engender the target fuzzy at two sides. We also created the model for understand the target fuzzy at two side.Second, we discuss the mutual coupling effect by the effect of array antenna orientation. By establishing the mutual coupling error model, analyzed the effect of mutual coupling on array pattern. By reconstructing array flow pattern, eliminate the effect of mutual coupling effect on array pattern. Ensure the correctness of the array pattern.Third, aiming at the amplitude error and phase error, analyzed the effect of array pattern. In application, no matter what processing method is used, the influence of the amplitude error and phase error should be faced. Therefore, this paper studies the measurement and compensation techniques of amplitude error and phase error in the receiving array antenna. Described the influence on DOA estimation. Through the method of big target, measured the amplitude error and phase error of the array units. In the end, the auxiliary element method and self-calibration method are used to compensate the array amplitude error and phase error. The correctness of the method is verified by the spatial spectrum and the array pattern.Finally, the factors that affect the directional characteristics of the antenna array are resolved, discussion on how to eliminate the ambiguity of bilateral target. By changing the direction of the array, to achieve the ideal situation of the lifting of bilateral target fuzzy. And verified the correctness of the method.