Therion (software)
Encyclopedia
Therion is a open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

 cave surveying software package designed for the purpose of drawing cave maps and archiving the data describing the cave.

Description


A complex tool to archive data describing a cave, cave system or karst areas as well as a cave map drawing tool. Compatible with Survex
Survex
Survex is an open source cave surveying software package, licensed under the GPL. It is designed to be portable and can be run on a variety of platforms, including Microsoft Windows, Mac OS X, and Unix...

. Developed by Slovakian cavers Martin Budaj and Stacho Mudrak (but available in English). FREE to download from page of Therion surveying software. The format is human readable plain text (excluding 3D models). The objects of map drawing are abstract, so they can be visualised in different symbol sets or after export to GIS one may add to objects attributes used in a particular GIS project. The interface is available in the following languages: Bulgarian, Czech, German, Greek, English [UK/US], Spanish, French, Italian, Portugese [BR/PT], Russian, Slovak and Albanian so far. The maps, atlases, list of continuations and others could be exported from one project in enumerated languages (if typed), too.

Therion solves the most annoying problem of cave cartography – how to keep a map of large and complicated cave system always up-to-date. Main features include:
  • Complete maps with all the detail. No additional ink stroke is needed.
  • Maps are dynamic, always up-to-date – i.e. they are automatically re-drawn if they are exported after loop closure, blunder fix, scale or symbol set change.

  • 3D models of cave passages are created using 2D maps.
  • 3D surface digital elevation model with particular caves.


One of the big advantages of therion is that a structure of map drawings is fully independent of survey data. It means that you can draw partial maps as you are exploring and surveying the cave. Once you have a more clear idea of the structure of the cave system, you can easily redefine structure of maps to better fit the cave. You can split the cave into layers and selectively display them, or generate an interactive atlas. You can define multiple independent "views" of map structure suitable for different purposes.

There are two main structures of data:
  • Surveys - they follow the history of surveying with all necessary data and they may include any kind of comments to save notes which characteristize the cave. Surveys are organized in namespace so you may use the same station name in several surveys. The station names could be numbers, letters or combination of both.
  • Maps - maps are independent from survey structure so one survey may be divided to several particular maps or one map may include the stations from several surveys. In time of generation you may select one particular map, several maps or all the system to draw the final map. Maps themselfs consist from "scraps" - simply piece of cave passage which doesn't overlap itself. One map may include one or more scraps.


Scraps are morphed (morfing) according to real coordinates of included stations after loop closure. Scraps are joined together automaticaly.
Without Therion many of caves would have no usable map: only a lot of partial maps, sketches and notes which nobody would be able to put together.

Check: http://therion.speleo.sk/wiki/doku.php Therion's wikipage], Projects made with help of Therion, http://therion.speleo.sk/samples.docCase studies and read Therion – Digital Cave Maps – an article presented on the 4th European Speleological Congress.
The import of data from other applications

The export possibilities
  • model - 3D model of the cave and surface
  • map - one page 2D map (and surface image) with widely modifiable styles
  • atlas - modifiable 2D atlas (and surface image) on multiple pages
  • cave-list - summary table of caves
  • survey-list - summary table of surveys
  • continuation-list - list of possible continuations
  • database - SQL database of survey and centreline

The export formats for map
  • pdf (Portable Document Format) (If the map was produced using georeferenced data then it also contains georeferencing information. This can be extracted by XTherion to produce georeferenced raster images.)
  • svg (Scalable Vector Graphics), xhtml, survex, dxf (Autocad), esri53, kml (Keyhole Markup Language - Google Earth) Maps produced in dxf, esri or kml formats may be further processed in appropriate software. These maps __do not__ contain visualized map symbols and xvi (XTherion vector image) format, which displays centreline and LRUD information (and optionally morphed sketches) to serve as a background for digitization. Import from PocketTopo "Therion export file" will create xvi files including PocketTopo sketches.

The 3D model export formats
  • loch (3D native format; default), compass or Visual Topo (plt file), survex
    Survex
    Survex is an open source cave surveying software package, licensed under the GPL. It is designed to be portable and can be run on a variety of platforms, including Microsoft Windows, Mac OS X, and Unix...

    (3d file), dxf, esri
    ESRI
    Esri is a software development and services company providing Geographic Information System software and geodatabase management applications. The headquarters of Esri is in Redlands, California....

    (3d shape files), vrml
    VRML
    VRML is a standard file format for representing 3-dimensional interactive vector graphics, designed particularly with the World Wide Web in mind...

    (Virtual Reality Modeling Language), 3dmf (Toporobot's 3D model), kml
    KML
    KML or kml may refer to:* Kamileroi Airport , Queensland, Australia* Keyhole Markup Language, an XML geospatial data file format...

    (Google Earth)
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK