82 posts tagged “geospatial”
2010
Geospatial Indexing in MongoDB (via) New in version 1.3.3. Handles “order by distance from” queries using a geohash approach under the hood, automatically searching nearby grid squares until the correct number of results have been gathered. Bounding box search is planned for a future release.
On walking into a disaster zone. Schuyler Erle: “The World Bank was looking for technical GIS professionals, ideally French-speaking, to go and advise the government [...] I can sort of speak French. Sure, why not?”
The making of the NYT’s Netflix graphic. A database dump from Netflix, some clever hackery in ArcView GIS, hpricot to scrape Metacritic and a lot of careful thought about the UI for navigating the data.
2009
GeoPlanet data available again (via) Good news: the Yahoo! GeoPlanet data dump is available again. An issue with one of their data providers meant they had to remove that supplier’s data from the dump, but it’s now been separated and the dataset is live gain. By the end of 2010 they intend to derive all of the data from completely open sources.
A set of geodata, or a map, is libre only if somebody can give you a cake with that map on top, as a present.
GeoDjango and the UK postcode database. Excellent introduction to GeoDjango using the recently leaked UK postcode database. Obviously, you should only follow the steps in this tutorial using the officially licensed database, available for a mere £1,700.
openstreetmap genuine advantage. The OpenStreetMap data model (points, ways and relations, all allowing arbitrary key/value tags) is a real thing of beauty—simple to understand but almost infinitely extensible. Mike Migurski’s latest project adds PGP signing to OpenStreetMap, allowing organisations (such as local government) to add a signature to a way (a sequence of points) and a subset of its tags, then write that signature in to a new tag on the object.
OpenStreetMap: QuadTiles. Fascinating explanation of a proposal for replacing lat, lon pairs in the OpenStreetMap database with a QuadTile-based addressing system.
EveryBlock source code released. EveryBlock’s Knight Foundation grant required them to release the source code after two years, under the GPL. Lots of neat Django / PostgreSQL / GIS tricks to be found within.
JS-Placemaker—geolocate texts in JavaScript. Chris Heilmann exposed Placemaker to JavaScript (JSONP) using a YQL execute table. Try his examples—I’m impressed that “My name is Jack London, I live in Ontario” returns just Ontario, demonstrating that Placemaker’s NLP is pretty well tuned.
Flickr Shapefiles Public Dataset 1.0. Another awesome Geo dataset from the Yahoo! stable—this time it’s Flickr releasing shapefiles (geometrical shapes) for hundreds of thousands of places around the world, under the CC0 license which makes them essentially public domain. The shapes themselves have been crowdsourced from geocoded photos uploaded to Flickr, where users can “correct” the textual location assigned to each photo. Combine this with the GeoPlanet WOE data and you get a huge, free dataset describing the human geography of the world.
Yahoo! Placemaker. Really exciting new API from Yahoo!—Placemaker accepts a block of text (or a URL to HTML or RSS) and extracts and returns geographical locations mentioned in the text. I just ran my djng blog entry through it and it pulled out “Prague” as the only location mentioned. This should be really useful for adding geodata to existing textual content.
Yahoo! Geo: Announcing GeoPlanet Data. The Yahoo! WhereOnEarth geographic data set is fantastic, but I’ve always felt slightly uncomfortable about building applications against it in case the API went away. That’s not an issue any more—the entire dataset is now available to download and use under a Creative Commons Attribution license. It’s not entirely clear what the attribution requirements are—do you have to put “data from GeoPlanet” on every page or can you get away with just tucking the attribution away in an “about this site” page? UPDATE: The data doesn’t include latitude/longitude or bounding boxes, which severely reduces its utility.
Google Maps Data API (via) I’m disappointed by this one—it’s really just a CRUD store for the KML files used in Google MyMaps. It would be a lot more useful if it let you perform geospatial calculations against your stored map data using some kind of query API—a cloud service alternative to tools like PostGIS.
2008
Represent. Andrei Scheinkman and Derek Willis describe how they built the NYTimes Represent feature using GeoDjango and PostGIS.
FOWA London—Beyond GoogleMaps. Andrew Turner’s talk at FOWA was the most information dense presentation I’ve ever seen, and discussed a huge number of cool geo projects that I’d never previously heard of. Andrew links to the full slides and video, well worth a watch.
OS OpenSpace from Ordnance Survey (via) Ordinance Survey now provide a free JavaScript mapping API for “non-commercial purposes” by “private individuals”. The maps look incredibly detailed, although I can’t find any live API demos on the site (the documentation is illustrated with screenshots).
The overdue Places post II—Prototyping Iconicness. How Flickr Places works.
flickr.places.findByLatLon. New API method for Flickr Places. If only Flickr could return a bounding box for each place...
GeoNames: missing countries. United Arab Emirates and a few other countries are missing from the GeoNames XML set I used to seed Django People. I’ve added UAE by hand; I’ll add the others as soon as I have time.
Flickr Place IDs.
flickr.places.find, flickr.places.resolvePlaceURL and flickr.places.resolvePlaceID combine to provide a really useful, lightweight not-quite-a-geocoder API. It's a shame you can't search for places by providing a latitude/longitude point yet.
2005
A GIS newsletter describes the server-side tech behind Google Maps (via) Apparently it’s using Telcontar’s Drill Down Server, with extensive customisations.