SonTek, a Xylem brand
94 RiverSurveyor S5/M9 System Manual (February 2013)
Appendix C. MATLAB Export
The MATLAB output is ordered into a series of structures each containing their related parame-
ters and settings. The tables below describe each structure and their contents and it is current
as of version 3.60 of the RiverSurveyor Live software.
IMPORTANT NOTES:
• The term “sample” refers to a single vertical profile, taken over a period of 1 s.
• For the four parameters containing Velocity data (BottomTrack.BT_Vel, Sum-
mary.Mean_Vel, Summary.Boat_Vel, and WaterTrack.Velocity), the data is in the same
coordinate system that was selected in the software when the .mat file was exported.
For example:
o BT_Vel when exported in ENU coordinates will be:
1. East Velocity (i.e. velocity to the East)
2. North Velocity
3. Up Velocity
4. Difference Velocity (aka Error Velocity; the difference between measuring the vertical com-
ponent of the velocity from the two pairs of opposing beams)
o BT_Vel when exported in XYZ coordinates will be:
1. X Velocity
2. Y Velocity
3. Up Velocity
4. Difference Velocity
o BT_Vel when exported in Beam coordinates will be:
1. Beam 1
2. Beam 2
3. Beam 3
4. Beam 4
• GPS Altitude (from the GGA string) is based on a proprietary, non-published geoid, and
referenced to the bottom-center of the antenna.
The basic order of the root structures is as follows. For the Size Column:
• NS is the number of samples;
• NC is the maximum number of cells;
• If the structure contains another structure inside it, or the parameter is a scalar, the size
is NA.
Bottom Track Velocity, Depth and Frequency variables (includes
Vertical Beam).
GPS data and quality information.
The raw GPS data from either the internal GPS or an external seri-
ally connected GPS system. This data is stored in its raw format
with the same frequency that was output from the GPS. For exam-
ple, if the GPS outputs data at 10 Hz, then 10 GPS data values are
stored for each ADP sample.
System settings, edge information and profile extrapolation
Calculated discharge variables and the data used to compute
them.