Triton Navigation - Manual (Page 12)

Page 9
BATHYMETRY (multibeam, singlebeam, & interferometric data):
 Amount: Bathymetry data generally requires very little processing of the navigation
data. Modern multibeam and singlebeam systems include very precise high
frequency GPS data. As long as the vessel position and motion data are properly
captured and recorded, then changing the ping location by smoothing the navigation
or the instantaneous heading by applying CMG or is not a good idea! For most
bathymetry data, just one iteration is enough. However if there are areas of bad
navigation in the survey due to overhead obstructions, it may be best to process
these lines individually allowing the user to remove the position noise and get more
accurate positions for each ping in these lines while preserving the good navigation
in the rest of the survey.
 Settings: Using a boxcar Window Width = 12 is generally good, with the Navigation
Source = Ship and Heading Source = Ship . The Speed Filter is great for removing
spikes in the data and needs to have the speed range set to remove ping positions
that require too fast a speed to get there and back to the next ping location.
 When: Unless there are known areas with poor GPS quality in the survey, monitoring
navigation processing with beamlines is not needed for bathymetry data and using
the Bathy Wizard for navigation processing is best. Note that it is always best to
turn on all beamlines before processing the bathy navigation to check for problem
navigation areas.
SUBBOTTOM:
 Amount: Subbottom data generally requires very little processing of the navigation
data, however for systems with low frequency GPS signals it may take a few
iterations to spread the shot points out along the survey track line.
 Settings: Using a boxcar Window Width = 12 is generally good. For towed
subbottom profilers, select the Navigation Source = Sensor and Heading Source =
Sensor . The Speed Filter is great for removing spikes in the position data. Note
that for subbottom data, this is where layback is applied.
 When: Processing navigation for subbottom data always should be done first before
viewing the profiles from the subbottom navigation file tree. Be sure to check the
box for
Check Intersections !