p-rock (probability of rock) grids from the Darwin Harbour 2011 Marine Survey (GA0333)

This dataset contains probability values of rocky/hard seabed (multibeam angular backscatter response derived product) from seabed mapping surveys in Darwin Harbour. The survey was undertaken during the period 24 June to 20 August 2011 by iXSurvey Australia Pty Ltd for the Department of Natural Resources, Environment, The Arts and Sport (NRETAS) in collaboration with Geoscience Australia (GA), the Darwin Port Corporation (DPC) and the Australian Institute of Marine Science (AIMS) using GA's Kongsberg EM3002D multibeam sonar system and DPC's vessel Matthew Flinders. The survey obtained detailed bathymetric map of Darwin Harbour. Refer to the GA record ' Mapping and Classification of Darwin Harbour Seabed' for further information on processing techniques applied (GeoCat: 79212; GA Record: 2015/xx)

Simple

Identification info

Date (Publication)
2015-01-01T00:00:00
Citation identifier
Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/83950

Cited responsible party
Role Organisation / Individual Name Details
Author

Siwabessy, J.

 1
Point of contact
Role Organisation / Individual Name Details
Custodian

EGD
Owner

Commonwealth of Australia (Geoscience Australia)
Custodian

Commonwealth of Australia (Geoscience Australia)

 Voice
Topic category
  • Environment

Extent

N
S
E
W


Maintenance and update frequency
As needed

Resource format

Title

Product data repository: Various Formats

Website

Data Store directory containing the digital product files

Data Store directory containing one or more files, possibly in a variety of formats, accessible to Geoscience Australia staff only for internal purposes

Keywords

  • Marine Data

  • Backscatter Grid

Theme

  • backscatter

Theme

  • multibeam

Theme

  • marine survey

Theme

  • marine environmental baselines

Keywords

  • AU-NT

Australian and New Zealand Standard Research Classification (ANZSRC)

  • Marine Geoscience

Keywords

  • Published_External

Resource constraints

Title

Creative Commons Attribution 4.0 International Licence

Alternate title

CC-BY

Edition

4.0

Website

http://creativecommons.org/licenses/

Access constraints
License
Use constraints
License

Resource constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified
Language
English
Character encoding
UTF8

Distribution Information

Distributor contact
Role Organisation / Individual Name Details
Distributor

Commonwealth of Australia (Geoscience Australia)

 Voice
OnLine resource

File download

Download the file

Resource lineage

Statement

The backscatter data were processed using CMST-GA MB Process v10.10.17.0 software on the National Computational Infrastructure (NCI) supercomputer at the Australian National University.


In the process of removing the angular dependence from the backscatter for a consistent backscatter strength across the swath in various incidence angles (for a homogeneous seafloor), the angular backscatter response was calculated in a 1° bin of incidence angle and averaged within the sliding window. The angular backscatter response is an intrinsic property of the seafloor, illustrating that the backscatter strength changes with the angle of incidence and is dependent on substrate type.


The angular backscatter response curve data was analysed to produce a dataset indicating the probability of seabed hardness. The underwater video-derived hardness classifications were first used with existing seabed hardness data from DLRM to identify known areas of "rocky" seabed. The angular backscatter response curves were then extracted from the identified "rocky" areas and an average of the angular backscatter response curves was calculated. This was completed to determine a reference curve of "rocky" seabed. This curve was used as a reference and compared to all other angular backscatter response curves using the Kolmogorov-Smirnov goodness of fit test to estimate the probability of the "rocky" seabed (p-rock). Finally, the Inverse Distance Weighted interpolation technique was used to produce a continuous layer of the p rock for the whole study area.

Hierarchy level
Dataset
Description

Legacy product, source data not available.

Extent

N
S
E
W


Metadata constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified

Metadata

Metadata identifier
urn:uuid/1d77f2d0-d070-e6de-e053-10a3070ab1fd

Title

GeoNetwork UUID

Language
English
Character encoding
UTF8
Contact
Role Organisation / Individual Name Details
Point of contact

Commonwealth of Australia (Geoscience Australia)

 Voice

Type of resource

Resource scope
Dataset
Name

dataset

Alternative metadata reference

Title

Geoscience Australia - short identifier for metadata record with

uuid

Citation identifier
eCatId/83950

Metadata linkage

https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/1d77f2d0-d070-e6de-e053-10a3070ab1fd

Date info (Revision)
2018-04-20T06:03:53
Date info (Creation)
2015-08-17T00:00:00

Metadata standard

Title

AU/NZS ISO 19115-1:2014

Metadata standard

Title

ISO 19115-1:2014

Metadata standard

Title

ISO 19115-3

Title

Geoscience Australia Community Metadata Profile of ISO 19115-1:2014

Edition

Version 2.0, September 2018

Citation identifier
https://pid.geoscience.gov.au/dataset/ga/122551

 
 

Spatial extent

N
S
E
W


Keywords

backscatter marine environmental baselines marine survey multibeam

Provided by

Access to the portal

Associated resources

Not available