| the Christmas Island GIS online
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| Dataset | ||
| Title | Abbot's Booby Bird Data | |
| Custodian | Parks Australia North Christmas Island (PANCI) | |
| Jurisdiction | Christmas Island (Australia) | |
| Description | ||
| Abstract | Abbott's Booby Bird sites on Christmas Island are displayed as point data in the GIS. There are 6272 points. The source of this data was a dBase file from the ANCA PC on Christmas Island (file 'history.dbf' dated 11/11/1992). The shapefile's table contains all fields and data (essentially unmodified) of the original dBase file. The spatial coordinates of the original file were based on a line and peg grid, probably using the bulldozed lines of an old mining grid. Transformation was based on AutocadŽ Release 7 maps also existent on the PC. Data was collected between 1983 and 1992. Additional Abbott's Booby Nest locations were recorded in 2002, they are not included in this data. A seperate dataset 'abbotts_nest_sites_2002.shp' contains the locations and can be found at C:\CIGIS\environment. Metadata is yet to be developed for the 2002 dataset | |
| Search Word(s) | FAUNA Native FAUNA Birds HERITAGE Natural HUMAN ENVIRONMENT Planning |
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| Geographic Extent Name(s) | Christmas Island Edition 1 2010 1:30000 - Geoscience Australia GEOCAT 70145 | |
| Data Currency | ||
| Beginning Date | 01JUL1983 | |
| Ending Date | 11NOV1992 | |
| Dataset Status | ||
| Progress | Complete | |
| Maintenance and Update Frequency | As Required | |
| Access | ||
| Stored Data Format | DIGITAL - ArcView3.1 point data shapefile.
6272 records. DIGITAL - dBase file (history.dbf) based on the Line Peg Grid. |
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| Available Format Type | DIGITAL - ArcView3.1 point data shapefile. | |
| Access Constraint | Restricted, see contact details below. | |
| Data Quality | ||
| Lineage | The original data was retrieved from a hard drive on the ANCA PC in the Abbott's Booby Bird Office on Christmas Island. Almost all raw data was in a local line and peg grid based on one of the island's mine grids, and was not referenced to a known projection. However, the disk did contain a number of maps created in AutocadŽ Release 7. Some of these had been rotated into a Universal Transverse Mercator (UTM, Zone 48) map projection (though in different units). Using these it was possible to derive a shift to Christmas Island Grid 1985 (CIG85). In addition to the AutocadŽ maps, a dBaseŽ file (history.dbf) was retrieved from the PC. This contains abundant data for each Abbott's Booby Bird site. Contact ANCA for an explanation of these attributes. Spatial reference in this database was line and peg coordinates (as described above) and, thus, could be projected to Christmas Island Grid using the shift derived using the AutocadŽ maps. In September 2003 this dataset was converted to the MGA(GDA94) projection using an x y shift (550015 = x, 8780001 = y) on the CIG85 projection. | |
| Positional Accuracy | Since the data points projected to Christmas Island Grid 1985 plot similarly to those in the map abbsite.dwg, used in the initial CIG85 transformation, it is likely the errors are similar. The lines in this map do not appear to be accurately surveyed. The error in the data appears to be in the vicinity of 100 metres. As clearing boundaries and coast (though highly simplified) of the same map plot in far better position (after CIG85 transformation) in relation to the orthophotographs and other GIS themes, the majority of inaccuracy in this theme is probably inherited from the original map (abbsite.dwg). That is, it appears that the clearings and coast of abbsite.dwg are reasonably accurate though very imprecise (intended to be viewed at much greater scale), while the line and peg grid appears less accurate. Thus the grid on the GIS is mainly illustrative at this time. It is also notable that, since Abbott's Booby Bird sites from the more recent history.dbf plot beyond this grid, the grid has probably been extended. It may well be that a more accurate version exists. GA could undertake a correction to this data if common points with the orthophotography can be identified by ANCA. | |
| Attribute Accuracy | Not documented. | |
| Logical Consistency | All items in the dataset are points that describe the sighted locations of the Abbots' Booby bird breeding areas of Christmas Island. Many fields within the dataset are unique to the data collection process and exact uses and description of these fields can be obtained from ANCA. | |
| Completeness | As this data was originally collected for a study of the breeding habits of the Abbot's Booby bird, most of the data has been collected starting in July 1983, there is no clear end date that describes the end of the study period (and the end of data collection). AGSO undertook considerable work to translate these database points into a form suitable form for GIS use. GA also recognises that there is still more work that can be done to yield an up to date and error free data set. | |
| Contact Information | ||
| Contact Organisation | Parks Australia North | |
| Contact Position | - | |
| Mail Address | PO Box 837 | |
| Locality | Christmas Island | |
| State | - | |
| Country | Australia | |
| Postcode | 6798 | |
| Telephone | (08) 9164 8055 | |
| Facsimile | (08) 9164 8755 | |
| Electronic Mail Address | David.Slip@ea.gov.au | |
| Metadata Date | 9-12-2003 | |
| Additional Metadata | ||
| Projection | CIG85 | |
| Printed | June 2012 | |