UIS Informatics Commission

T-LiDAR Cave Scanning Working Group

Leader: Prof. Donald A. McFarlane, USA.

Rationale:

T-LiDAR (Terrestrial LiDAR - laser mapping) equipment is becoming widely available, and there are already dozens of published cave studies, especially in disciplines such as archaeology, and in the context of reporting volumes of particularly large underground voids. Nevertheless, T-LiDAR is expensive, both in terms of equipment (~EUR 50K) and in field time. Therefore, the speleological community has a vested interest in reducing unnecessary duplication of work, and ensuring consistent standards for the reporting of data.

Examples:

• Big Bat Cave, Kentucky, USA: http://kentuckykarstconservancy.weebly.com/big-bat-lidar.html
• Hand-held mapper: https://wiki.csiro.au/display/ASL/Zebedee

• Mapping a cave: https://www.newscientist.com/article/mg21628954-700-in-search-of-the-worlds-oldest-cave-etching/

We have therefore established a T-LiDAR working group under the UISIC Working Group on Cave Survey & Mapping. The T-LiDAR working group includes Prof. Manfred Buchroithner (Dresden Institute of Cartography, Germany), Mr. Guy van Rentergem (SC33/Flemish Caving Association, Belgium ), and Professor Donald McFarlane (President, UIS Commission on Archaeology and Palaeontology in Caves), but anyone interested in helping is encouraged to contact the Chairman and join the Group.

Goals:

1. Produce a discussion document, in English, French and German versions, for initial approval by the UISIC Survey & Mapping WG.
2. Widely advertise the discussion document through the usual speleological print and on-line sites, inviting comments and criticisms from the wider community.
3. Submit a final proposal, addressing and/or incorporating this international feedback, to the UISIC Survey & Mapping WG for action and eventual publication as a "White Paper".

Issues:

Specific issues likely to be addressed include:

• Open access to data.
• Formats.
• Resolution (grading).
• Georeferencing.
• Standards for the drawing of plans, profiles and cross-sections.
• Standards for computing and reporting of void volumes (TIN generation?).
• Meta-data reporting.

Progress:

A meeting of the several members of the working group was held in Deinze, Belgium, in July 2015. Provisional agreements were made on file formats, specifically:
Open Standard. Archiving will need three files for each project:

1. Point cloud file in generic format; x.y.z. binary.
2. Mesh in VRML format or STL format. Redundant scans should be removed.
3. Metadata file. To include tie-in to surface GPS location, or classic survey (which should be included in the metadata file).
   Summary data, e.g. number of scans, dates of scanning, team names.
   Angular resolution(s) used for the scans.

Further discussion was conducted on the issue of non-arbitrary definitions of chambers versus passages. This is currently the subject of Doctoral research by Nico Schertler (Cave Research Group of the TU Dresden Institute for Cartography).

There may be a 3D scanning session at the UIS 18th Congress in Sydney, Summer 2017, which would be an appropriate venue to present the work of the group.

Contact:

Prof. Donald A. McFarlane.
President, UIS Commission on Archaeology and Palaeontology in Caves.
Email: DMcFarlane@kecksci.claremont.edu