Layered earth inversion and related airborne geophysical datasets derived from the Honeysuckle Creek TEMPEST AEM Survey, Victoria, 2001

This data package contains three airborne geophysical datasets processed from the Honeysuckle Creek Geophysical survey, Victoria, flown in 2001. The datasets are: a new Geoscience Australia layered earth inversion (GA-LEI) of the Honeysuckle Creek TEMPEST Airborne Electromagnetic (AEM) survey; an airborne magnetic, gamma-ray and elevation (MAGSPEC) survey; and an extract of the Australian National Gravity Database (GRAVITY). The additional processing and enhancement of the 2001 geophysical survey data has significantly improved previous conductivity predictions as well as enabling the extraction of geologically significant information to support salinity and natural resource management.

This metadata briefly describes the contents of the data package. The user guide included in the package contains more detailed information about the individual datasets and available technical reports.

The AEM dataset comprises the final Geoscience Australia layered earth inversion (GA-LEI) of the 2001 Honeysuckle Creek TEMPEST AEM survey, produced in 2008. The main data products from the GA-LEI inversion are: point located inversion output data; horizontal layer conductivity grids below ground surface; horizontal conductivity-depth slice grids of various regular depth intervals below ground surface; vertical conductivity-depth sections along each flight line; horizontal conductance distribution grids; a grid and images of conductance distribution; grids and images of interpreted bedrock topography and regolith thickness; and images of the above datasets produced using standard image enhancement techniques. The GA-LEI AEM data are derived from the 'Honeysuckle Creek TEMPEST AEM Survey, Victoria, 2001 Final Located Data (P903)', available as Geoscience Australia product number #65384. The GA-LEI has been demonstrated to generate more accurate conductivity predictions than other algorithms for similar TEMPEST surveys.

The MAGSPEC datasets are: airborne magnetic data comprising grids of total magnetic intensity (TMI), TMI reduced to pole (TMI-RTP), TMI-RTP first and second vertical derivative data and a range of enhanced magnetic images derived from the data; airborne gamma-ray data comprising grids of dose rate, concentration of potassium (K), thorium (Th) and uranium (U) and a range of enhanced gamma-ray images derived from the data; and elevation data comprising grids and images of the digital elevation model (DEM) derived from the MAGSPEC survey.

The GRAVITY dataset includes point located data, polygon location data, grids and enhanced images of data extracted from the Australian National Gravity Database.

The point located data are stored in ASCII files formatted with space-delimited columns with an associated comprehensive header file. The gridded data are stored in ER Mapper and ESRI grid formats as binary floating point raster grid files. The image data are stored in JPG format with associated world files. Polygon and other point location data are stored in ESRI shapefiles. Technical reports describing the data processing techniques are stored in Portable Document Format. 

The survey was commissioned by the Murray-Darling Basin Commission in 2001. Fugro Airborne Surveys Pty Ltd was contracted to acquire and process the AEM survey utilising the TEMPEST time domain airborne electromagnetic system. Kevron Geophysics Pty Ltd was contracted to acquire and process the MAGSPEC survey utilising an industry standard system. The project was administered by the Australian Government Department of Agriculture, Fisheries and Forestry through the Bureau of Rural Sciences), now known as the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES). Geoscience Australia managed and quality controlled the work of Kevron and Fugro. Additional processing and enhancements of the 2001 airborne geophysics data was undertaken by GA in 2007-08, with funding from the National Action Plan for Salinity and Water Quality.

Tags: AEM, Airborne Digital Data, Airborne Electromagnetics, Geophysics, Point Located, Published_External, geophysics
Organization: Geoscience Australia Data