Klein Marine Systems, Inc. HYDROCHART 3500, Operation And Maintenance Manual

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Bathymetric System Calibration and Patch Test
3-11
14.
Verify
that the Sonar Head Unit is transmitting by viewing the output pulse in the
Scan window. Also check that navigation data are being displayed in the
Information window.
15.
Perform a rub test on the port and starboard transducers to confirm that the
receivers are operating properly. Do this test by vigorously rubbing each
transducer one at a time while observing for returns in the Sonar Viewer
window.
16.
Turn off the PC and the TIU.
3.10 Bathymetric System Calibration and Patch Test
For new installations it is recommended that a patch test be performed to quantify
any residual biases in the installation which could affect the accuracy of the
bathymetry data. The tests use a series of reciprocal lines run at different speeds,
depths and bottom slopes as inputs to compute the following residual biases:
• Positioning/Latency error
• Pitch bias
• Yaw bias
• Roll bias
For the tests outlined below, all acquired data can be batch processed using the
Klein Batch Processing GUI application and subsequently analyzed using a
third-party application, such as Caris and Hypack. For details regarding the data
interface/conversion, see the Help file in the Klein Batch Processing GUI
application. The tests are listed in the recommended order in which they should be
processed. For example, latency should be processed before pitch, which is
followed by yaw, and then roll. This will eliminate the effects of uncorrected errors
on the other axis.
Following are a few available references containing information about the
calculation procedures for these offsets and errors:
• "Field Procedures for the Calibration of Shallow Water Multibeam
Echo Sounding Systems," Andre Godin, Canadian Hydrographic
Service, Halifax, Nova Scotia, Canada, 1996.
• "US Army Corps of Engineers, Engineer Manual EM-1110-2-1003,"
Hydrographic Surveying, Jan-02.