MARKS

Mark Linking

Existing or adopted marks captured during a new e-survey must be linked with the equivalent underlying mark existing in Landonline to ensure each mark is recorded only once and avoid duplicate marks. The process of linking existing marks captured during an e-survey with the underlying mark recorded in Landonline is known as Mark Linking.

Mark Linking may be carried out automatically or manually. During automatic linking each mark is linked to the closest underlying mark found within a specified tolerance of the mark. Six tolerance levels are provided.

If the tolerance level is set too small during Mark Linking the marks in your e-survey may not be linked to the underlying marks in Landonline. If the tolerance level is set too high marks in your e-survey may be linked to the incorrect underlying mark. After automatic linking any remaining marks may be linked manually.

It is recommended that two existing marks are manually linked to align your e-survey with the underlying data then you use automatic linking.

The table below lists the six tolerance levels that may be used during the automatic linking process and possible applications where each may be used.

Tolerance Level	Application
0.03m	Surveys carried out in urban areas where underlying marks have SDC status.
0.10m	Surveys carried out in peri-urban or rural areas where underlying marks have SDC status.
0.30m	Urban areas where marks are of non-SDC status, but where the underlying data is of good quality (ie geodetic).
1.00m	Urban areas where underlying data is of a poor quality or rural areas and marks are non-SDC status but where the underlying data is of good quality (ie geodetic).
3.00m	Rural surveys where the underlying data is of poor quality.
10.00m	Rural surveys where the underlying data is of very poor quality (ie back country surveys).

Marks
Marks, Nodes and Coordinates