Precision Measurement Engineering, Inc.
Precision Measurement Engineering, Inc.
The Mission tab of the SCAMP Control Dialog allows users to define
SCAMP’s mission. The Mission tab is shown below.
The user may select the profiling direction. See the Upwards Profiling or Downwards
Profiling sections elsewhere in this manual.
The user may define the starting conditions. The starting conditions are ‘OR’ed meaning that if any starting condition becomes true then SCAMP will start collecting data.
Begin Delay sets the amount of time (in seconds) that SCAMP will wait after SCAMP is awakened by the magnet before recording data. SCAMP will start recording data after this time unless another starting condition becomes true first.
Begin Depth sets the depth (in meters) that SCAMP will start
recording data. Each time SCAMP is awakened by the magnet it adjusts its depth channel
coefficients so that the current pressure results in a computed depth of 0 meters. After
this adjustment it samples the current depth about once per second. If the current depth
is greater than the Begin Depth entry data recording begins.
Acquire Scans sets the number of scans SCAMP will acquire before it stops recording data. SCAMP scans at 100 scans per second so if the number entered is divided by 100 the number of seconds of data recording is obtained.
The conditions should be defined so that data are recorded in an optimum way and so that the user can synchronize SCAMP’s motion through the water to the data recording.
In downwards mode, if near-surface measurements are desired, the Begin Depth condition is not very useful. The first reason is that SCAMP is unable to measure depth until the release end (containing the pressure transducer) is under water. Secondly, SCAMP’s depth channel has inaccuracies that can amount to roughly 25 cm. The best selection is to set Begin Depth to 1 meter, thereby insuring a start, but set time to something like 30 seconds or however much is required to get the SCAMP into deployment position after magnetic awakening. SCAMP indicates by activating its release screw that a profile is beginning and can be released at this time.
In downwards mode where deeper water is to be measured the Begin Delay condition should be set to insure sufficient time is available to deploy SCAMP and have it sink to the starting depth. The Begin Depth should be set to the starting depth desired. Do not set Begin Time to a huge value since it is important that SCAMP begin recording data in case it never reaches the desired starting depth. If SCAMP does not begin (and end) recording data it cannot be magnetically awakened for a new profile. See the Aborting a Profile section in this manual.
In upwards mode the Begin Delay condition should be set to give sufficient time for SCAMP to be deployed and reach the Begin Depth. Do not set Begin Time to a huge value for the same reason described in the paragraph above.
If a start from the bottom is desired, Begin Depth should be set to a value larger than the depth of the bottom, and Begin Delay set to a value that will allow SCAMP to reach the bottom. SCAMP will then descend to the bottom but not reach the Begin Depth, wait out the remaining delay, and release its weight for ascent.
In all cases data recording must be ended by setting the Acquire Scans parameter. When travelling at 10 cm/sec SCAMP acquires 1000 scans per meter. Velocity will vary so Acquire Scans should be set to give a few meters extra data recording beyond the length of data recording desired in the water column.