Noggin
13-Survey & Map Mode
83
The odometer should be periodically re-calibrated to ensure accuracy. The procedure for re-
calibrating the odometer is described in
13.5.2: p.120
.
13.2.7.1 Backup Arrow to Pinpoint Target Positions
The odometer also allows the user to stop the Smart System in the middle of a survey line and
back up. When this is done, an arrow and vertical line appear on the data image and move back
along the image as the system moves backwards (
Figure 13-1
). This makes it possible to
correlate a target in the data image to an exact location on the ground. Once the arrow lines up
with the target, mark the ground at the center point of the Noggin.
When the system is moved forward again to continue with the survey, the Smart system does not
start collecting data again until you reach the position where you stopped at. This feature is
useful for producing a continuous data image even if the system is backed up during the survey
line.
Note that it is not possible to back up and have the arrow indicator move more than one screen.
The physical position corresponding to the Back-up arrow is the center of the Noggin.
13.2.7.2 Skipping Traces by Moving too Fast
On the lower part of the data acquisition screen, beside the current total number of traces
collected is the total number of traces skipped.
If the Smart System is being used with the odometer and is moved too quickly for the Noggin
system to keep up, traces are skipped and the quality of the survey is reduced. The skipped
traces do not actually create gaps in the data but rather, the last trace that was collected properly
is repeated. The Skipped Traces number displays the total number of skipped traces (
Figure 13-
1
). If this number exceeds 0 this is due to moving the system too quickly.
If the system is moved too fast, after the data survey line is complete, the DVL will indicate the
total number of traces that were “skipped”. If more than 10% of the traces in the survey line were
skipped, the user then has the option to Autofix the data. The Autofix process replaces any
repeated traces in the data with interpolated traces. While this process does not solve the
problem of skipping traces, it will make the data traces look less “blocky” when plotted.
If the number of traces skipped is a significant percentage of the total number of traces collected,
i.e. 10% or more, the operator should slow down, decrease the number of Stacks (
13.3.1.5: p.96
)
or reduce the Depth setting (
13.3.1.1: p.94
).
Содержание Noggin 100
Страница 1: ...User s Guide Copyright 2012 Sensors Software Inc 2011 00022 02 Noggin ...
Страница 2: ......
Страница 4: ......
Страница 8: ......
Страница 17: ...Noggin 2 Noggin Components 3 Figure 2 3 Noggin 100 components ...
Страница 156: ...Appendix D Instrument Interference Noggin D 2 ...
Страница 158: ...Appendix E Safety Around Explosive Devices Noggin E 2 ...
Страница 162: ...Noggin G 4 ...