[auscope-geosciml] Position along a borehole/flightline

Simon.Cox at csiro.au Simon.Cox at csiro.au
Mon Jun 27 22:30:21 EDT 2011

Dear GeoSciMLers

Some of the AuScope deployment team asked me about how to manage positions in boreholes. 
In principle these should be specified by a single coordinate giving the offset from a datum (e.g. the collar) in a 1-D coordinate system coinciding with the borehole axis. 
However, many deployments are using GIS databases which only allow for 2-D coordinates. 

The suggested workaround is to use 2-D coordinates, in a Lateral Offset Linear Coordinate Reference System. The second coordinate, corresponding to the lateral offset from the linear element, can be set to 0.0 so that the position coincides with the 'linear' element (actually a curve of course). 

Linear referencing is part of the v3.3 upgrade to GML currently making its way through the OGC approval process. The work on this aspect was done by Paul Scarponcini of Bentley Systems - who have an interest in infrastructure, roads, communications, cables, etc and positions relative to these, as well as David Burggraf of Galdos - who have been working with the DIGGS community who are interested in boreholes. Examples instances can be found in the GML v3.3 draft which is available on the OGC portal here: 


Pay particular attention to Section 9.5.10 where examples of the CRS definition and direct positions using this are given. 

GML 3.3 is about to go to RFC and we would expect it to be approved by OGC later in the year. 

Hope this is helpful. 

GeoSciMLers - can someone put this in the right place on the Wiki? 
Florence - can you put this on JIRA please. 


Simon Cox | Research Scientist
CSIRO Earth Science and Resource Engineering 
ARRC, PO Box 1130, Bentley WA 6102, Australia 
Tel +61 8 6436 8639 | Mob +61 403 302 672
simon.cox at csiro.au | http://www.csiro.au/people/Simon.Cox

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