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  • This service represents the National Digital Elevation Model (DEM) 1 Second Percentage Slope product, derived from the National DEM SRTM 1 Second. Slope measures the inclination of the land surface from the horizontal. Percent slope represents this inclination as the ratio of change in height to distance.

  • Light detection and ranging (LiDAR) systems measure surface properties at high resolution, including ground surface elevation, and vegetation height and density. As well as having routine application in studies of surface hydrology, vegetation, ecology, infrastructure and hazard assessments, LiDAR is important in groundwater studies as it can help characterise and inform hydrogeological architecture, recharge and discharge processes, surface water–groundwater connectivity, and groundwater-dependent ecosystems. LiDAR-based high-resolution elevation data support surface and subsurface mapping, borehole data analysis, and the processing, calibration and interpretation of geophysics and remote sensing. Here, we describe several applications of airborne LiDAR to understanding groundwater systems in two case study areas in northern Australia: the East Kimberley area in the Northern Territory and Western Australia, and the Upper Burdekin area in Queensland. The East Kimberley LiDAR data were critical to mapping geomorphology and near-surface hydrostratigraphy, which informed our understanding of recharge processes. The Upper Burdekin LiDAR data enabled the mapping of key surface features such as lava flows and rootless cones, which can act as recharge pathways. <b>Citation:</b> Halas, L., Kilgour, P., Gow, L. and Haiblen, A., 2020. Application of high-resolution LiDAR data for hydrogeological investigations. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

  • Arcview GIS containing a regolith-landfrom map with associated site database. Most sites have a field photograph hot linked into the GIS. Complementary datasets include, digital elevation model and enhanced Landsat TM imagery.

  • Airborne Geophysical Data Acquired as part of the Gawler Mineral Promotion Project. Includes point located, gridded and image data. TEMPEST electromagnetics, magnetics and elevation data.

  • The Geological Survey of South Australia (GSSA) designed the Gawler Craton Airborne Survey (GCAS) to provide high resolution magnetic, gamma-ray and elevation data covering the northern portion of the Gawler Craton. In total, 1.66 million line km were planned over an area of 295,000 km2 , covering approximately 30% of the state of South Australia. The survey design of 200 m spaced lines at a ground clearance of 60 m can be compared with the design of existing regional surveys which generally employed 400 m line spacing and a ground clearance of 80 m. The new survey design results in ~2 x the data coverage and ~25% closer to the ground when compared to previous standards for regional surveys in South Australia. Due to the enormous scale of the survey, the data were acquired using four contractors who employed ten systems to fly the sixteen blocks. To standardise the data from the multitude of systems, Geoscience Australia (GA) employed a comprehensive set of technical specifications. As part of these specifications the contractors were required to fly each of the ten systems over a series of test lines termed the “Whyalla Test Lines” (Whyalla). The final GCAS data provide truly impressive high resolution regional scale products. These will allow more detailed geological interpretation of the prospective Gawler Craton. Survey blocks available for download include: Tallaringa North, block 1A Tallaringa South, block 1B Coober Pedy West, block 8A Billa Kalina, block 8B Childara, block 9A Lake Eyre, block 10 The following grids are available in this download: • Laser-derived digital elevation model grids (m). Height relative to the Australian Height Datum. • Radar-derived digital elevation model grids (m). Height relative to the Australian Height Datum. • Total magnetic intensity grid (nT). • Total magnetic intensity grid with variable reduction to the pole applied (nT). • Total magnetic intensity grid with variable reduction to the pole and first vertical derivative applied (nT/m). • Dose rate concentration grid (nGy/hr). • Potassium concentration grid (%). • Thorium concentration grid (ppm). • Uranium concentration grid (ppm). • NASVD processed dose rate concentration grid (nGy/hr). • NASVD processed potassium concentration grid (%). • NASVD processed thorium concentration grid (ppm). • NASVD processed uranium concentration grid (ppm). The following point located data are available in this download: • Elevation. Height relative to the Australian Height Datum. Datum: GDA94 • Total Magnetic Intensity. Datum: GDA94 • Radiometrics. Datum: GDA94

