4 – Operating Procedure
4-2
© Teledyne Limited
DPN 402197 Issue 7.1
4.1.3 Survey Requirements
During the early stages, the survey planning team will need to define the type of data required from the
survey:
❐
The 350 system can complete a quick and simple check on the track and depth of cover of a
target by making a series of widely spaced measurements.
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Alternatively, to work to the highest achievable accuracy, you might need to stop the ROV at
carefully specified intervals to perform accurate measurements on the target and to measure
the mean seabed level with a separate profiling system.
NOTE
The 350 system always delivers measurements of the highest achievable accu-
racy under the given conditions. The compromise that you need to make between
survey accuracy and operating speed arises from the need to manoeuvre and
measure the position of the ROV with greater precision when you demand a
sharper survey resolution.
4.1.4 Installation Requirements
Before starting a survey the survey planning team should define the installation requirements of the
350 system. They should consider:
❐
The type of ROV to be used and where the SEP and the coils will be mounted. The 350 system
is suitable for use on most types of ROV, including towed sleds. TSS can offer further advice if
necessary.
❐
Which communication method to use between the SEP and the topside computer. This will
depend upon the characteristics of the umbilical cable.
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Whether to use an altimeter or a rapid update profiler, and their location on the ROV.
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The type and capacity of data logger, and its connection and communication requirements.
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It is recommended that you generate a written or printed copy of the system configuration
before and again after the survey. This will be useful source of reference during the data anal-
ysis phase of the survey. This recommendation means you should arrange to connect a suita-
ble printer to the topside computer.
❐
The on board facilities for creating, displaying and recording video images from a sub-sea
camera mounted on the ROV. Consider using the video facilities to record the installation pro-
cedure of the 350 system.
4.2 Pre-dive Checks
This section describes a series of checks that you should perform on the 350 system before you
deploy the ROV and start the survey. Perform these checks carefully, noting any safety issues as you
do so: