Open Historical Maps

Open Historical Maps: Crowdsourcing, Open Source GIS, and the Research Web

ABCD GIS Group, Harvard Center for Geographic Analysis
Wednesday 15 April 2009 from 12.00-14.00
CGIS North Building, Room S050, 1737 Cambridge Street

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Our presentation will show how open source GIS and curated “crowdsourcing” can create an infinite archive of places for digital historians and ethnographers. While the importance of space and place to their research has long been acknowledged by social scientists, there remains a wide gap between their theoretical concerns and the data-driven empiricism of GIS. For those without technical or database skills, maps and geodata are mostly commonly to illustrate rather than advance an argument. However the web can render the tacit knowledge of geography implicit in most historical and ethographic narratives available to the scholars in entirely new forms. We will showcase our ongoing work with the Maps Division of the New York Public Library on a web-based Map Rectifier and Digitizer, a platform for scholars and entusiasts to georeference scanned historical maps and digitize historical features of cities and the environment.

SHEKHAR KRISHNAN is a researcher and activist pursuing his doctorate in History and Anthropology of Science Technology & Society (STS) at MIT, where his research on the history of technology and the urban environment in colonial Bombay and western India. He has been a project fellow with Zotero at the Center for History and New Media at George Mason University. With Schuyler Erle, he manages geo-spatial web projects for the New York Public Library and the Network in Canadian History of the Environment (NiCHE). 

SCHUYLER ERLE has been a free and open source software developer, project leader, and evangelist for over a decade. He is a co-author of Mapping Hacks and Google Maps Hacks, both published by O’Reilly Media. He currently lives in New York City, where he leads EntropyFree, a technology consultancy focused on geographic information systems (GIS), natural language processing, academic computing and humanitarian aid.


Filed under: main — Tags: , , , — Shekhar @ 13 April 2009 7.17 am

Freemap Workshops

Schuyler and I just submitted our applications to Asia Source II, which will be held in Sukabumi in West Java, from 22-30 January 2007, organised by the International Open Source Network (IOSN). Schuyler and I first met at Asia Source I, organised by the Tactical Technology Collective outside Bangalore in January 2005. It was as close as I have come to a religious conversion. In tribute to the spirit of Asia Source, here is our over-ambitious proposal for organising a Freemap Workshop on open-source geo-spatial tools and locative media for the participants from NGOs and SMEs in Southeast Asia at the next camp in Indonesia. While we won’t know if it’s been accepted for another month or so, this template can be implemented in a town near you. Give us a call.


Filed under: Uncategorized — Tags: , — Shekhar @ 26 November 2006 11.00 pm

Quiet Pleasures of Geo-Rectification

I finally gave the new OpenLayers Map Rectifier a serious crash test today, and a few hours later I was still in the same quiet groove, with rosy visions of what it might make possible for historical geography. The rectifier has enormous potential to give users an easy point-and-click interface for geo-referencing and then warping their own flat maps of places, for use as layers in a geographic database. What this means is that I now am within reach of a tool which will allow me to begin creating layers of the various maps of Bombay and loading them as layers in the Mumbai Free Map, as I can now easily warp any image by making a few markers based on common landmarks between the source map and reference map.

This screenshot shows the 1969 Bombay City Guide Map loaded into the rectifier, tagged with a few common markers between the source image on the left and the new layer on the right, now warped according to the surface of the earth. Chris Schmidt helped squash a small bug to get this rendering to work, and I’m hoping that the team can implement the projection system for Mumbai (WGS Datum 84 and UTM Zone 43N) so we can begin serving layers live to the Mumbai Free Map. In anticipation, I uploaded high-resolution maps of Bombay, Salsette, and parts of Thana and Colaba from 1926, 1930, 1933, and 1969. Go to to one of these maps and zoom in on a neighbourhood you know, and load up the satellite imagery in the reference map, and click away.


