REPORT TO XXV SCAR
Note: This project was initially called the Antarctic Spatial Data Infrastructure Project - ANTSDIP. You will find references to ANTSDIP in the text below. At XXV SCAR the name was changed to the Antarctic Geographic Data Integration (AGDI) project.
At XXIV SCAR meeting in Cambridge, August 1996, the Working Group on Geodesy and Geographic Information (WG-GGI) agreed to a new geographic data project, termed ‘geographic data integration’. The initial task was to "develop a SCAR proposal for the collection, integration and publication of fundamental geographic datasets of
drawing on existing SCAR, national and international programs".
In September 1997 Glenn Johnstone from AUSLIG was appointed the Project Manager for the Antarctic Spatial Data Infrastructure Project - ANTSDIP. Thus far, there has been a scoping statement for ANTSDIP produced. There have also been discussions and a visit to each of the project leaders for the four fundamental datasets.
The central component of ANTSDIP is the data management aspect - what standards should be used, what metadata exists, how will the data be disseminated, what quality assurance has been done, what end products will result from ANTSDIP and how will these be managed.
Why have an Antarctic Spatial Data Infrastructure?
The SCAR WG-GGI has identified a growing number of digital datasets from SCAR member countries that are being or could be used in research, GIS analysis and planning. Currently there is no formal standard for these datasets to meet - thus causing difficulties in integrating data from different sources. There is no coordinated approach or program to acquire, or even access fundamental datasets. In some cases there is an unnecessary duplication of data. In terms of examining data, often it is collected for a single project and could have limited or no access available.
The four fundamental datasets WG-GGI identified at Cambridge are considered - by the scientific community - to be the building blocks for further research.
There is a wide range of other scientific disciplines for which improved fundamental datasets for Antarctica would be a major benefit. These include:
When the project was first devised the thinking was that it would have a "hands-on" role in actually converting data into an Antarctic SDI format. The six phases below represent how the project was initially conceived.
This report recognises that original four fundamental datasets are valued by those involved in global applications, while the wider science community would be slightly more limited by just these four. To this end the Project Manager has decided two further fundamental datasets require inclusion in ANTSDIP. These themes are Names and Features. Categories in the Features theme include:
The inclusion of these two extra themes enables a wider variety of the science community to use data that meets an Antarctic Spatial Data Infrastructure standard.
User Needs and Data Management
Table 1 and Table 1.1 outline the characteristics or criteria that represent an ideal dataset for an Antarctic Spatial Data Infrastructure and how the data should be managed. The scoping paper for ANTSDIP had a number of questions about how the fundamental datasets are to be managed. These questions are answered in Table 1. The actual figures in Table 1 are not fixed and discussion on these is welcomed.
A brief description of each of the criteria is given below:
To implement the plan described in Table 1 it was felt that an ANTSDIP Steering Group should be formed. This would help to develop formal links for the project with the science community - represented by GLOCHANT - and data management aspects - through JCADM. The steering group should meet regularly and report the Coordinator of SCAR WG-GGI's Geographic Data Program on progress of the project. An ANTSDIP homepage and contact point via the World Wide Web on the SCAR WG-GGI site is also recommended.
Analysis of existing datasets (Table 2 through to Table 7) for the seven criteria (geodetic datum, data, directory, access, quality, maintenance and standards) reveals that there are no datasets that fully meet the user needs of an Antarctic Spatial Data Infrastructure.
It is useful here to provide slightly more detail on the current status of each of the fundamental datasets. Individual project leaders will be giving up-to-date status reports at the Concepcion meeting. This paper provides a brief summary of each dataset - based on discussions between the ANTSDIP Project Manager and dataset project leaders and personnel.
