October 2022

NACIS, the North American Cartographic Information Society, have uploaded recordings of this year’s annual meeting in Minneapolis. The playlist contains over 100 videos covering all sessions from the meeting.

Greg Miller, writing for Wired Magazine, in a portrait of Cynthia Brewer, of Colorbrewer fame:

Brewer’s influence on cartography is far-ranging. Others have imitated her approach, developing a TypeBrewer and a Map Symbol Brewer. She’s seen her color schemes in everything from financial charts to brain imaging studies.

It’s a portrait in one of the most renowned technology publications of a university professor working on a rather niche subject — goes to show how much influence Brewer’s work has on our craft.

The fine folks at Crunchy Data have lined up a great set of talks for a one-day conference celebrating this year’s PostGIS day on 17 November. It’s an online event, with sessions scheduled for over twelve hours; wherever you in the world and whenever you’re awake that day, you can drop in at any time. The event is free and registration is now open.

Workflows, a new workflow builder introduced by Carto, allows people to build geo-data-processing workflows without writing code. It simplifies the creation of nested SQL queries. It provides means to import data from an external service or send the processing result via email.

The full extent of capabilities is pretty sparse at the moment. Workflows is currently in private beta; the public beta will be released in the “coming weeks.”

I previously posted a list of updates to Geojson.io. Chris Whong, one of Geojson.io’s maintainers, pointed out on Twitter that most of the functionality I reported as new existed before the update. I have corrected the post based on Chris’ correction and the updated changelog.

The post was the result of sloppy work on my part. I know how to read a commit history, and I should have done that to verify my assumptions.

Darren Wiens with a short and sweet example of how to enhance web maps using SVG filters. Check out the codepen to see an approach in action.

The beauty of the technique is that it’s independent of any mapping libraries. You can use SVG filters with Leaflet, OpenLayers, or MabLibre.

Geojson.io Quietly Receives an Update

Christopher Beddow reported it first (at least in my timeline); the small-scale GeoJSON editor Geojson.io received an update after development had lied dormant for a while. 

There are no recent releases, the changelog hasn’t been updated in over four years, and the Mapbox blog is quiet on the topic. It’s hard to precisely summarise what has changed. But based on my memory of the feature set before the update, newly added features include the following:

  • Project the data using Mapbox’s recently released globe projection.
  • New base maps, including Outdoors, Light, and Dark styles.
  • Load XYZ tile layers from external sources.
  • Create a set of points, ideal if you want to quickly create an artificial dataset for testing.
  • Enhance existing geometries by automatically adding bounding boxes to each feature.
  • Import data from text and binary formats, including:
    • Encoded polylines
    • Well-know Binary (WKB)
    • Well-known Text (WKT)

Update: Chris Whong pointed out on Twitter that most of the functionality outlined above was already existing prior to last week’s update. Chris has also updated the changelog. I missed a couple of new features, including:

  • The underlying mapping library was upgraded to MapboxGL, which enables the globe projection.
  • Automatic formatting of GeoJSON when pasted.
  • Code-folding, ideal for working with long GeoJSON documents.

A new book by Ryan Lambert teaches Postgres and PostGIS using real-world data from OpenStreetMap. 

This book provides a practical guide to introduce readers to PostGIS, OpenStreetMap data, and spatial querying. Queries used for examples are written against real OpenStreetMap data (included) to help you learn how to navigate and explore complex spatial data. The examples start simple and quickly progress through a variety of clever spatial queries and powerful techniques.

Looking at the sample chapter, Mastering PostGIS and OpenStreetMap is very hands-on and very technical.

You can purchase the book for $99 from the website; it’s available in three formats: HTML, PDF and ePub.

Martijn van Exel wrote a review of Every Door, the OpenStreetMap editor for mobile phones:

We had a lot of fun mapping with Every Door, and I think we were more productive adding and updating POIs than we could have been with any other app! There’s lots of little things that make your life easier. […] I would encourage anyone who likes to get out and survey to try it!! Huge thanks to Ilya for making Every Door available to the community.

I have reported on Every Door before; you should read Martin’s review for an opinion from someone who edits OpenStreetMap much more than I do.

QField, is an open-source app for collecting and managing geographic data in the field that integrates tightly with QGIS, the poster child of open-source desktop GIS. Until recently, the app was only available for Android phones, but since the release 2.4 you can also use it on iPhone devices.

During a recent workshop on the fringe of this year’s SatSummit, participants discussed how to design APIs that simplify ordering satellite data. Matthew Hanson wrote a summary of the workshop, noting the complexity of decision-making that goes into ordering data and tasking a satellite; arguably one reason why we haven’t seen a production-ready ordering API so far:

It turned out the most interesting discussions were centered around tasking as a process, rather than the details of a transactional API with a data provider. Tasking is really about the negotiation, as Phil Varner (Element 84) put it: a user says “This is what I want” and the provider responds with “This is what I can offer”. The questions that arose were less about detail and more about how users should interact with the provider. How do users want to discover what is feasible? How do they evaluate multiple possible options and request one or more of those options?

