Bloggage update: When compared to the local Open Street Map, a 1610 map of the Cambridge UK region from the Harvard University Library will show differences in the distribution of settlements, roads and rivers. Towns important 400 years ago are either less so or absent altogether, and Cambridge doesn't rank among them! Two maps and a comparative table and further details are described in this beautifully drawn ancient map.
Bloggage update: I'm a big fan of the British Library (London UK), whose an amazing array of old maps they just finished georeferencing via crowd-sourcing. These maps are now linked to Old Maps Online, and being an amateur medievalist myself, I found a 1610 map of "Cambridgshire : described with the deuision of the hundreds, the townes situation, with the armes of the colleges of that famous vniuersiti and also the armes of all such princes and noblemen as haue heertofore borne the honorable tytles & dignities of the Earldome of Cambridge [sic]" - read on for little map R&R (restoration and reading) around my in-laws' home village.
Bloggage update: As a fitting end to the Medieval Fenlands Mashup, UK Ordnance Survey will update their Parish shape files that had errors in East Anglia. These were found by running Socium's Online Validation on data downloaded for the purposes of mapping economic wealth in the region since Domesday 1067 survey. HC Darby and Julie Bowring data were simply added to the shapefiles by hand, so that a validation procedure seemed prudent. That is when we noted 25 spikes and kickbacks among 1900 poylgons, pretty good by digitizing standards at 1.3%. It was then a matter of alerting Ordnance Survey in one of their OpenData meet-ups, and presto! we looped the Volunteer Geographic Information loop by feeding back suggestions for the agency to correct. This is one of the benefits of the UK Government opening survey data to the public, who can help improve it in a new twist on crowd-sourcing.
Bloggage update: Here is a small selection of mapping tools available on the iPad. Some are from the Appstore, others simply from the web. The upshot is that while there is a variety of apps available for iPads, web maps appear to work just as well. The advent of HTML5 will especially help in rendering vector maps on smartphone limited bandwidth.
Bloggage update: Two year review of a personal project that shows what free map data to hang sketch maps on, and a little tinkering to add historic wealth data, can achieve to illustrate almost 1000 yrs of geo-economics. Three key elements are: a) a geographic unit that stays constant, b) people who indefatigably document and update such important information, and c) ground truthing i.e. knowing & QCíng the data in order to put information in context.
Bloggage update: online spatial data validation (OVS).
Having transposed historic economic geographic data on shape files from the UK Ordnance Survey in my Medieval Fenlands project a couple of years ago, I can now test through socium.co.uk:
1) how good are vector data in East Anglia, as part of coi.guv.uk data feedback?
2) how well did I transpose attributes from Darby's map plates into shape files?
Using sets of rules on shape files, OVS is as simple as 1-2-3: 1) upload, 2) select the rules to test vector data integrity, 3a) view the report for free on line, or 3b) download it for one credit to get another shape file with "data busts" as points with descriptive attributes.
Having been in the geodata business for decades, I cannot see how data validation can be made any easier, while maintaining - indeed increasing - data integrity. This OVS highlights two of the "holy grails" in matters geospatial:
1) GIS depict complex data in a simple yet effective way, by placing them in their local context
2) web services offer two more opportunities:
a) to post geo-processes on-line that are easy to reach
b) to offer a flexible pricing plan that helps one and all