Coastal Hazard Assessment · MCU25/0087

SandMap – Report of Survey for Sunshine Beach Profiles



                  RTK post processing
           The Septentrio Altus NR3 RTK GNSS unit utilised for both the beach fieldwork and as a
           positioning system for the CEE ECHO single beam remained in RTK fixed mode at all times
           throughout the survey. Alerts were set up to warn of any dropout situation however this did
           not occur during this survey. No post processing of GNSS data was required.

                  Required precision
           A total horizontal uncertainty of plus or minus 0.5m at a 95% confidence level was determined
           for this project. Horizontal accuracy checks to established survey control as detailed below
           proved the NR3 GNSS system was well within this specification during the project. Overlap
           was achieved between land based RTK GNSS data and sonar soundings and all vertical
           differences were less than 0.1m while horizontally the profiles met within 0.5m.

                  Rejection criteria for position data
           Filters were used to ensure minimum satellite count was 6 and a satellite elevation mask of
           15° was set. During the project the satellite count was rarely below 20, due to the system using
           4 constellations. This ensured a maximum HDOP of 4 and maximum VDOP of 2 was easily met.
           The maximum age of corrections was 3 seconds.

           Horizontal control
           For this project, a Smartnet Australia GNSS solution was utilised for the survey using the base
           station located at Noosa. The Regulation 13 certificate for this base station can be found in
           Appendix B.
           Initial checks carried out using an Altus NR3 quad constellation RTK GNSS unit against local
           marks PSM 18419 and PSM 108353 with low horizontal uncertainties, produced good results
           confirming suitable accuracy of the SmartNet base station solution for use over the survey
           area.
           The check results can be found in Appendix A: Survey Control Checks.

           Vertical datums
                  Marine datum
               All reported depths are referenced to Australian Height Datum (AHD).

           Connection to vertical control
           For this project, a Smartnet Australia GNSS solution was utilised for the survey using the base
           station located at Noosa. The Regulation 13 certificate for this base station can be found at
           Appendix B.
           Initial checks carried out using an Altus NR3 quad constellation RTK GNSS unit against local
           marks PSM 18419 and PSM 108353 with low vertical uncertainties, produced good results


Rev. no.    Doc No.                                        Version Date          Doc Approver
  1         P0100-20251020                                 20/10/2025            Rod Tansley                        Page 8 of 20

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