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  • <div>The A1 poster incorporates 4 images of Australia taken from space by Earth observing satellites. The accompanying text briefly introduces sensors and the bands within the electromagnetic spectrum. The images include examples of both true and false colour and the diverse range of applications of satellite images such as tracking visible changes to the Earth’s surface like crop growth, bushfires, coastal changes and floods. Scientists, land and emergency managers use satellite images to analyse vegetation, surface water or human activities as well as evaluate natural&nbsp;hazards.</div>

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    Gravity data measure small changes in gravity due to changes in the density of rocks beneath the Earth's surface. 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 National Gravity Compilation 2019 - CSCBA 0.5VD image is derived from the 2019 Australian National Gravity Grids A series. These gravity data were acquired under the project No. 202008. The grid has a cell size of 0.00417 degrees (approximately 435m). This gravity anomaly grid is derived from ground observations stored in the Australian National Gravity Database (ANGD) as at September 2019, supplemented by offshore data sourced from v28.1 of the Global Gravity grid developed using data from the Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration (NOAA), and National Geospatial-Intelligence Agency (NGA) at Scripps Institution of Oceanography, University of California San Diego. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD together with Airborne Gravity surveys totaling 345,000 line km and 106,000 line km of Airborne Gravity Gradiometry were used to generate this grid. The ground gravity data used in this grid has been acquired by the Commonwealth, State and Territory Governments, the mining and exploration industry, universities and research organisations from the 1940's to the present day. Station spacing varies from approximately 11 km down to less than 1 km, with major parts of the continent having station spacing between 2.5 and 7 km. Terrain corrections to gravity were calculated using both offshore bathymetry and onshore topography data. The grid shows a half vertical derivative of the complete Bouguer anomalies (A series) over Australia and its continental margins. A half vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the complete spherical cap Bouguer anomaly grid of the 2019 Australian National Gravity Grids A series.

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    Gravity data measure small changes in gravity due to changes in the density of rocks beneath the Earth's surface. 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 National Gravity Compilation 2019 includes airborne CSCBA 1VD image is a first vertical derivative of the complete spherical cap Bouguer anomaly grid for the 2019 Australian National Gravity Grids. These gravity data were acquired under the project No. 202008. The national grid has a cell size of 0.00417 degrees (approximately 435m). This gravity anomaly grid is derived from ground observations stored in the Australian National Gravity Database (ANGD) as at September 2019, supplemented with offshore data sourced from v28.1 of the Global Gravity grid developed using data from the Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration (NOAA), and National Geospatial-Intelligence Agency (NGA) at Scripps Institution of Oceanography, University of California San Diego. Airborne gravity and gravity gradiometry data were also included to provide better resolution to areas where ground gravity data was not of a suitable quality. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD together with Airborne Gravity surveys totaling 345,000 line km and 106,000 line km of Airborne Gravity Gradiometry were used to generate this grid. The grid shows complete Bouguer anomalies over Australia and its continental margins. The ground gravity data used in this grid has been acquired by the Commonwealth, State and Territory Governments, the mining and exploration industry, universities and research organisations from the 1940's to the present day. Station spacing varies from approximately 11 km down to less than 1 km, with major parts of the continent having station spacing between 2.5 and 7 km. Airborne surveys have a line spacing ranging from 0.5 km to 2.5 km. Terrain corrections to gravity were calculated using both offshore bathymetry and onshore topography data. A first vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the complete spherical cap Bouguer anomaly grid of the 2019 Australian National Gravity Grids to produce the grid shown on this image.

  • ACRES acquired Landsat 7 satellite images showing bushfires in northern New South Wales in early October 2000. Fire fighters brought more than 80 bushfires under control, after more than 150,000ha of bushland were burnt. The image on the left was acquired on 2 June 2000. The second image shows the extent of the fires in the region from South West Rocks in the south to Grafton and the Clarence River in the North.

  • Salt lakes, also known as playa lakes, are a common feature of the Australian landscape, and are a strong indicator of our current and past climates. Despite their abundance they have not been extensively studied in Australia, with little research undertaken since the early benchmark work of the 1970s - 1980s (e.g. Bowler, 1971, 1981) which largely focussed on geomorphologic evolutionary patterns and trends. Notwithstanding, salt lakes contain some of the highest levels biological endemism in Australia (DeDecker, 1983) and their unique, and commonly extreme, chemistry offers the potential for distinctive saline mineralisation and potentially economic concentrations of Li, K, B, REEs, Br and U (e.g. Butt et al. 1984; Nissenbaum, 1993; Orris, 2011).

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    Gravity data measure small changes in gravity due to changes in the density of rocks beneath the Earth's surface. 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 National Gravity Compilation 2019 includes airborne tilt grid is derived from the 2019 Australian National Gravity Grids B series. These gravity data were acquired under the project No. 202008. The grid has a cell size of 0.00417 degrees (approximately 435m). This gravity anomaly grid is derived from ground observations stored in the Australian National Gravity Database (ANGD) as at September 2019, supplemented with offshore data sourced from v28.1 of the Global Gravity grid developed using data from the Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration (NOAA), and National Geospatial-Intelligence Agency (NGA) at Scripps Institution of Oceanography, University of California San Diego. Airborne gravity and gravity gradiometry data were also included to provide better resolution to areas where ground gravity data was not of a suitable quality. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD together with Airborne Gravity surveys totalling 345,000 line km and 106,000 line km of Airborne Gravity Gradiometry were used to generate this grid. The ground gravity data used in this grid has been acquired by the Commonwealth, State and Territory Governments, the mining and exploration industry, universities and research organisations from the 1940's to the present day. Station spacing varies from approximately 11 km down to less than 1 km, with major parts of the continent having station spacing between 2.5 and 7 km. Airborne surveys have a line spacing ranging from 0.5 km to 2.5 km. Terrain corrections to gravity were calculated using both offshore bathymetry and onshore topography data. The grid shows the tilt filter of the complete Bouguer anomalies (B series) over Australia and its continental margins.

