Industries: State and Federal Government
Inundation Polygons help prepare for Cyclone Yasi
Cyclone Yasi was the biggest and most powerful cyclone to hit the Queensland coast in living memory. However, Emergency Management Queensland had been preparing for such an event for years.
Over the last five years the Department of Community Safety through the Emergency Management Queensland (EMQ) "Protecting Our Coastal Communities" (POCC) project has been acquiring LiDAR data and producing a highly accurate Digital Elevation Model (DEM) along the Queensland coast – covering communities from Coolangatta to the Gulf of Carpentaria. It has been large and logistically challenging to complete. This has involved using a panel of private LIDAR providers, including Terranean.
The DEM acquisition was part of a 2006 state government election commitment to more accurately identify storm tide inundation along the Queensland coast. The DEM data would also have future uses for other hazards such as flood and tsunami modelling. The DEM data acquired covers an area of over 60,000 square kilometres and is a massive dataset several terabytes in size. The size and complexity of this data raised serious issues on how this data would be used for real decision making, particularly in an emergency situation. The answer was to produce a simplified dataset called storm tide inundation zones or inundation polygons that could be quickly analysed by virtually any GIS software.
After a competitive tendering process Terranean was engaged by EMQ to create the inundation polygons. The project was a very challenging undertaking that involved creating highly detailed data over the 60,000 sq km project area.
The first step was to create 0.25m contours. One metre contours are generally regarded as very detailed and complex over large areas. Generating high integrity contours at an interval of ¼ metre over 60,000sq km from sea level to mountains as high as Mount Bartle Frere was an immense GIS processing exercise. However, the next step was even more challenging. Creating Inundation polygons involves making polygons of the areas between each two adjacent contours. Another name for these polygons is “hypsometric polygons” and no GIS package has a complete solution for developing these long thin and highly complex polygons. Terranean needed to develop a systematic approach that involved using a different GIS modelling software at different steps in the process.
Issues that Terranean needed to overcome were:
- the very high number of nodes within each polygon;
- the fact that the polygons were often nested inside each other;
- the extreme size of the datasets;
- the fact that the data needed to be 100% accurate because of the critical nature of what they would be used for.
EMQ also engaged Terranean Mapping to develop a tool which utilised the processed data and other datasets to produce the final storm tide zones in a format that could be supplied to other agencies.
Prior to Severe Tropical Cyclone Yasi, all coastal local governments were supplied with storm tide inundation zones as per the National Storm Tide Mapping Model. This data was supplied in a simple spatial format that enabled councils to incorporate the data into their own GIS applications to aid in disaster management planning.
The various storm tide zones produced were incorporated into internal EMQ mapping systems. Hard copy maps were also produced and used extensively in the planning for TC Yasi by the Queensland Government. This data was also made available to other agencies to enable them to overlay the inundation polygons in their GIS applications to see potential areas at risk.
EMQ has worked hard over the last five years to capture the data and then use Terranean to process the data into a usable form. In the end this practical and usable dataset was available for distribution to other state agencies and local government in time to be used as an essential disaster management tool in preparation for severe Tropical Cyclone Yasi and other emergency events in 2011.
Geoscience Australia Topographic and Aerial Mapping Services
Terranean is one of only four members on the Federal Government Topographic and Aerial Mapping Services Panel which carries out work for Geoscience Australia (GA) and the Department of Defence (DOD). The selection process to become a member of this panel was rigorous and involved a close review of our track record and an on-site review of our quality systems.
The work involves detailed topographic and planimetric data capture through aerial photography and satellite imagery interpretation, the establishment of topology, attributes, and metadata to exacting standards, and the creation of publication quality cartographic maps.
Due to a continued track record of submitting quality work and passing the detailed GA and DOD Quality Assurance Testing processes, Terranean is now one of the main suppliers to this Panel.
Our quality focus has been reflected in the 57% of work that has passed the 1st submission to VAT (Validation and Testing) and the 90% that has passed the 1st or 2nd submission. As a result, Geoscience Australia has indicated that we are considered one of the two panellists that can be relied upon to complete the more complex projects and to produce consistently high quality work on schedule.
Our team of experienced photogrammetrists and cartographers along with the associated software and hardware guarantees that we can accommodate peaks in demand.
Airservices Australia, Visual Terminal Charts
In 2006, Terranean Mapping Technologies produced the topographic base for the current series of Australian Visual Terminal Charts for Airservices Australia. This work involved generalising the Geoscience Australia Topo250k digital topographic maps (Geodata 2) to the required level of detail, emphasising features that are visible from aircraft and applying symbology and text according to the international specifications for this type of aeronautical chart. Other information on towers, structures and high points were obtained from various databases and maps. The VTC series includes 68 separate charts that were provided in publication ready format. This project was completed within six months of commencement and was delivered in MicroStation format.
