Project Aims

AWSANZ Conferences

Locational data standard

Sources

Contacts
 

Regional Contributions

South Australia

Tasmania

Locational Data Standard

1. For places where the locations are known exactly.

This includes places identified by archaeological survey or other physical evidence.

Data to be supplied as full Australian Map Grid references, i.e.

Zone 2 digit
Easting 6 digit
Northing 7 digit

Location is to describe a datum point within or near the site. The datum is either:

an identified and distinctive site feature, e.g. existing trig station, corner of a building
new datum [form and placement of datums requires a separate standard].

Accuracy aimed for in providing AMG coordinates for the datum is less than 1 metre.

The reference needs to be backed up with a data field describing the source of the grid reference:

GPS - rectified by reference back to a static station
GPS - not rectified
topographic map
survey from a cadastral datum point of known location.

2. For places without exact location.

Examples include recorded localities where there is no remaining physical evidence, and places which may no longer bear the same name.

a. If a place is within a bay, channel or headland specify the full AMG coordinates (as above) of a central point of the feature, e.g. the mid point of a beach, high point of a headland.

Then specify an Accuracy factor within which the site is likely to fall, using a Log scale:

Accuracy Log derivation Interpretation

1 10(1) Presumed location accurate within 10 metres 
2 10(2) Presumed location accurate within 100 metres
3 10(3) Presumed location accurate within 1000 metres
4 10(4) Presumed location accurate within 10 000 metres

If the Accuracy factor is greater than 4, i.e. if the presumed location cannot be securely located within 10 km, then location is to be specified as the relevant sector map.

Sector maps are 1:250 000 National Mapping Authority system of maps for the Australian coast. The full numerical designation and name of the map is to be given. More than one sheet can be nominated if location is very vague or the feature crosses maps.

Other issues

UTM coordinates will eventually replace AMG coordinates. UTM is not to be used until it becomes the Australian standard.

Latitude and longitude readings may be available for some points, e.g. shipwrecks. These should be paired with AMG coordinates (either converted or independently derived).

Compiled by Denis Gojak, Leah McKenzie and Mike Nash at the AWSA Conference, Melbourne in July 1997.