Research On Method Of Enumeration Of Targets In High Frequency Radar Based On Distributed Array

Over the past several years,high-frequency(HF)radar has been widely used in various fields such as target detectio n,guidance,and coastal environment monitoring.HF radar systems usually operate in the frequency range of 2-30 MHz.In the field of coastal observation,the observation distance can reach 200 nautical miles from the coastline.The complex electromagnetic environment interference requires high-precision high-frequency radar target number estimation at a lower snapshot and array cost.Suppressing the mutual coupling effect between antennas is an effective method to improve the estimation of the number of radar targets.Therefore,this paper studies the method of improving the estimation ability of target number in the background of high frequency radar.First of all,the general form of derivation of the estimation method of the target number of the Sparse Iterative Covariance-based Estimation(SPICE)under the limited snapshot is studied.For high-frequency radars,a higher target number estimation capability is essential.This paper analyzes the influence of the target number estimation algorithm under the covariance matrix reconstruction on the estimation accuracy of the high frequency radar target number under low snapshot.The results show that the impact on the estimation accuracy is positive under limited snapshots,and is better than the effect of the traditional MDL algorithm.Although considerable number of may be negligible,the simulation results show that the target number estimation method under covariance matrix reconstruction is an analysis method that can improve the accuracy of high-frequency radar target number estimation under certain conditions.Then,the method of estimating the number of targets for high-frequency radar under mutual coupling is studied.Based on the assumption that the internal elements of the large array antenna and the i ntermediate elements of the sub-array have the same array environment.The mutual coupling coefficient matrix is self-calibrated,and the optimized mutual coupling coefficient matrix improves the accuracy and the number and accuracy of high-frequency radar detection targets.In this paper,we conjoint mutual coupling coefficient matrix reconstruction as well as covariance matrix reconstruction to study give an expression of the model to face mutual interference of array elements from the synthesized high-frequency radar data,and compare it with the classic MDL algorithm.The results show that in low snapshots,the algorithm of sparse iterative covariance reconstruction may greatly build up the recognition rate of target number estimation in high-frequency radar.Finally,the design of the array with higher degree of freedom is studied,and the estimation experiment of the number of targets of the high-frequency radar of the array is simulated.For higher target number estimation ability,more regular antenna arrays are required.By using the sparsity of the antenna array,performance can be improved without increasing the cost of the antenna.This paper simulates the designed long-baseline distributed nested array,and estimates the number of radar targets.The number estimation method under the reconstruction of the covariance matrix is used to verify the target number estimation ability in different situations.