SonTek/YSI Argonaut-XR Technical Manual - HydroScientific West

SonTek/YSI
simplify post-processing corrections using data from an external temperature / salinity sensor.
Temperature is recorded with each sample, so post-processing corrections can be made using
data from either temperature mode. Post-processing corrections for sound speed errors are rarely
required; see the Argonaut Principles of Operation for details.
Averaging interval (s): (Enter value)
The Argonaut will accumulate samples internally for this period of time and then display and
store the mean sample. The standard deviation (accuracy) of the velocity data is inversely
proportional to the square root of the averaging interval (longer averaging times give lower
standard deviations). See the Argonaut Principles of Operation for more details. The acceptable
range of input values if from 10 to 3600 seconds.
The following two variables are present for the Argonaut SL and XR only, and are not available
with the Argonaut MD.
Cell begin (m): (Enter value)
Specify the location of the start of the measurement volume. The standard deviation (accuracy) of
the velocity data is inversely proportional to the square root of the measurement volume size (cell
end minus cell begin); larger measurement volume size gives lower standard deviation. See the
Argonaut Principles of Operation for more details. The acceptable range is from 0.5 to 14.8 m.
Cell end (m): (Enter value)
Specify the location of the end of the measurement volume. The standard deviation (accuracy) of
the velocity data is inversely proportional to the square root of the measurement volume size (cell
end minus cell begin); larger measurement volume size gives lower standard deviation. See the
Argonaut Principles of Operation for more details. The acceptable range is from 1.0 to 15.0 m.
The following variable is present for the Argonaut XR only, and is not available with the
Argonaut MD or SL (the menu item is not shown in Figure 14).
Dynamic boundary adjustment: (Multiple-choice)
This variable allows the Argonaut XR to automatically adjust the upper end of the measurement
volume based upon data from the pressure sensor. A setting of DISABLE turns off the dynamic
boundary adjustment and uses the fixed cell location parameters entered above. A setting of
INTEGRATED will use the fixed value of cell begin and will adjust the end of the cell to be as
close as possible to the surface. A setting of LAYERED will measure a layer whose thickness is
defined by (Cell End – Cell Begin), with the upper edge of the layer as close to the surface as
possible.
Coordinate system: (Multiple-choice)
This determines the coordinate system in which velocity data are displayed and stored. BEAM
gives velocity data as along-beam velocities (not commonly used). XYZ gives velocity data in a
Cartesian coordinate system relative to Argonaut orientation. ENU (for East-North-Up) reports
data in an instrument-independent Earth coordinate system; this requires that the Argonaut have
the optional compass/tilt sensor installed. The Argonaut MD and XR will typically use the ENU
coordinate system; the Argonaut SL will typically use the XYZ coordinate system. Refer to the
Argonaut Operation Manual for more details on coordinate systems.
Argonaut Software Manual (March 1, 2001) 47