And consequently, how the ordering APIs could be designed:

There was a general consensus that users start by making a “feasibility request. Included in the request is usually a spatial Area Of Interest (AOI) and a date/time range, Time of Interest (TOI), and possibly some additional parameters constraining the options. What is returned by the provider is a list of possible results that may vary by total area of coverage, time of acquisition, price, resolution, sun angle, or by virtually any collection parameter.

Rather than the provider trying to make a decision of what the user wants from the available options, this choice should be pushed back to the user.

The user then gets to pick their preferred options and places the order for the product best suited for their needs.

Detailed notes of the event are on GitHub, providing some early and still rough outlines of potential API states and parameters, amongst insights on more high-level discussions.

There’s a new Carpentries-style lesson teaching the fundamentals of processing geospatial raster and vector data with Python. It teaches the basics of vector and raster data, how to access raster data via STAC, how to do calculations on raster data, and parallelisation with Dask.

The course is designed for in-person workshops, but you can easily follow the instructions at home.

Steven Feldman, analysing What3Words’ 2021 accounts:

The business is powering ahead despite a small fall in sales to £444,382 (no I have not missed out a couple of zeros), they have managed to increase losses from just under £17m last year to just under £44m this year.

To earn £1, What3Words spent almost £100 in 2021. My understanding of economics and running a business is minimal, but that doesn’t look like a healthy business. But the investors keep the money tap open, so everything is fine.

We all love a bit of retro flair on our maps, don’t we? If you agree, then BellTopo Sans might be what you’re looking for. Designed by Sarah Bell, it’s a sans-serif typeface for map labels, inspired by old USGS maps:

When you see this typeface that I’m referring to on these old beautiful maps, you may think it is nothing special. It’s simple. It might even be very similar to a common font that you already know. Perhaps you’re thinking, “Why didn’t she use that font?” But for me, the beauty of this typeface that I see on old USGS maps exists within its subtle differences.

I like BellTopo Sans because, unlike many modern fonts, it is a little rough around the edges — it has character. Look at that upper-case R and that lower-case g; just look at them.

The words 'Thüringen', 'Thüringer Wald', and 'Grosser Inselsberg (916m) displayed using different variations of the font BellTopo Sans.

BellTopo Sans works best in medium font sizes and with a bit of character spacing.

Polylines are an efficient way to represent line geometries. You provide a geometry, and out comes a scrambled string of letters and numbers that encodes the geometry in just a few characters. Polylines are helpful when you want to efficiently transfer geometry information between services. The Mapbox Static Images API, for example, can overlay complex geometries from Polylines, which wouldn’t be possible otherwise because the request-URL length is limited.

Placemark has released a new Polyline JavaScript library, allowing developers to encode or decode coordinate arrays and GeoJSON objects. It does pretty much the same as existing Polyline utilities from Mapbox or Google. Still, Placemark’s solution is a modernised implementation that includes TypeScript types and a neat autogenerated documentation site; it supports ESM and UMD imports and standardises longitude-latitude order.

FOSSGIS is the major German-speaking community event for geospatial open-source software and OpenStreetMap, a smaller, local, German-speaking FOSS4G. It is held annually and usually attracts several hundred people to share and discuss the latest trends and advancements around software, open data and case studies.

FOSSGIS 2023 logo showing the stylised Fernsehturm and a outline of Berlin's administrative boundary.

FOSS4G 2023 will be held from 15 to 18 March 2023 in Berlin. The call for participation is now open until 7 November 2022. As usual, there will be a mix of general and academic talks, lightning talks, workshops and project demos.

JSON documents can be challenging to read, especially GeoJSON, with complex geometries and many feature properties. JSONCrack visualises JSON documents in a graph, making them easier to parse visually and to understand their structure and content.

GeoJSON features as visualised by JSONCrack. It shows the properties object, and the geometry object further broken down into type and coordinates.
GeoJSON features visualised in a graph using JSONCrack.

JSONCrack works best with small(ish) files. I initially tested with a 17.7MB GeoJSON file that contains about 16,000 records. While it parses and formats the file without issues, it can’t produce the visualisation. Only at about 500 records did JSONCrack render the visual representation.

A print publication containing airline maps? Where do I sign up? Directions of Travel is a magazine about just that published twice a year in newspaper format. It is sold online and in selected shops in London, Zurich, and New York.

Picture of an issue of Direction of Travel, focussing on American Airlines and United Airlines.

Can’t wait to get to London for Christmas to get my hands on one of these.