  • Categories  

    Gravity data measure small changes in gravity due to changes in the density of rocks beneath the Earth's surface. 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 National Gravity Compilation 2019 - CSCBA 0.5VD grid is derived from the 2019 Australian National Gravity Grids A series. These gravity data were acquired under the project No. 202008. The grid has a cell size of 0.00417 degrees (approximately 435m). This gravity anomaly grid is derived from ground observations stored in the Australian National Gravity Database (ANGD) as at September 2019, supplemented by offshore data sourced from v28.1 of the Global Gravity grid developed using data from the Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration (NOAA), and National Geospatial-Intelligence Agency (NGA) at Scripps Institution of Oceanography, University of California San Diego. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD together with Airborne Gravity surveys totaling 345,000 line km and 106,000 line km of Airborne Gravity Gradiometry were used to generate this grid. The ground gravity data used in the national grid has been acquired by the Commonwealth, State and Territory Governments, the mining and exploration industry, universities and research organisations from the 1940's to the present day. Station spacing varies from approximately 11 km down to less than 1 km, with major parts of the continent having station spacing between 2.5 and 7 km. Terrain corrections to gravity were calculated using both offshore bathymetry and onshore topography data. The grid shows half derivative of the complete Bouguer anomalies over Australia and its continental margins. A half vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the complete spherical cap Bouguer anomaly grid of the 2019 Australian National Gravity Grids A series to produce this grid.

  • Categories  

    Gravity data measure small changes in gravity due to changes in the density of rocks beneath the Earth's surface. 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 National Gravity Compilation 2019 tilt grid is derived from the 2019 Australian National Gravity Grids A series. These gravity data were acquired under the project No. 202008. The grid has a cell size of 0.00417 degrees (approximately 435m). This gravity anomaly grid is derived from ground observations stored in the Australian National Gravity Database (ANGD) as at September 2019, supplemented with offshore data sourced from v28.1 of the Global Gravity grid developed using data from the Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration (NOAA), and National Geospatial-Intelligence Agency (NGA) at Scripps Institution of Oceanography, University of California San Diego. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD with marina data were used to generate this grid. The ground gravity data used in this grid has been acquired by the Commonwealth, State and Territory Governments, the mining and exploration industry, universities and research organisations from the 1940's to the present day. Station spacing varies from approximately 11 km down to less than 1 km, with major parts of the continent having station spacing between 2.5 and 7 km. Terrain corrections to gravity were calculated using both offshore bathymetry and onshore topography data. A tilt filter was then applied to the complete spherical cap Bouguer anomaly (A series) to produce this grid covering Australia and its continental margins.

  • Australia has been receiving Earth Observations from Space (EOS) for over 50 years. Meteorological imagery dates from 1960 and Earth observation imagery from 1979. Australia has developed world-class scientific, environmental and emergency management EOS applications. However, in the top fifty economies of the world, Australia is one of only three nations which does not have a space program. The satellites on which Australia depends are supplied by other countries which is a potential problem due to Australia having limited control over data continuity and data access. The National Remote Sensing Technical Reference Group (NRSTRG) was established by Geoscience Australia as an advisory panel in 2004. It represents a cross-section of the remote sensing community and is made up of representatives from government, universities and private companies. Through the NRSTRG these parties provide Geoscience Australia with advice on technical and policy matters related to remote sensing. In February 2009 the NRSTRG met for a day specifically to discuss Australia's reliance on EOS, with a view to informing the development of space policy. This report is the outcome of that meeting. Australia has some 92 programs dependent on EOS data. These programs are concerned with environmental issues, natural resource management, water, agriculture, meteorology, forestry, emergency management, border security, mapping and planning. Approximately half these programs have a high dependency on EOS data. While these programs are quite diverse there is considerable overlap in the technology and data. Of Australia's EOS dependent programs 71 (77%) are valued between $100,000 and $10 million and 82 (89%) of all these programs have a medium or high dependency on EOS data demonstrating Australia's dependency on space based imaging. Earth observation dependencies within currently active Federal and state government programs are calculated to be worth just over $949 million, calculated by weighting the level of dependency on EOS for each program. This includes two programs greater than $100 million in scale and one program greater than a billion dollars in scale. This document is intended as a summary of Australia's current space and Earth observation dependencies, compiled by the NRSTRG, to be presented to the Federal Government's Space Policy Unit, a section of the Department of Innovation, Industry, Science and Research, as an aid to space policy formation.

  • Normalising for atmospheric, land surface bidirectional reflectance distribution function (BRDF) and terrain illumination effects are essential in satellite data processing. It is important both for a single scene when the combination of land cover, sun, view angles and terrain slope angles create anisotropy and for multiple scenes in which the sun angle changes. Geoscience Australia (GA) is establishing a procedure to conduct physically based atmospheric BRDF and terrain illumination correction for moderate spatial resolution satellite imagery (10-100 m) such as Landsat using a coupled atmospheric and BRDF model. In particular, the method is not dependent on the image data, does not need extensive field data, can be applied equally to different environments and used with different sensors in a consistent way. Furthermore, the corrected surface reflectance derived using this method can be used to calibrate and cross-calibrate satellite sensors. More importantly, the normalized reflectance can be used for time series analysis to trace climate change and land cover variation using multiple sensors (including satellite, airborne and ground based). In this paper, we will describe the algorithm being progressed at GA. Preliminary results from the algorithm will be compared with ground based reflectance measurements for selected validation sites. The paper will also discuss how the environmental input data for the model, such as aerosol, water vapour and BRDF parameters are selected and applied.