Abstract:A multi-level data processing method is proposed to effectively improve the direction finding accuracy of a multi baseline interferometer direction finding system, addressing issues such as ambiguity resolution errors and low direction finding accuracy caused by measurement noise and system errors. This method adopts the spatial baseline method with strong anti-interference ability, moderate complexity, and easy engineering implementation, and focuses on data processing before and after resolving ambiguity. In response to the mutual correlation and influence of phase difference data between baselines in the process of resolving ambiguity, the median filtering algorithm was selected to effectively filter out noise while preserving the original information of the data as much as possible, thereby effectively improving the accuracy of ambiguity resolution and direction finding. To improve the reliability of direction finding data, abnormal values were removed from the data again after direction finding calculation. Design FPGA+DSP hardware platform and complete the engineering of multi-level data processing method based on DSP chip TMS320C6713. The measured data shows that under the condition of a miniaturized antenna array with a longest baseline of only about 10 wavelengths, when the Root Mean Squared Error (RMSE) of the input phase difference data is 3.4°, the ambiguity resolution is correct, and the angle measurement RMSE can be controlled within 0.1°, the data processing speed can reach 100Hz. This direction finding data processing method effectively improves the accuracy rate of ambiguity resolution, with fast processing speed, high direction finding accuracy, and strong engineering practicality.
