| With the development of modern warfare,the detection of wireless communication signals has become one of the important factors in modern warfare.Among them,signal direction finding is one of the necessary functions in electronic countermeasures,and it is very critical to accomplish tasks such as enemy monitoring,intelligence collection,and interference strikes.In this article,a multi-band and multi-system fusion direction finding system is designed.The adaptive direction finding method is used with the direction finding antenna for different frequency bands to measure the angle.The direction finding results under different conditions are optimized by data fusion algorithm,and finally completed.System implementation and test verification.First of all,a variety of mainstream direction finding algorithms are introduced,and the characteristics and performance of different direction finding algorithms are compared and analyzed;two direction finding algorithms used in this paper,namely correlation interferometer direction finding and Wattson Watt direction finding are introduced in detail,and the analysis is made.In the process of operation,steps such as phase ambiguity resolution,correlation coefficient calculation,and quadrant analysis provide sufficient theoretical support for the implementation of the algorithm.Then,the errors in the direction finding system are analyzed,mainly including system errors and measurement errors.For the system errors introduced by the hardware technology such as channel amplitude and phase inconsistency and antenna coupling,the real-time correction method is used to correct the errors with the standard signal source as the system correction source.For non-uniform linear array,uniform circular array and orthogonal ring array direction-finding antennas,the direction-finding method above is used to complete the simulation process of fuzzy direction-finding,and the error analysis of the simulation results is carried out.Next,in view of multi-band and multi-system situations,a statistical analysis based homomorphic fusion algorithm is proposed for the calculation results within a single frequency band and single system.The data is segmented to remove noise points,and the mean is calculated as the output;A multi-system fusion algorithm based on OPTICS(Ordering Points to Identify the Clustering Structure)clustering was used to identify clustered data clusters and calculate the weighted average of the data clusters for the operation results of different systems and antennas in adjacent frequency bands.The processing results were used as the final output,and simulation analysis was conducted on the above situation.Through the comparison of the optimization results,the method optimizes the system performance,enhances the data stability,and improves the direction finding accuracy of the system by 0.5° on the basis of the original direction finding algorithm.Finally,the system architecture and module composition of the system are introduced,including the array antenna,the main control platform of the board card and the user platform of the upper computer.At the same time,the realization of the error correction operation and the construction process of the sample library are explained.In the field environment,the system is applied to measure the actual signal,the system results are shown,and the direction finding accuracy is verified to reach the system index. |
