YSI SonTek RiverSurveyor, System Manual

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SonTek/YSI Inc
RiverSurveyor System Manual (May 1, 2007)
140
•
Check the cables between the computer and the ADP, or between the computer and the ra-
dio modem used with RiverCat systems. RiverCat users may want to connect their ADP di-
rectly to the computer; this could help determine if there are modem-related problems.
•
Repeat the procedure. Check
User Setup
(§
7.3.4
) settings. Try turning off the internal re-
corder or changing your profiling settings. If the problem persists, contact technical support.
The software jumped a few profiles or a group of profiles were received all at once.
There is a problem communicating with the ADP.
This may be more common with RiverCat systems when there are radio modem issues.
•
Check the radio modem connections. Make sure there is a clear line of sight between the
two radios. Also, check the LED status light on the radio modem connected to your com-
puter. The LEDs should be lit. If using Bluetooth radio modes, see
Appendix G
.
•
Check for improper grounding.
9.2. Bottom-Track Conditions
The system keeps losing bottom-track, or the BTrack indicator light keeps turning red.
The system is losing bottom-track.
If the ADP indicator light is also red,
RiverSurveyor is not receiving valid profile data.
Beam depth differentials caused by measuring near a vertical wall or in an area with a sharp
change in channel slope may cause an intermittent bottom-track failure.
Note : If you lose just a few bottom-tracks in your measurement section, RiverSurveyor
will take bottom-track data from the last good profile and use that data in computations
for the profile with the missing/invalid bottom-track information.
•
Reduce vessel speed and avoid making sharp turns with the vessel. It is good practice to
maintain the vessel at a speed no greater than the current speed, though environmental con-
ditions may preclude this.
•
Make sure the water depth does not exceed the maximum bottom-tracking depth for your
system. It is also possible that the water depth is lower than the minimum profiling depth.
Use
Table 3-1
to verify these conditions are within your system’s specifications.
•
Move the survey site to an area away from vertical walls and away from areas with sharp
changes in slope. These areas can cause large differentials in the individual beam depths.
•
An ill-defined riverbed, such as those found in very high suspended sediment environments
or areas with a large amount of vegetation on the bottom, can also cause the loss of bottom-
track. These conditions do not offer a sharp, clear density gradient for signal reflection.
•
See §
3.3.5
–
What are the limitations of bottom-track?
for more information.
•
It may be necessary to collect some raw data samples for analysis; contact SonTek Support .
The depths for each of the beams are very different.
The depths detected by each of the ADP’s beams are measuring different depths, which means
the system may be transecting an area with a sharp bottom gradient or slope.
•
Try to use a site with less severe changes in bottom depth. If this is not possible, try to re-
duce the vessel speed over these areas to get better bottom depth resolution.