Implementation Of Direction Finding Algorithm Of Correlation Interferometer Based On Array Synthesis

Nowadays,with the rapid development of the radio technology,the illegal usage of the radio is more and more common.Therefore,the research of radio direction finding is particularly important.The common DF-direction finding systems include scalar method and vector method.Scalar method is simple,but it is easy to produce large deviation under large bandwidth.The vector method can detect more than two signalssimultaneously,but the direction finding system is complex and has high cost.The phase method represented by the correlation interferometer direction finding system has higher sensitivity and antiinterference ability,and the system cost is lower than that of vector method.Therefore,it has been widely applied in engineering.In order to realize accurate and real-time direction finding in engineering,the direction finding algorithm of correlation interferometer is studied and improved in this paper.In view of the difficulty of searching the maximum correlation degree and the low accuracy of the direction finding method,an improved direction finding model is proposed in this paper.By adding different roll off handling process based on the traditional model,The width of main lobe is decreased by 50%,and the peak ratio of main lobe to side lobe is increased by 40% and the difficulty of maximum correlation search is reduced with the maximum value of the correlation value unchanged.At the same time,in order to reduce the influence of the incompleteness of the sample library on the accuracy of the direction finding,the quadrant and the three spline method are adopted to optimize and interpolate the sample library,so that the sample library contains 720 standard orientation information.In order to shorten the direction finding time,this paper puts forward the local search algorithm,through rough search on the sample database,delete half related samples,by relative calculating the second samples which is consist by the remaining samples with the wave,the algorithm time consumption has decreased by 50%,the side direction time consumption has decreased by 25%.This algorithm in this paper is applied to the three channel correlation interferometer direction finding system.In order to improve the baseline length under the condition of constant antenna aperture,the array synthesis technique is introduced in this topic.The baseline is extended ?~2? in the intermediate band by the uncertainty of the relative position of the synthesized omnidirectional antenna with other elements.Finally,the improved correlation interferometer direction finding algorithm is transplanted into DSP,and the azimuth and azimuth of the given beacon are measured repeatedly by the existing test platform.The test results show that the system error is within 3° and the sensitivity is within 20 ?V/m,and the direction finding time is less than 3ms when the array synthesis technique and the improved direction finding algorithm are used.The performance is better than the traditional algorithm,which meets the requirements of this topic,and has high engineering application value.