Kelsey Taylor, writing on the Stamen blog:

Chartographer [is] a visualization tool that breaks down different stylesheet properties by layer and zoom level for easy analysis and debugging. Now instead of panning and zooming around the map to find and identify issues, or scrolling through thousands of lines of JSON looking for mismatched zoom numbers, you can visualize how layers are styled at all zoom levels in a single view.

Chartographer looks like a handy tool if you’re hand-crafting map stylesheets.

Ohsome Adds New Filters Feature for Detailed Analysis of OpenStreetMap's History

Ohsome Dashboard, part of a suite of products for exploring OpenStreetMap’s history built at Heidelberg Institute for Geoinformation Technology (HeiGIT), added a handy new feature last week:

We have a new advanced filter feature available in ohsome dashboard. Now you can globally analyze arbitrary combinations of tags and geometry types over the history of OSM.

The Ohsome Dashboard lets you explore the history of OpenStreetMap by looking at arbitrary combinations of tags, OSM object types, periods of time, and areas of interest. Using a more practical description, you see how the length of all ways tagged with highway=primary has developed over the last five years and compare those numbers between Germany, France, and the UK.

Screenshot of a Ohsome graph depicting the development of length of primary highways on OpenStreetMap in Germany, France, and the UK.
Ohsome showing changes of length of primary highways on OpenStreetMap in Germany, France, and the UK.

Amazingly, these results can be produced on the fly. Sure it takes a minute or two to compute, but we’re dealing with vast amounts of data here. The data-exploration products from HeiGIT and the GIScience group at Heidelberg University have come a long way in the last ten years. OSMatrix, which we first released in 2012, was nice to look at, but it wasn’t nearly as helpful in exploring OpenStreetMap’s vast dataset. All of OSMatrix’s data was precomputed into hexagonal bins, and comparisons were only possible for a tiny area.

Now here’s a very cool project: Allmaps, a browser application made by Bert Spaan and Jules Schoonman, lets you geo-reference images from public sources such as libraries and public archives. You provide the URL of an image and set the reference points via the Allmaps interface. Ideal for laying digitised images of old maps over modern-day data and understanding how the geography has changed.

A digitised map from Antwerp overlayed of modern-day data.
A map from 1860s Antwerp from the Boston Public Library layed over a modern-day digital map. Screenshot from

What is unique about Allmaps are the technical underpinnings of the application; relying heavily on open standards to access images and store annotations:

  • Image resources are accessed via International Image Interoperability Framework’s (IIIF) Image API, which doesn’t just return an image; it allows developers to specify region, size, rotation, and format of the returned image — ideal to crop, resize and rotate an image into place on a map.
  • The map’s control points are stored using a format based on W3C’s Web Annotation Data Model. The custom format uses GeoJSON to represent geographic coordinates of control points while placing the corresponding pixel coordinates inside the properties object.

Allmaps combines existing standards in a novel way, designing for interoperability from the start and enabling sharing of geo-referencing data with other applications.

Some early-internet household names are still going. Amongst them is a familiar face I didn’t think still existed: MapQuest, still used by a surprising amount of people today:

More than 17 million Americans regularly use MapQuest, one of the first digital mapping websites that was long ago overtaken by Google and Apple, according to data from the research firm Comscore.

What reminded me of MapQuest the other day: The Azure-Maps tiles that GitHub now uses to display GeoJSON files. Add a button on each side of the map to navigate towards north, east, south or west, and it will look like a MapQuest map from 2002.

Not surprising at all. The impact of the change is marginal, maps aren’t exactly a core feature of GitHub.

As part of the transition, custom icons and formatting of features in geojson and topojson files will no longer be supported.

Not just icons and formatting, it seems GitHub chose the nuclear option. There are lines and polygons alongside points in this dataset, but only points are visible on the map. Plus, it doesn’t show anything in Safari.

Is it latitude, longitude or longitude, latitude? Everybody has an opinion, no one knows. It doesn’t matter — as long as you know what the application or library you’re working with requires.

FlipCoords flips coordinates in the appropriate order and provides the result copy-paste ready in various formats, such as arrays, tuples, URL parameters or JSON objects. Very handy if you ever need to hard-code coordinates.

Felt Is a New Online Map Editor Designed for Collaborative Map Making

Felt, a new web-based map editor, launched in public beta last week.

Felt isn’t just another web GIS; it’s a tool for collaborative map-making. You can drop pins (even using emojis as markers), plot routes and highlight areas on the map and can annotate all this with text, notes and images. But there aren’t any features typical for professional GIS software, such as editing attribute tables or capturing complex geometries and valid topologies. However, Felt supports importing data from various formats (KML, KMZ, GPX, and GeoJSON) and exporting maps to GeoJSON.

This is a tool for anyone to create maps, whether they have prior knowledge in GIS or not. It’s designed for citizen engagement and participatory mapping; it’s for communities, not professional surveyors. Quite similar to the work around participatory mapping that groups like UCL’s ExCiteS and Mapping for Change do.

I like the simplicity of Felt. It focuses on a well-defined use case and is well executed. Much thought went into Felt’s design; the routing tool is a great example. Wherever you click, it snaps to the closest road and automatically calculates the route between two points, so you don’t have to add nodes to follow bends or turns at every intersection. By holding the Shift key while drawing, you can also draw segments that don’t align with the road network.

The team behind Felt found a gap in the current product landscape and is addressing the need nicely. I’m curious where they will take the $15M Series A funding.

Placemark have released a neat map-data conversation tool that transforms data between pretty much any geo-data file format. Upload files or paste text, convert and then download the converted data in no time.

From the announcement post:

In the course of implementing lots and lots of file formats in Placemark, we’ve ended up with some great, reusable tools. I figured it’d be pretty useful to just let anyone use those things, on a convenient drag & drop (or click, or paste) page. I hope it’s useful. Happy Friday!

This list will go out of date, but right now - you can convert:

  • FlatGeobuf
  • CSV
  • Excel
  • Zipped ESRI Shapefiles
  • GPX
  • TCX
  • Encoded polylines
  • Extract data from GeoTIFFs & JPEGs
  • KML & KMZ

This is a tool you want to bookmark.