Miniaturized polarization compass based on a customized vortex retarder and a mini-camera

We have designed and implemented a miniaturized polarized skylight compass (MPSC) to address the challenges such as size, cost, and computational demands in current polarized skylight navigation systems. The MPSC utilizes a customized vortex retarder and a micro-scale camera as the spatial polarization modulating and image-grabbing elements, combined with an STM32 embedded chip to process the image efficiently. A lightweight radial integration algorithm is employed to realize rapid and precise heading angle output. The performance and accuracy of our MPSC have been validated through both static and dynamic experiments. Experimental results demonstrate that the MPSC achieves an output rate of 10 Hz, with a root mean square error of 0.04° under the static turntable experiment and 0.14° on a dynamic unmanned vehicle platform. The prototype is compact, measuring 45mm×35mm×30mm, and lightweight at 30 g. This work highlights the MPSC's potential as a robust and practical navigation solution for unmanned platforms, particularly in GPS-denied environments, marking a significant advancement in the field of polarized skylight navigation.