Bathymetry (GEBCO dataset) - Talks with the International Hydrographic Bureau (IHO) revealed that there is limited digital data held by the IHO and what they do have is quite specific and large scale. The current strategy is that the ANTSDIP will use the digital version of the General Bathymetric Chart of the Oceans (GEBCO) dataset for the bathymetric component of the project along with other data from the IHO where necessary. The GEBCO Digital Atlas (GDA) is maintained by the British Oceanographic Data Centre (BODC) on behalf of the IHO and the Intergovernmental Oceanographic Commission (IOC) of UNESCO. Formal clearance from BODC and the IHO to use the digital data for ANTSDIP is required. Currently there is some work being done by British Antarctic Survey - turning the 1000 metre contour interval into polygons for tinting - primarily this involves joining broken lines. The GDA has been put together as a digital cartographic (or simple vector) product. To make the 1000 metre contour GIS- compatible (ie. topologically structured) has taken many hours of work.
Surface Elevation (RAMP) - The DEM is based on the Antarctic Digital Database (ADD), ERS-1 SAR altimetry data as well as data from USGS, Japan and the University of Minnasota. ERS-1 altimetry data has been used in the ‘flatter’, inland areas of the continent where the ADD data has been a bit sparse. The ADD was used in the more mountainous areas around the peninsula and the Transantarctic Mountains. The post-spacing used across the continent has varied from 200 metres in the mountainous areas to 400 metres in the interior. The expected Z value resolution is approximately 10 metres. Information on where ADD and altimetry data has been used requires further documentation and Dr Jezek anticipates each pixel will have a reference back to source data. It is hoped that this information will be available to SCAR by mid to late 1999.
Bed Ice Elevation (BEDMAP) - It seems likely that BEDMAP will initially produce a model with a nominal grid resolution of 5 kilometres. Finer resolutions may be achievable if modellers have access to the original data to create their own models. Bed Ice elevation data only really available for areas where SPRI, BAS and Australia have collected data, other areas on the map such as the Russian traverse lines are only an indication of the navigational route and as yet no data has been produced. Work has therefore been limited to the data available and is progressing, albeit, at a slow rate. Dr Vaughan would like to see BEDMAP data go out to the 1000m bathymetric contour mark, ie. the continental shelf and past the grounding lines. There has been, very recently, the appointment of a BEDMAP Database Manager to push the project along.
Coastline (Antarctic Glaciology and Coastal Change Project) - At this stage only one map (of the Bakutis Coast), a cartographic product, has been produced with 1 to the east and one to the west almost ready to be digitised. The rest of the data remains in a raw state - as lines on film covering a 1:500 000 scale Landsat scene. This is the work that Charles Swithinbank did 4 - 5 years ago. The first map was produced using MapGen software - a home-grown USGS format. It is not known if the MapGen format will easily convert into ARC/INFO, has this has not been tested. No decision has been make yet on the format of the data. The most likely formats are either ARC/INFO or ArcView. So far there hasn't been a comparison between the first map sheet and the Antarctic Digital Database data to see what differences / similarities there are.
Features (Antarctic Digital Database) - Revision of the 1993 published data continues. Spurious data identified by Byrd Polar Research Centre (being used for RAMP) is being corrected. Also data that was incorrectly positioned and missing features have been corrected. Investigations are underway to make the updated version of ADD available via the Internet. The ANTSDIP Project Manager requires further information about plans for updating the features within the database.
Names (Composite Gazetteer of Antarctica) - The CGA has now been published and presented to the WG-GGI members at XXV SCAR. The CGA is also available on the web - www.pnra.it/SCAR_GAZE. Volume 1 of the SCAR Composite Gazetteer of Antarctica contains an alphabetical list of all the names that have been published in national gazetteers, plus basic information about those names. Volume 2 contains a list of 16415 records (reference numbers), one for every geographic feature recognised and named in Antarctica before 30 November 1997.
There are two current projects examining global topographic data and standards for global topographic data to meet. These are the Global Spatial Data Infrastructure (GSDI) and Global Mapping program (ISCGM). ANTSDIP (and through it SCAR) fits neatly into both of these projects as data for continental Antarctica had not previously been represented. The Antarctic / SCAR representative on the GSDI Executive Committee and the ISCGM is Mr Drew Clarke.
The analysis of existing datasets has revealed that no dataset currently meet the full ANTSDIP requirement. The ANTSDIP Project Manager recommends the following course of action:
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