IMAGENEX DT101Xi, Техническое руководство

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The purpose of the patch test is to measure these errors and derive compensation values for Latency,
Pitch, Roll, and Yaw. The following table (Table 4-1) describes the parameters affected by the various
rotations and latency:
Parameter Affects
Latency Sounding position
Roll Sounding position and depth
Pitch Sounding position and depth
Yaw Sounding position
Table 4-1
A patch test should ideally be performed as follows:
•
Upon commissioning of a new system
•
After long periods of inoperability
•
Every time the MBES head has been removed and reinstalled
•
Whenever the MRU, heading reference or positioning system has been removed and reinstalled.
During data acquisition, the Surveyor should compare the overlapping outer beams of adjacent swaths and
to check for any trend of curvature upward or downward of each ping. This may suggest a sound velocity
issue.
Most MBES processing packages will have patch test functionality. Although not essential, it is recommended
to remove any legacy corrections in the navigation system prior to commencement of the patch test.
The data may be acquired in any order, but should be processed and applied as follows:
1. Latency
2. Apply latency offset, then process roll test
3. Apply roll, then process pitch test
4. Apply roll, then process yaw test