Teledyne RD Instruments SENTINEL V REAL-TIME, Руководство по эксплуатации

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September
2017 Sentinel V SC and RT Operation Manual
Page 196
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
BX – Maximum Search Altitude
Purpose Sets the maximum search altitude in bottom-track mode.
Format BXnnnnn
The BX command works only without the # sign.
Range See Table 23 below
Default See Table 23 below
Set BX to a depth slightly greater than the expected maximum depth.
Description This command sets the maximum altitude, in dm, that will be searched when searching for
the bottom, and is dependent on the system frequency. In addition, there is an associated
minimum search altitude, which is not set by command, but is also frequency-dependent.
Note that these limits are for the ping configuration, and that the system may acquire and
track the bottom at altitudes that are slightly beyond these limits as shown in Table 23.
Table 23. Maximum Search Altitude
Frequency (kHz) Maximum Search Altitude (dm) / (Default) Minimum Search Altitude (dm)
983.04 450 3
491.52 1250 3
307.20 2400 6
Example If the maximum depth in the deployment area is 20 meters (200 decimeters), set BX to a
value slightly larger than 200 dm; say 210 dm, instead of the default 450 dm. Now if the
Sentinel V RT loses track of the bottom, it will stop searching for the bottom at 210-dm (21
m) rather than spend time searching down to 450-dm (45 m).
The BX command limits the search range for bottom tracking. If the Sentinel V RT loses lock
on the bottom, it goes into search mode, which iteratively searches increasing ranges until
either the bottom is found or the maximum range is reached, and then the process starts
over at the minimum range. The BX command will prevent the Sentinel V RT from searching
to ranges beyond the BX range value, and can result in shorter search cycles if the bottom is
known to be within this range.
In addition to limiting the search range, the BX command indirectly limits the bottom track
range. While this does not prevent the Sentinel V RT from bottom tracking to ranges beyond
the BX range, use caution in setting this command to less than the expected maximum depth
as the Sentinel V RT will be less likely to hold a lock on the bottom if there is any slope
beyond the BX range.