Brief description
The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose.This radiometric thorium grid has a cell size of 0.0004 degrees (approximately 40m) and shows thorium element concentration of the Kingoonya (Reedy Lagoon), SA, 1987 (87SA02) (74lu) survey. The data used to produce this grid was acquired in 1987 by the SA Government, and consisted of 6579 line-kilometres of data at 200m line spacing and 70m terrain clearance.
Lineage
This rSA2004t.nc grid is an airborne-derived radiometric thorium equivalent grid for the Kingoonya (Reedy Lagoon), SA, 1987 (87SA02) (74lu) survey. The survey was acquired under the project No. 2004 for the geological survey of SA. The grid has a cell size of 0.0004 degrees (approximately 40m). A total of 6579 line-kilometres of data at a line spacing of 200m were acquired to produce this grid. To constrain long wavelengths in the grid, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey grid (Milligan et al., 2009). This survey grid is essentially levelled to AWAGS. Details of the specifications of individual airborne surveys can be found in the Fourteenth Edition of the Index of Airborne Geophysical Surveys (Percival, 2014). This Index is also available online at http://pid.geoscience.gov.au/dataset/79134. Further up to date information about individual surveys can also be obtained online from the Airborne Surveys Database at http://www.ga.gov.au/oracle/argus/.The original grid was converted from ERMapper (.ers) format to netCDF4_classic format using GDAL1.11.1. The main purpose of this conversion is to enable access to the data by relevant open source tools and software. The netCDF grid was created on 2016-08-29T10:51:42 and has its y-axis indexed Southward-positive.
References
Milligan, P.R., Minty, B.R.S., Richardson, M. & Franklin, R., 2009. The Australia-wide Airborne Geophysical Survey accurate continental magnetic coverage. Preview, No. 138, p. 1-128.
Percival, P.J., 2014. Index of airborne geophysical surveys (Fourteenth Edition).
Issued: 2011
Data time period: 1987-03-29 to 1987-03-31
text: northlimit=-30.024722; southlimit=-30.303122; westlimit=135.827273; eastLimit=136.507273
Subjects
AWAGS |
Australia |
Earth sciences |
NCI |
Published_External |
SA |
airborne digital data |
geophysical survey |
geophysics |
geoscientificInformation |
grid |
radiometrics |
survey 2004 |
thorium |
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Other Information
Digital Object Identifier for dataset 7186b949-6ff6-4635-90c7-cc87dac93d29
doi :
http://dx.doi.org/10.4225/25/58a4014225ce6
Fully qualified pathname of NetCDF file on NCI filesystem for dataset 7186b949-6ff6-4635-90c7-cc87dac93d29. Users must be logged onto the NCI network to access this file system. (md5sum=e7e00188231e05d0f15b1ad41b8f07da) (NetCDF file on NCI filesystem for dataset 7186b949-6ff6-4635-90c7-cc87dac93d29)
local : file:///g/data1/rr2/airborne_geophysics/SA/P2004/radiometrics/thorium/grid/rSA2004t/rSA2004t.nc
Identifiers
- global : 7186b949-6ff6-4635-90c7-cc87dac93d29
- URI : http://pid.geoscience.gov.au/dataset/ga/106842
- DOI : 10.4225/25/58a4014225ce6
