OpenHistoricalMap/Tags/Events

See also: OHM Forum Discussion: Event Tagging - Battlefields, Campaigns, Explorer routes

Description and Discussion of possible Event Tagging schemes. Current work has been focused on tagging battles, and these schemes will need to generalize to cover other usages such as movements of Explorers and Expeditions.

Currently some experimental work is being done on the site of the Antietam Battlefield (part of the Maryland Campaign of 1862)

Some older thoughts on tagging battlefield movements may be found on the American Civil War Project page. This page will be updated with current tagging from Antietam and the tagging discussion will migrate from the American Civil War page to here.

Current Tagging

Namespaces

• ephem:
  • namespace for ephemeral data
• ephem:mil:
  • namespace for ephemeral data of military application
• ephem:expedition
  • namespace for explorers/expedition tracking

Point in Time

Currently ephem:time=* could be start_date=* and end_date=* with the same time if a single point in time.

Temporary Burials & Relocated Cemeteries

• landuse=cemetery
• start_date=*
• end_date=*
• name=*
  • At Antietam, Union Temporary Burial, Confederate Temporary Burial, Horses Temporary Burial
• description=*
  • additional information if available (e.g., which unit was buried there)

Troop Positions

Currently using the ephem: namespace (short for ephemeral.) This could be event or something else. Probably shifting these to ephem:mil: in the near future.

On ways and nodes

• time
• ephem:mil:deployment=*
  • line, column, bivouac, vidette
  • direction of way matters for line and column. for column, direction march. for line, apply right hand rule to get direction of march
  • areas or points good for bivouac and vidette

On relations

Unit information is abstracted into relations. The relation containing the way and/or nodes would have been located at that point at the specified time, facing as described above. The relation contains multiple such ways/nodes, indicating the progress of that unit over time.

• type ephem:mil:unit
• ephem:mil:unit=*
  • company, regiment, brigade etc.
• name=*
  • name of unit, e.g. 12th Massachusetts
• ephem:mil:branch=*
  • e.g. infantry, cavalry, artillery
• ephem:mil:commander=*
  • name of commander if known

Higher level relations containing these represent increasingly larger units in the Order of Battle. This will inevitably run into the OSM API restrictions on relation nesting. This is not a hard limit but needs to be worked around.

TODO: how to handle change of commander during battle; e.g. John Reynolds was killed early in the Battle of Gettysburg and was replaced by Abner Doubleday for the duration of the battle.