
Pathfinder DVL Guide
April
2018
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Page 27
Figure 14.
Short Pulse versus Long Pulse
A long Pulse is needed for the beams to ensonify (illuminate) the entire bottom all at once.
Water Tracking
Water tracking is used when the bottom is out of range or a reference velocity is desired. All TRDI DVLs
are configured to provide Water Tracking data. Water tracking is desirable in situations where the bottom
is not always within range of the DVL because of suspect Bottom Track data. The
config-
ures how often water track pings are sent. The number of Water Track pings per ensemble is dependent
(bottom pings per ensemble) and this command setting. Water track pinging is acti-
vated from the
. Use the BL command to set the location of the Water Track ping.
Required Conditions for Water Tracking
Water Track ping output data is available when both the BK (Water-Mass Layer Mode) and BP (Bottom-
Track Pings per Ensemble) instrument settings are nonzero values. The bottom must be at least the Mini-
mum Layer Size + Near Layer Bo 20% of the reported depth away from the transducer. The Far
boundary cannot exceed 80% of the range-to-bottom of the beam with the shortest altitude. If the bottom
comes up so that the Far boundary does not meet this requirement, then the Far boundary is automati-
cally adjusted to ensure this requirement is met, unless the minimum layer size cannot be maintained, in
which case the water track ping is skipped and the data is marked bad.
Figure 15.
Water-Mass Layer Processing