Mapping the Carrier Phase of a Propagating Wave by Wireless Two-Way Interferometry Scanned by a Mobile Robot

This study proposes a wireless high-precision carrier phase mapping system that removes the need for wired synchronization, which has been a significant limitation of conventional methods. The system achieves a root mean square error (RMSE) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\leq 0.2\,\mathrm {rad}$ </tex-math></inline-formula> across five trials. It employs wireless two-way interferometry (Wi-Wi) with 920 MHz modules, a mobile robot, and a high-precision positioning device to enable real-time and wide-area spatial sensing. To validate its effectiveness, mapping experiments were conducted over a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3\,\mathrm {m} \times 2\,\mathrm {m}$ </tex-math></inline-formula> area in an anechoic chamber. The system is particularly suitable for challenging environments such as large indoor facilities or elevated outdoor locations. This technology contributes to applications including wireless communication optimization and environmental sensing, especially in visualizing multipath, diffraction, and interference effects.