Australian Greenhouse Office
Vegetation Change Mapping
The Project
In order to meet the Australian Government’s commitment to achieving greenhouse gas emissions targets, the Australian Greenhouse Office (AGO) established the National Carbon Accounting System (NCAS) for measuring CO2 released and sequestered across the Australian continent. The NCAS monitors changes in carbon tied up in woody vegetation; specifically, monitoring clearing and regeneration. This monitoring required accurate baseline data during the past 30 years.
The Solution
The NCAS used Landsat imagery to map and measure changes in woody vegetation cover in two-year time slices, during the period 1970 to 2002. In order to achieve this, it was necessary to accurately co-register, calibrate, and High-mosaic Landsat images for each time slice, across the whole continent. Software to assist the registration and calibrations was developed by the AGO in conjunction with CSIRO. Terranean developed its own in-house software and, in conjunction with the CSIRO software, implemented efficient quality controlled procedures to meet the exacting specifications of the AGO. Terranean processed all time slices for 12 of the 47 tiles that make up the Australian Continental mosaics.
The Result
Terranean was recognised as one of the major Remote Sensing companies in Australia and was awarded over 25% of the high quality work involved in this major Federal Government initiative.
Department of Lands NSW
Key Diagram Geo-referencing
What are Key Diagrams?
Key Diagrams are mapping indices that indicate the geographic location of aerial photography centres at the time of exposure. They contain information such as the date, film numbers, and frame numbers.
The Problem
Historically, Key Diagrams were kept on a different floor, in a cabinet not necessarily in order, and not necessarily in a cabinet. Departmental staff did not know what photography they had or what imagery was available at a given location. Some requests could take hours or even days to process.
The Solution
The Department of Lands needed key diagrams to be converted to electronic format and integrated into one effective index, which could be quickly accessed and reported on.
Terranean Mapping Technologies was commissioned to carry out this work.
As a first step, Terranean geo-referenced the 1974 key diagrams from NSW Department of Lands “standard coverage mapping program”, which indexed photography dating back to aerial surveys from 1948. This is pre AGD66 covering the whole of NSW.
LPI scanned into digital format and then supplied them to Terranean, where each sheet was referenced to GDA94 and supplied back as integrated geo-referenced GDA94 diagrams. Software was developed to automatically determine the projection and extents of each map from the name, which incorporated the mapsheet number and year of publication.
The Result
Departmental staff now can offer far greater levels of customer service, by using their desktops to quickly determine what aerial photos are available anywhere throughout NSW. Large areas of storage space are no longer required to keep old physical Key Diagrams Map Sheets. Also, staff now have the option of deploying the data over the Internet.
United States Census Bureau
Data Accuracy Improvement Project
The Challenge
The United States Census Bureau (USCB) is currently undertaking preparations for the upcoming 2010 US census. USCB workers will use handheld computers, instead of clipboards and pencils, to collect information from respondents. These handheld computers will have a map-based display and will be linked to Global Positioning System (GPS) to provide exact location information.
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An accurate base-mapping data set is required for the census. To achieve this, the USCB has implemented the Data Accuracy Improvement Project, which requires road, river, rail, and other geographic features in their digital data to be updated using supplied County spatial datasets.
The Solution
The USCB Data Accuracy Improvement Project provided an ideal opportunity for Terranean Mapping Technologies to develop an innovative solution to a problem, known as “conflation”, which had not been adequately solved anywhere else in the world. During a significant research and development phase, Terranean worked in conjunction with a business alliance partner in the US to develop a robust procedure for combining unrelated and disparate mapping layers to create very accurate integrated layers suitable for USCB systems.
Both off-the-shelf programs and a substantial amount of in-house software were used and developed to fine-tune the conflation process. In addition to software, detailed procedures and quality assurance methods were continually improved to ensure project success.
The Result
Terranean successfully resolved a major worldwide technical problem by successfully applying the process of conflation. Terranean then used the process to compile updates covering eleven County areas across the states of Kentucky, Michigan, Illinios, and Virginia. In each case, Terranean successfully met the USCB’s strict 99.8% accuracy specifications. The conflation process corrected over 136,000 data elements. USCB staff will use hand-held mapping computers, as pictured above, for collecting the 2010 census information. These systems use mapping data produced directly by Terranean, which was awarded the 2004 Asia Pacific Spatial Excellence Award for Export for this project.