https://www.ri.cmu.edu/pub_files/pub4/fairfield_nathaniel_2007_1/fairfield_nathaniel_2007_1.pdf https://www.ri.cmu.edu/pub_files/pub4/fairfield_nathaniel_20...

https://www.ri.cmu.edu/pub_files/pub4/fairfield_nathaniel_2007_1/fairfield_nathaniel_2007_1.pdf https://www.ri.cmu.edu/pub_files/pub4/fairfield_nathaniel_20... In May 2005, the DEPTHX team lowered a 32-sonar probe, called the DropSonde, into Zacaton to a depth ´ of 200m (Figure 1) (Fairfield et al. 2006). A similar probe, called the Digital Wall Mapper (DWM) was used in 1998-1999 to map several kilometers of the Wakulla Springs cave system in Florida (Stone et al. 2000). The DWM was a diver-driven sensor sled, and the DropSonde was simply lowered on a cable from a barge. Both probes were based around a ring laser gyro IMU, two depth sensors, and a ring of 32 pencil beam sonars arrayed radially The first author is a principal engineer at Waymo and has been at google since 2009.