A Low-Cost Polarimetric Radar System Based on Mechanical Rotation and Its Signal Processing

Advancements in polarimetric information have led to the utilization of polarimetric radar in numerous fields, particularly in target detection and recognition. However, the stringent requirements for consistency and isolation of the polarization channels result in system complexity and high costs, posing significant barriers to the widespread adoption of polarimetric radar. To overcome the aforementioned challenges, a low-cost polarimetric radar system is proposed based on mechanical rotation, namely, mechanical rotation polarimetric radar (MRPR). First, the method of achieving variable polarization in the proposed system is introduced. The transmitted polarization is altered by continuously rotating the feed source, the polarization grid, or the metal irises, effectively circumventing technical challenges. Taking the mechanical rotation of the source feed as an example, a unique signal processing method is proposed to obtain the target polarization scattering matrix. This method enables the MRPR to possess the capability of obtaining fully polarimetric information with a low-cost system design. Subsequently, the influences of the feed source position, target Doppler information, reflection proportion coefficient, pulse number, and rotational speed on the MRPR are discussed. In addition, the methods for estimating target Doppler information and achieving coherent accumulation are presented. Owing to its rotation characteristics, the MRPR demonstrates stable performance in target detection across different target orientations. Moreover, the potential super-resolution ability of the MRPR is revealed by selecting specific rotation angles. Finally, simulated and practical experiments demonstrate the theoretical correctness and superiority of the MRPR.