Bm - Bottom Track Mode; Figure 43. Water-Mass Layer Processing; Table 15: Bm4/Bm5 Minimum Tracking Depths - Teledyne WORKHORSE Operation Manual

WorkHorse H-ADCP Operation Manual

BM - Bottom Track Mode

Purpose Sets the Bottom Track mode.
Format BMn
n = 4, 5, (see description)
Range
Default BM5
Recommended Setting. The default setting for this command is recommended for most applications.
Description See below
Bottom Track Mode 4
Bottom Track Mode 4 uses the correlation side-peak position to resolve velocity ambigui-
ties. It lengthens the lag at a predetermined depth to improve variance.
Bottom Track Mode 5
Bottom Track Mode 5 is similar to Bottom Track Mode 4, but has a lower variance in
shallow water by a factor of up to four. In very shallow water at slow speeds, the variance
is lower by a factor of up to 100. Bottom Track Mode 5 also has a slightly slower ping rate
than Bottom Track Mode 4.
Bottom Mode 5 (default setting) will shift to Bottom Mode 4 if the conditions warrant.
The H-ADCP limits searching for the bottom to the value set by the BX-command (max
bottom tracking altitude) + 0.5 transmit length. This allows a faster ping rate when the
bottom altitude is close to the BX-command setting.
Table 15: BM4/BM5 Minimum Tracking Depths
Frequency (kHz)
300
600
Figure 43. Water-Mass Layer Processing
BM4/BM5 Minimum Tracking Depths (m)
1.5
1.0
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
May 2015
Page 135