Category: Spatial stuff

  • Free geographical data: Installment 1

    National Land Survey of Finland: http://www.maanmittauslaitos.fi/en/opendata Geoscience Australia: https://www.ga.gov.au/products/servlet/controller?event=DEFINE_PRODUCTS Ordnance Survey http://www.ordnancesurvey.co.uk/oswebsite/products/os-opendata.html

  • Free map tiles

    Map Tile Sources Here is a list of free sources for map tiles. I’ll expand this list as I find more free tiles. Notice that some websites require an attribution. I’ll perhaps update this post with the attribution line for each. Stamen “Toner” World-wide, clean B/W theme

  • Simple Rest API for storing “point” observations

    Database stuff First I’ll describe the database that backs the service. PostGIS database backend Here is how to make a simple table in PostgreSQL, that can store geo-tagged “observations”. It uses a hstore type for key-value pairs and a geography point for the GPS dot. It’s very versatile, and could store anything from bird observations […]

  • Danish Government Basic Data program 2012-2016

    The Agency for Digitisation in Denmark has just published their agenda for publication of so called “Basic Data”. The following page is in english: Good Basic Data for Everyone – a Driver for Growth and Efficiency

  • Protected: Starting up a database reading group!

    There is no excerpt because this is a protected post.

  • Geographically weighted regression reading list

    Slides GWR_Presentation.pdf Articles MethodsReviewPaperNCRM-006.pdf mennis_cj06.pdf http://en.wikipedia.org/wiki/Spatial_analysis

  • Examples of querying a OSM PostgreSQL table with the hstore tags column

    I have found some tutorials (1 and 2) for using the hstore column type in PostgreSQL. This blog post is specific to querying OpenStreetMap data using the tags column in relations ways and nodes (the tags column is a hstore).

  • Import OSM data into PostGIS using Osmosis

    This blog post is made as a “note-to-self” so that I can remember the procedure. You are of course welcome to read along. It’s does nothing fancy, simply imports the planet.osm file into PostGIS using Osmosis with the Snapshot Schema. Step by step Assuming Osmosis is installed (if not download osmosis), and a planet.osm file […]

  • Plotting data on maps with matplotlib

    I’m learning about matplotlib, and actually just bought the book Matplotlib for Python Developers. Geographical plots Browsing stackoverflow, the matplotlib homepage, and other resources, I eventually came by this stackoverflow post, which mentions BaseMap. Since the data that I’m plotting is inherently geographical, it makes sense to show the data on a map. There are […]

  • Pyramidal tile cache cheat sheet

    This table lists the number of total tiles for increasing zoom-level in a tile cache. The tile cache is assumed to be pyramidal: . level 1: 1 tile level 2: 5 tiles level 3: 21 tiles level 4: 85 tiles level 5: 341 tiles level 6: 1,365 tiles level 7: 5,461 tiles level 8: 21,845 […]