Attachment C_R.B23636.001.02.SEMP_final_lowres

5.0 Data Processing
The bathymetry data were processed in the QPS Qimera package using the following
workflow:
     •   Load logged DB files;
     •   Convert raw Range/Theta data to a geospatially corrected (XYZ) solution resulting in
         the creation of QPD files;
     •   Generate a Dynamic Surface;
     •   Load and apply processed positioning and orientation data from the Applanix POSPAC
         MMS software;
     •   Load and apply any extra SVP files from the Sontek Castaway CTD;
     •   Apply a weak Spline Filter to flag anomalous soundings as REJECTED;
     •   Manually clean (REJECT) any soundings deemed inconsistent with the river bed / sea
         bed or associated features that may be a hazard to navigation;
     •   Check Shallow and Deep Surfaces for any remaining anomalous soundings;
     •   Grid data at 0.5m and 1m bin sizes using a Weighted Moving Average algorithm with
         a Weight Diameter of 3.
     •   Export data products in a variety of formats.


Some minor modifications to this general workflow were implemented for selected lines and
areas (e.g., differing levels of Spline filtering or Beam Number filtering).
The single beam echo sounder (SBES) and land transect data were manually processed to
remove anomalous data spikes and then reduced to AHD. A comparison between SBES data
and the gridded swath bathymetry data was conducted prior to interpolation to allow
extraction of contours across the sand shoals inside the Noosa River entrance. Mean and
median differences between the two data sets was <10cm and deemed acceptable for the
survey objectives.




Figure 14: Results of cross check comparison between SBES point data and gridded swath bathymetry
                                               data.



15                               Noosa Council - Noosa River Survey                   20.06.2019