Open Historical Map
Open Historical Map (OHM) (http://www.openhistoricalmap.org) is an effort to use the OSM infrastructure as a foundation for creating the world's most universal, detailed, and out-of-date map. OHM will focus on the mapping elements where OSM excels - shores, political boundaries, buildings, and ways. Future and other efforts may engage in discussing actions, events, people, and movable items.
Note: As opposed to other projects such as OpenSeaMap, OHM makes use of its own database independent of OSM.
An early draft Open Historical Map/FAQ is available.
Contents
OHM projects
Editing OHM
OpenHistoricalMap data can be edited online using both iD and Potlatch. The iD editor is embedded within the OHM website.
You may also edit using JOSM by choosing "Edit with Remote Control" in the dropdown menu next to the "Edit"-button on the website. Ensure that Remote Control is enabled under Preferences in JOSM and that JOSM is running. The api will be connected automatically.
If you want to manually start editing OHM in JOSM, it is necessary to alter the api connection parameter (uncheck the default): use http://www.openhistoricalmap.org/api/ (note http not https as on the OSM site).
How to map
Tagging
start_date=* and end_date=*
Apply a start date and/or end date to the feature. The format is ISO 8601 format YYYY-MM-DD.
If you do not know the actual day, you can just add the year, e.g., start_date=1925.
Examples:
- 1901-01-20
- 1902-12
- 1878
- 1900..1925 (between 1900(-01-01) and 1925(-12-31))
- 1900-06..1901-04-23
- before 1910-01-20 (before a specific date - possibly when a photo was taken)
Tracing from imagery
An example URL for a Tile Server is http://nls-3.tileserver.com/nls/8/128/79.jpg. The URL template from that source would be http://nls-3.tileserver.com/nls/{z}/{x}/{y}.jpg.
JOSM - works with WMS Server, Tile Servers and local images. See JOSM Imagery Guide for more information.
iD Editor - open the layers panel, click "Custom" and paste in a valid Tile URL template.
Further notes
For further in depth tagging of features, you may consider Comparison of life cycle concepts, in particular the date namespace suffix and the lifecycle prefix.
Google Summer of Code proposal
A number of projects that are in the Wikimaps, OSM, OHM, Wikimedia area would benefit from the temporal flexibility in the OSM tool stack. This would allow us to use data across projects, using layers from multiple sources at different time periods. These projects include:
- Design a how-to map.
- Enhance iD and The Rails Port so that a JavaScript time/date slider can be added to control the time period that is of interest.
- Enhance iD and The Rails Port so that meta-data hooks are added to the code that allow for custom deployments of both software. The intent is to support their use as dedicated user interfaces to certain applications (such as medieval walking path editing) while still using a generic data source.
Using the data
There are a variety of ways to use OpenHistoricalMap Data.
For smallish scale it is possible to download data using JOSM. Two alternatives now exist for larger volumes of data or larger areas:
- A weekly OHM planet file (see http://planet.openhistoricalmap.org/).
- A special Overpass instance at http://overpass.openhistoricalmap.org/.
See also these pages for the legal attributions:
- OHM/Copyright - to start documenting copyright-related issues for OHM
- OHM/Contributors
Short-term plans
- OHM/Dev - get The Rails Port, Mapnik, Mod tile, and Nominatim up and running at http://www.openhistoricalmap.org
- OHM/TileServer - Tile serving discussion and docs.
- OHM/Tags - identify OHM tagging conventions
- OHM/Plan - longer-term plans
Keys proposed
Related OSM Projects
- OSM-4D (see German version -translation link on top- as English version needs more translation)
- Historic - OSM Wiki page on Historic sites in general
- Proposed_features/historic_event - Failed proposal for including events in the OSM database
- Historic Objekts - An atlas of historic sites based on OSM
- HistOSM - An atlas of historic sites based on OSM, out of the University of Heidelberg
- HistOSM.org Paper - paper by Michael Auer and Alexander Zipf
Conversations
- Open Historical Map maillist: https://lists.openstreetmap.org/listinfo/historic
- Open Historical Map irc: #ohm on irc.oftc.net
- Group on Facebook: https://www.facebook.com/groups/1513784935591521/
References
- Tech Changes to the OpenStreetMap Stack, Tim Waters, SotM 2015
- City Stripping: building historical road layouts from todays data, Maps Matter blog post, 11 Dec 2014
- Curating a Historical Map, Living With Dragons blog post, 21 July 2014
- Wikimaps Expeditions, Susanna Anas video presentation, SotM 2014
- Historical maps, Jerry Clough video presentation, SotM 2014
- Open Historical Map reusing obsolete information, David Evans, SotM 2013
- Summary of Hangout December 2012
- OSM & Online Time Machines, Jeff Meyer, SotM 2012
- Mapping History on Open Street Map, Frankie Roberto, SotM 2009
