<p>This data package contains three airborne geophysical datasets that have been acquired and processed from the Lower Macquarie River TEMPEST AEM survey flown in 2007, located to the north-west of Dubbo in the Central West region of New South Wales. The datasets are: a new Geoscience Australia layered earth inversion (GA-LEI) of the 2007 Lower Macquarie River TEMPEST Airborne Electromagnetic (AEM) survey; an airborne magnetic survey; and a digital elevation model (DEM). These data include enhancements of previously available datasets using more recent geophysical processing software advances.

<p>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.

<p>The AEM dataset comprises the final Geoscience Australia layered earth inversion (GA-LEI) of the Lower Macquarie River TEMPEST AEM survey data, 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; AEM survey outline and flight line vector GIS data; and borehole comparison logs. The GA-LEI AEM data are derived from the 'Lower Macquarie River TEMPEST AEM Survey, NSW, 2007 Final Data (P1140)', available as Geoscience Australia product number 67211 (GeoCat #67211). The GA-LEI has been demonstrated to generate more accurate conductivity predictions than other algorithms for similar TEMPEST surveys.

<p>The airborne magnetics and DEM data in this data package includes the corresponding data from GeoCat #67211, with additional raster and image formats to facilitate accessibility on a range of geographic information system platforms.

<p>The point located data are stored in ASCII files (.asc) formatted with space-delimited columns with an associated comprehensive header (.hdr) 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 GeoTIFF format with associated world (.tfw) files and (.png) legends. The vector data are stored in ESRI shapefiles (.shp) Technical reports are stored in Portable Document Format (.pdf). The datasets are compressed in ZIP files.

<p>The TEMPEST time domain airborne electromagnetic (AEM) survey was flown by Fugro Airborne Surveys over the Lower Macquarie River catchment in 2007. The survey was commissioned by the Australian Government Department of Agriculture, Fisheries and Forestry through the Bureau of Rural Sciences (BRS), now known as the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) and funded under the National Action Plan for Salinity and Water Quality. Geoscience Australia (GA) provided several geophysical services in relation to the survey including survey planning, technical system selection, data quality control and layer earth inversion of the resultant data. Format conversion of the magnetics and DEM data in this product was performed by ABARES from data provided by GA.