Attachment C_R.B23636.001.02.SEMP_final_lowres

The POS MV Wavemaster is a user-friendly, turnkey system designed and built to provide
accurate attitude, heading, heave, position, and velocity data. POS MV is proven in all
conditions and is the georeferencing and motion compensation solution of choice for
hydrographic professionals.
A Fugro Marinestar navigation aiding subscription was activated as part of the Noosa River
survey, improving the real-time positioning of the system to less than 10cm horizontally and
vertically. The raw positioning and orientation data were post-processed in the Applanix
POSPac MMS software package to further improve horizontal and vertical accuracy to less
than 5cm.
Roll and Pitch accuracy from the IMU were approximately 0.03°, with Heave accuracy around
5cm. Heading accuracy post-calibration was around 0.1°.



2.3 Sontek Castaway CTD
To correct for refraction through the water column a sound velocity probe must be employed
during any hydrographic survey. The unit used for this survey was a SonTek CastAway CTD.
Designed for coastal profiling, the CastAway-CTD® incorporates a 6-electrode conductivity
cell, coupled with a fast response thermistor to provide highly accurate, high resolution CTD
measurements to depths of 100 m. The sound velocity accuracy derived from the CTD is 0.15
m/s. The unit has an in-built GNSS chip that captures the time and location of the CTD profile,
and BlueTooth capability for transferring data.




                                Figure 4: Sontek Castaway CTD.


During acquisition a comparison between the currently loaded SVP and the sound velocity
measured at the transducer head was monitored. If differences became too pronounced, then
another CTD cast was implemented. In water depths where relevant, a cast was made at a
minimum of the start, the middle, and the end of each survey day.


2.4 QPS and Chesapeake Acquisition, Processing, and Analysis
Software
The QPS QINSy package was used for data acquisition. The software has an excellent
reputation for robustness and stability and provided a number of useful online quality control
(QC) displays for data monitoring. QINSy logs all raw data in a proprietary DB format, and
geospatially corrected data (XYZ solution) in a QPD format. Options exist for exporting a
variety of non-proprietary formats.




                         Figure 5: Typical QC displays offered by QINSy.



7                              Noosa Council - Noosa River Survey                    20.06.2019