Tag: georeferencing

Leventhal’s Urban Atlas Explorer Atlascope Is Expanding, Seeking Sponsors

Published on by Jonathan Crowe
A screenshot of the Leventhal Map Center's Atlascope platform, which presents late 19th- and early 20th-century urban atlases in a web interface overlaid on a modern street map.
Atlascope (screenshot)

Speaking of georeferencing old maps, the Leventhal Map Center at Boston Public Library has a collection of late 19th- and early 20th-century urban atlases. Their Atlascope platform presents 101 of them in a web interface overlaid on a modern street map. The Leventhal is now looking to expand Atlascope’s coverage beyond the Boston area to towns and counties across Massachusetts, and is raising funds to do so (it can apparently take 60 hours to process one atlas). Details on sponsoring an atlas here. See their Instagram post.

GeoTIFFs Explained

Published on by Jonathan Crowe
Neueste General- Post- und Strassen Karte der Oesterreichischen Monarchie : mit politischer Eintheilung der einzelnen Provinzen derselben und Angabe der wichtigsten Bergwerke u. besuchtesten Mineralquellen : nebst einer bildlichen Darstellung des Monarchie-Wapens, so wie sämmtlicher Provinzial-Wapen
Neueste General- Post- und Strassen Karte der Oesterreichischen Monarchie, 1854. Map, hand-coloured, 71 × 104 cm. Library of Congress.

The blog of the Library of Congress’s Geography and Maps Division isn’t the first place you’d expect an explanation of the GeoTIFF format (basically, an image file in TIFF format that includes georeferencing metadata, so that the image can be projected on a map grid). But georeferencing old maps so that they can be placed on a modern map grid is definitely a thing, and Carissa Pastuch’s piece, “The Secret Life of GeoTIFFs,” looks at GeoTIFFs through the lens of an experimental dataset of georeferenced late 19th- and early 20th-century Austro-Hungarian maps.

Georeferencing Familiar Places

Published on by Jonathan Crowe

On the Leventhal Map Center’s website, Ezra Acevedo describes what it’s like to georeference a century-old atlas of your hometown. “Spending many hours poring over maps of such a well known place was really exciting. My knowledge of the town coupled with its resistance to change meant that the historic maps of Ipswich weren’t all that difficult to line up with the modern map. However, I did learn four important lessons while georeferencing my hometown.”