Filed under: Uncategorized — Tags: , — Shekhar @ 19 November 2006 2.32 am

Cartographers and Bibliographers in Chicago

Days before leaving Boston to attend the Digital Humanities Colloquium at the University of Chicago, I received the fruits of my brief visit to Chicago two weeks earlier, two DVDs in the mail containing extremely high-resolution scans of the 1919 City Survey of Bombay sheets, 12 in total, which were made for me by Chris Winter and Joost Dupont at the Map Collection at the Regenstein Library. While Schuyler and I struggled to even open these huge TIFF plates on our laptops, I left for Chicago with excitement at the possibility of eventually georeferencing and vectorising these sheets to serve as a new layer in the Mumbai Free Map. That project, begun two years ago with the help of Schuyler when he was a hacker and squatter in the Limehouse Town Hall in London, has seen many iterations, both in terms of the project and my close friendship with Schuyler.

For the past six months, the Free Map Server has been running on OpenLayers, which Schuyler develops from his new perch as chief trouble-maker at MetaCarta Labs in Cambridge. OpenLayers now offers a whole suite of tools for geo-referencing maps and turning them into layers. The latest is the Map Rectifier for matching GPS points to images and automating the creation and projection of geo-data. In future it will have a tool for vectorisation, and an interface for annotating maps with other kinds of information stored in a database. This would make possible a web-based geo-spatial toolkit and mapping service, which researchers and scholars could use for everything from blogging about neighbourhood history to mapping the historical geography of urban land use changes. And we now have the raw data to do this, as well as some new tools.

I had the good fortune, then, to meet Jim Nye, the renowned archivist and bibliographer who runs the Southern Asia Collection and the Digital South Asia Library at the U of C, and get into a lengthy conversation about the recent convergence between the old expert culture of geo-spatial analysis and the new media culture of digital archiving and mapping. While the conference was addressed more to humanities scholars and computer scientists, I am more interested in seeing collaboratons between social scientists and web developers. Jim is one of those rare people who understands both the aspects of digital archiving when it comes to working with materials from India and South Asia — both the tools and the content — and he was recently honoured for his contributions at a roundtable in Madison. When I first met him in Chicago four years ago, I was helping to start PUKAR (which was initially funded by the U of C) and he had scanned for us the Bombay City Guide Maps of 1933 and 1969, which we were able to use for teaching and research in Mumbai at CRIT and KRVIA. Here is the 1933 Guide Map in the OpenLayers Map Rectifier.

Apart from maps, over the past two years Nikhil and I have accumulated a huge store of primary documents including the Bombay Development Committee Report of 1913-1914, all of the annual reports of Bombay Improvement Trust (BIT) from 1899 to 1920, and Samuel Sheppard’s Bombay Place Names and Street Names from 1917 (a classic for local history buffs). All these documents, which I sourced and scanned myself, are stored as PDFs, which must be put to OCR for extracting the text and then making it searchable by place. Gutenkarte demonstrates how this can be done using OpenLayers. I am hoping I can bring Schuyler and Jim into conversation about both helping me with this project to create a historical-geographic database of Bombay. Other interesting collections of digital maps at Regenstein include Chicago in the 1890s and the Imperial Gazeteer of India.


Filed under: Uncategorized — Tags: , — Shekhar @ 17 November 2006 12.56 pm

Map Makers

A couple of weeks ago I had the good fortune to finally met Svati’s occassional house-mate, Anandaroop Roy, who makes his living as a cartographer and information designer living between Poughkeepsie and Brooklyn. Roop is a map-maker whose clients include the Metropolitan Museum of Art, the Asia Society and Yale University and who works mostly with public spatial databases and desktop design tools to produce offline and online maps.

Today Roop and I went downtown to the Center for Architecture for a day-long conference on Visualising the City, a day-long conference of architects and urban designers, civic activists and media practitioners discussing and presenting visual and imaging tools for public participation in spatial planning. While much of this was a familiar utopian rhetoric about empowerment of communities and reclaiming of public spaces, along with many whizzy Flash demos of software under development, there were a number of interesting groups and projects presented.


Filed under: main — Tags: , — Shekhar @ 28 October 2006 7.11 pm