YSI SonTek RiverSurveyor, System Manual

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SonTek/YSI Inc
RiverSurveyor System Manual (May 1, 2007)
100
You can zoom in and out on the display by clicking the
Zoom In
/
Zoom Out
buttons, or
by pressing the
Z
key (zoom in) and
Shift+Z
key (zoom out).
The
Track Window
can also display waypoints. Waypoints are used for navigation and assist the
vessel pilot to follow a pre-determined course. See §
7.5
for detailed information about way-
points. Moving the mouse cursor over a waypoint will show any comments that may have been
entered for the selected waypoint.
7.2.5. Data Quality Window
The
Data Quality Window
(
Figure 7-11
) can display a variety of variables than can be used as in-
dicators of the quality of the velocity data (and therefore, discharge data).
The desired variable (listed below) that you wish to monitor can be displayed by right-clicking
on the axis to the left of the graph, and then selecting the variable. Double-click the axis to
change the scaling of the variable. The data quality variables are:
•
Data Quality Index (DQI)
– The DQI indicates the quality of the discharge data. Low values
(typically below 5 units) indicate good-quality data. Data “spikes” indicate poor-quality or
missing data (usually caused by a loss of bottom-track or too few cells). See following
Note .
•
Boat Speed (Bs)
– This temporal data should indicate a relatively steady speed with only
small changes in magnitude.
•
Water Speed (Ws)
– This temporal data typically shows lower magnitudes along the
start/end sections and progressively increasing magnitudes toward the center section of the
survey area.
•
Boat/Water Speed (Bs/Ws)
– As described in §
6.5
, it is good practice to keep vessel velocity
less than the average water velocity under most conditions. The
Bs/Ws
ratio is a good vari-
able to monitor during data collection. See the following Note .
•
Heading
– This temporal data should show a relatively constant value with only small
changes in magnitude from adjacent profiles.
•
Pitch
/
Roll
– This temporal data should show pitch/roll values to be relatively constant and
small in magnitude (typically less than 5° is preferable).
Note: The indicators for the
Data Quality Index
and the
Boat/Water Speed
ratio are dis-
played as bars of different colors depending on their value. These colors are used as
visual indicators (or alerts) that you can easily monitor during data collection. The col-
ors can be used to indicate three data conditions — good (black), warning (orange),
alert (red). To change the colors, use
File|Screen Colors|Data Quality Colors
. To set the
warning/alert thresholds for these variables, use
File|Configuration|Data Warning
Thresholds-Change
.
Figure 7-11. Data Quality Window