Valeport SWiFT, Руководство по эксплуатации

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Important Information
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©
2021
– Valeport Ltd
There are three controlling parameters that define an Up Cast or Down Cast:
Trigger Depth: Trigger point at the surface
(default = 1m)
Depth Increment: The depth increment at which profile data points are recorded
(default = 0.1m)
Trigger Step: Trigger point at depth
(default = 1m)
At each GPS fix a pressure reading is recorded and set as the system Tare value. The Tare
pressure is recorded in the Header data of each file, it will be applied to any depth observation
recorded.
Before deployment ensure you have a valid GPS fix (the GPS symbol light will be solid green) and,
therefore, a Tare pressure setting to apply to the data. The SWiFT will continually update its GPS
fix until deployed into the water. GPS and all LEDs are disabled at ~2m depth to conserve power.
If no GPS fix is acquired before the SWiFT is deployed, the profile data will still be recorded but
with a position of 999,999.
On deployment, the following sequence will occur:
•
Last GPS fix and Tare observation recorded.
•
Down Cast
-
Will start recording values at programmed Trigger Depth e.g. 1.00m
-
Records
data at each Depth Increment e.g. 0.10m to depth
-
Stops recording when the Trigger Step is sensed e.g. 1.00m upwards
(should be set to greater than the local sea and swell)
-
Data file closed
-
Return to surface ready for new cast or download profile data.
-
Multiple casts can be recorded between downloads.
•
Up Cast
-
Will start recording when the Trigger Step is sensed e.g. 1.00m upwards at the required depth
(should be set to greater than the local sea and swell)
-
Records values every Depth Increment e.g. 0.10m on the up cast towards the surface
-
Stops recording when the Trigger Depth is sensed e.g. 1.00m
-
Data file close
-
Return to surface ready for new cast or download profile data.
-
Multiple casts can be recorded between downloads.
•
To obtain a GPS fix, the SWiFT needs to be above the water surface and have clear visibility
of open sky. A hot fix is usually obtained in less than 30 seconds. A cold fix, for example,
after a long time switched off, in a new part of the world, or after a firmware update, may take
a few minutes. If the sky view is restricted, obtaining a fix will take longer and the accuracy
reduced.