Odom ECHOSCAN, Руководство пользователя

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04/26/02 31
Revision 1.11
MULTIBEAM CALIBRATION
There are several ways to calibrate the ECHOSCAN Multibeam. These include:
A standard “bar check”, a combined calibration with a single beam echo sounder,
a combined velocimeter and echo sounder calibration, and a “Patch Test”.
Bar Check
A standard “bar check” involves lowering the bar target below the
multibeam transducer and following a calibration procedure similar to that
prescribed for single beam echo sounders (See Figure 18). Note: With
the ECHOSCAN, it is not necessary to lower the bar directly beneath the
transducer. It may be lowered on the opposite side of the vessel. The
procedure for bar checking is the same with exception of the
Channel #
which must be set to monitor the proper beam.
Referencing to a Single Beam Echo Sounder
If the multibeam system is configured to operate with a single beam echo
sounder such as the Odom ECHOTRAC, it is possible to perform a normal
“bar check” on each simultaneously. NOTE: Draft and Velocity
corrections may vary between the two units due to slight differences in the
position of the receivers, mechanical response, rise time delay, etc..
There may also be a slight delay from the time the echo sounder
generates the “ping” command until the time ECHOSCAN begins the
multibeam sounding cycle. In any case, adjust both systems according to
the instructions in Figure 18.
Combined Velocimeter and Single Beam Calibration
This method requires the single beam echo sounder and the ECHOSCAN
be “bar checked” only once to establish
Draft corrections. Assuming the
transducer mount remains unchanged and that the transducer is always
lower to the same position, there may be no need to repeat the calibration.
A velocimeter is used to periodically measure the speed of sound in water
and this value is entered into the ECHOTRAC, ECHOSCAN, and the
multibeam software.