Dataset TITLE

Bathymetry of Cato, West and Birds Island (Coral Sea Queensland)

The multibeam bathymetry was acquired by the following surveys:

Data Quality LINEAGE

The grids were compiled from the following surveys:

# Survey Name Vessel Name Multibeam System Institution Start Date End Date Start Port End Port

1 GA-0270_SS052004 RV_S_Surveyor EM300 CSIRO 03/5/2004 27/4/2004 Sydney Noumea

2 GA-0274_SS022005 RV_S_Surveyor EM300 CSIRO 25/01/2005 20/2/2005 Bundaberg Cairns

3 GA-0295_SS012005 RV_S_Surveyor EM300 CSIRO 07/01/2005 23/1/2005 Brisbane Bundaberg

4 GA-1149_WEST05MV RV_Melville Seabeam 2000 (12 kHz) SCRIPPS 19/5/1994 25/6/1994 Papeete Brisbane

5 GA-2306_EW0201 RV_M_Ewing Atlas hydrosweep DS LDEO 31/1/2002 14/2/2002 Hobart Apra,Guam

6 GA-2385_MR03k03Leg2 RV_Mirai Seabeam 2112 (12 kHz) JAMSTEC 01/7/2003 30/7/2003 Nakagusuku Brisbane

7 GA-2418_SO190 RV_Sonne EM120 (12 kHz) IFM_GEOMAR 25/12/2006 09/1/2007 Darwin Wellington

8 GA-4378_MR0901Leg2 RV_Mirai Seabeam 2112 (12 kHz) JAMSTEC 21/05/2009 19/06/2009 Papeete Brisbane

9 GA-4379_MR0901Leg3 RV_Mirai Seabeam 2112 (12 kHz) JAMSTEC 19/06/2009 02/07/2009 Brisbane Moji

10 GA-4398_SS2012v06 RV_S_Surveyor EM300 CSIRO 26/10/2012 10/11/2012 cairns Brisbane

11 GA-4400_SS2012v07 RV_S_Surveyor EM300 CSIRO 23/11/2012 19/12/2012 Brisbane Brisbane

This dataset was compiled and processed by Michele Spinoccia, using CARIS HIPS & SIPS ver 7.1.2.

1. First a vessel configuration file was created for each vessel where the co-ordinates of the motion sensor and DGPS antenna and patch test offsets were recorded.

2. A new project was then created and the vessel configuration file was attached to the project file.

3. The raw swath sonar data, in raw.all format, for each line was then imported into the project and the vessel information assigned to the data.

4. The motion sensor, DGPS and heading data were then cleaned using a filter that averaged adjacent data to remove artifacts.

5. Different sound velocity profiles data for each block were attached to the corresponding raw swath sonar data files to correct the depths for changes in the speed of sound through the water column.

6. Then a new blank field area was defined that specified the geographic area of study and the co-ordinate system used. The co-ordinates for the study areas were WGS84 UTM-56S.

7. The data was cleaned by applying several filters that removed any remaining spikes in the bathymetry data using user defined threshold values. A visual inspection of the data for each line was then undertaken where artifacts and noisy data not removed by the filtering process were removed manually using Swath and subset editors modules of the Caris HIPS/SIPS software.

8. All the data for each bathymetric, motion sensor, DGPS, heading, tide and sound velocity profile data were merged to produce the final processed data file. A weighted grid of the processed data was then created for each Block.

In GA the tide was applied to the grid to correct for tidal variations and velocity corrections were performed to correct for different artifacts and mismatches.

9. The processed data was finally exported as grids soundings or false colored images for presentation and reporting and as final processed data in in ASCII XYZ as well as geotif formats of 50m resolution.

10-Using CARIS Base editor 4.0 the grids were exported as ESRI ASCII grid, then imported into ARC catalogue/info to create a raster file for the entire survey.