weeks of intensive AUV experimentation sponsored by the Office
of Naval Research and held in Keyport, Washington in
June 2005. The key technical advance for these experiments
was the shift to using one-way acoustic range measurements
with the WHOI modems, based on accurate time synchronization
provided by GPS. We also experimented with different
acoustic ranging configurations, alternating between transmission
of short-packets for frequent ranging and longer packets
encompassing data transfer. Figure 6(a) shows a photo of the
four MIT Scouts deployed at AUVFest and Figure 6(b) shows
the trajectories of three Scouts doing formation keeping and
acoustic ranging during a typical experiment. Figures 6)(c)
through Figures 6)(e) show a comparison of one-way acoustic
range measurements with inter-vehicle distance measurements
derived from GPS for this run. These data sets have been postprocessed
with an MLBL algorithm to derive the trajectory of
the lead vehicle in relation to the two following vehicle, as
shown in Figure 6(f). Further algorithmic details will be published
in a forthcoming report.