Passive Acoustic Ranging for Helicopter Altimetry on Mars, Venus, and Titan

Passive acoustic altimetry on manned or unmanned aerial vehicles (UAV) provides a low power solution in low visibility operational conditions. The technology uses microphones to calculate the periodicity of acoustic waves generated by the rotor and reflected from the surface to infer the height of the UAV. This paper explores the application of this technology on planets with significant atmospheres to fly UAVs. We show that the signals remain detectable in the presence of background noise and acoustic absorption. Results from simulations conclude that the passive acoustics ranging technology can be applied to Mars, Venus, and Titan within a reasonable near-surface operating altitude.