  • <p>The Northern Territory Geological Survey (NTGS) designed the Mount Peake-Crawford survey to provide high resolution magnetic, radiometric and elevation data in the area. It is anticipated that the data from the survey would help attract explorers into ‘greenfield’ terranes and contribute to the discovery of the next generation of major mineral and energy deposits in the Northern Territory. A total of 120,000 line km of regional data (200m line spacing) and additional infill data (100m line spacing), flown at 60m flight height were acquired during the survey between July and October 2019. The survey was managed by Geoscience Australia. <p>Various grids were produced from the Mount Peake-Crawford Airborne Magnetic and Radiometric Survey dataset and simultaneously merged into a single grid file. The final grid retains all of the information from the input data and is levelled to the national map compilations produced by Geoscience Australia. The merged grids have a cell size of 20m. <p>The following merged grids are available in this download: <p>• Laser-derived digital elevation model grids (m). Height relative to the Australian Height Datum. <p>• Radar-derived digital elevation model grids (m). Height relative to the Australian Height Datum. <p>• Total magnetic intensity grid (nT). <p>• Total magnetic intensity grid with variable reduction to the pole applied (nT). <p>• Total magnetic intensity grid with variable reduction to the pole and first vertical derivative applied (nT/m). <p>• NASVD-filtered potassium concentration grid (%). <p>• NASVD-filtered thorium concentration grid (ppm). <p>• NASVD-filtered uranium concentration grid (ppm).

  • Airborne Geophysical Data Acquired as part of the Gawler Mineral Promotion Project. Includes point located, gridded and image data. TEMPEST electromagnetics, magnetics and elevation data.

  • National Elevation Data Audit is a report outlining all elevation data available across all Australian jurisdictions which was identified by the Intergovernment Committee on Surveying and Mapping's (ICSM) Permanent Committee on Topographic Information (PCTI).

  • Cocos (Keeling) Island is located approximately 3,685km almost due west of Darwin. It is a mid-ocean atoll with a coral reef, and a very shallow (1 - 20 m) shelf surrounds the island. Bathymetry data are required in this area to help identify major seabed processes and habitats. The data are also required to enable modelling of tsunami as they interact with the shelf around the island and the coast. This report describes the methodology employed in creating detailed bathymetry data grids of the Cocos (Keeling) Island region. It covers data collection, quality control and gridding. Descriptions are provided of each dataset employed, the methods used to integrate the different datasets and the attributes of the new bathymetry models. Four new bathymetry grids are presented, including grids that integrate bathymetry with the island's topography.<p><p>This dataset is not to be used for navigational purposes.

  • A digital elevation model (DEM) is a digital representation of the height of the terrain usually interpolated onto a regularly spaced grid. Traditionally, DEMs have been estimated from ground surveys, digitised topographic maps, satellite (SPOT) images and aerial photography. Since the advent of the Global Positioning System (GPS) for aircraft navigation, DEMs can be derived from positional and aircraft radar altimeter data recorded on airborne geophysical surveys. A DEM is useful in any situation where knowledge of the height, slope and aspect of the ground is important. DEMs are widely used in the following landscape studies - botanical, geochemical, environmental, forest, soil, geological, climatological, geophysical, glaciological and natural hazard (eg landslide). Florinsky (1988) gives a comprehensive list of applications for DEMs. These include: - stream flow modelling - landscape analysis - land use and soil mapping - geological/geophysical mapping - road design and other engineering projects Although DEMs have been derived from airborne geophysical survey data for several years, there is little information available on the precision and accuracy of these models. The purpose of this paper is to review the procedure for generating an airborne geophysical survey DEM and to investigate the sources and amplitudes of errors in these models.