Optimal trajectory generation for draped AUV gravity surveys

Gravity surveys provide crucial data about the sub-seafloor structure, and this information is used to both localize and characterize geophysical phenomena. Obtaining this gravity data from submersibles provides superior measurements, both in terms of signal strength and spatial resolution, than conventional survey platforms such as surface vessels and satellites. However, performing gravimetry an AUV requires specialized trajectory planning algorithms that minimize acceleration noise. We develop an AUV simulation as a testbed for creating these algorithms, designed to model the behavior of the Sentry AUV at the Woods Hole Oceanographic Institution. We then investigate the signal and noise characteristics of AUV gravimetry and propose a novel trajectory planner and state estimator that mitigates multiple noise sources. The resulting simulation predicts a. 22 mGal standard deviation of signal noise, at a spatial resolution of 10 m, for a magma chamber with a 3.41 mGal gravity signature at depth, substantially better than other tested draped surveying techniques.