Design and Empirical Validation of a Low-Cost Outdoor mmWave Altimetry Test Bench for UAS

The increasing adoption of unmanned aerial systems (UAS) in diverse urban applications necessitates reliable and precise altimetry solutions for situational awareness and landing safety. Despite significant advancements in the realm of waveform design and signal processing, empirical validation of millimeter wave (mmWave) Frequency Modulated Continuous Wave (FMCW) waveforms for altimetry use case remains a critical gap in literature. This study argues the necessity of empirical validation of candidate FMCW waveforms by proposing an inexpensive and practical outdoor test bench. The multipath propagation model for the said test bench is presented along with a simplified testing methodology suitable for implementation on contemporary mmWave automotive radars. The specifics of the test bench are deliberated where a flat concrete wall with a sufficiently large surface area is employed as a static target. The underpinnings established by this body of work shall serve dynamic testing on a drone platform against various terrain types in the next phase of research. The experimental results demonstrate the potential of practical use of mmWave altimetry on UAS in urban deployment.