Recent content on Martijn van Exel
OpenStreetMap (OSM) data comes to you unfiltered, raw. OSM, being a crowdsourced map, gives you no guarantees of completeness, accuracy, or generally fitness for use. It’s up to you to design a data pipeline that gets you the geodata you actually need. Entire teams at large companies have broken their collective brains on the multitude of challenges faced when trying to sanitize OSM data.…
I am not the first poor soul to attempt this, nor will I be the last: mapping OpenStreetMap features to a sensible POI classification scheme. First off, the OSM free form tagging folksonomy can be inscrutable, even for experienced OSM data users and contributors alike. One of the most active channels on the OpenStreetMap U.S. Slack is #tagging. The OSM Community Forum will have at least a dozen…
I wrote about What The Quad , a little tool I wrote to quickly get relevant, copyable information about a map tile, in a previous post. I added a few features today: Bounding Box Mode: you can now draw a bounding box and get its coordinates in the standard, comma-separated format. Copy as WKT / GeoJSON: you can now copy the bounding box, in both the quadkey mode and the new bbox mode, as GeoJSON…
I updated the Meet Your Mappers tool to version 1.2. Meet Your Mappers is a website I made a while ago that lets OSM mappers find active peers in their area. I use it myself to find new mappers to invite to OSM Utah meetups. I wrote about Meet Your Mappers in more detail elsewhere on this blog . I also talked about it at The State of the Map U.S. conference in Boston earlier this year. My slides…
Non-geospatial post alert! As much as I love maps, I do like to take a break from them from time to time to scratch a non-geo itch. I like little side projects, because they give me an opportunity to learn something new, and find out how well my engineering skills, such as they are, translate to a domain I am not quite so comfortable with. One side project that has been on my list for a while is a…
If you are interested in custom OSM data quality analysis with actionable results that can be used to engage the OSM mapping community, or guide your own teams to solve specific quality issues you care about for your use case, you can hire me ! One area where OpenStreetMap (OSM) really shines in United States cities compared to other, proprietary maps is the quality of pedestrian infrastructure.…
These are the slides and cleaned up speaker notes for my lightning talk about the Meet Your Mappers tool at State Of The Map U.S. in Boston. Hello everyone! Excited to update you on a new tool I wrote, Meet Your Mappers! I have been running OSM Utah for a while. We have a great group with some of the most active mappers in the Salt Lake City area. I am always looking for more active mappers to…
I have presented on MapRoulette quite a few times over the years. I started the project 13 years ago. MapRoulette has evolved a lot in all those years, but so has OSM, and so has the geospatial domain, and so has technology and society as a whole. Today, I would like to take stock and take the opportunity to look ahead and explore how MapRoulette may adapt to meet existing and new challenges in…
This tutorial demonstrates how to tag turn lanes in OpenStreetMap using JOSM. Starting with a fresh install of Linux Mint and JOSM, I walk through installing the necessary JOSM Paint Style and plugins. Clicking the thumbnail below will take you to Youtube.
I organize a monthly Map Night for OSM enthusiasts in Salt Lake City. There is a small group of regulars, but I actively try to reach out to people who might be interested in joining. One thing I wish I had to do this more effectively is a list of active mappers in my area, but there is no easy way to get such a list. So I built a website that will create that for anyone who is interested in a…
As an active OpenStreetMap (OSM) contributor, I often find myself switching between various OSM-related tools while mapping. Each tool serves a specific purpose - from editing with different editors to analyzing data with specialized visualization tools. I frequently found myself manually copying coordinates from the OSM website URL and pasting them into other tools, which was tedious and…
I spent too much time today on tweaking my Obsidian daily note template. Here is the final thing, read below for a chunk-by-chunk explanation. <% tp.user.motivational() %> > [!todo] > - [[Tasks#In the future]] > - [[Tasks#Anytime]] > ### ⚠️ Overdue > <%* if ([0,6].includes(tp.date.now('d'))) { %> > ```tasks > due before today > not done > ``` > <%* } else { %> > ```tasks > due before today > not…
I have been using Obsidian for note-taking for a while now. I love that its backend is just your file system with regular markdown files. I have only recently started looking into the rich community plugins ecosystem. One particular plugin I’ve particularly enjoyed is the Tasks plugin . I love you you can just use a Markdown checkbox and it will pop up an attributes dialog that lets you add…
I’m looking to improve my front-end / full stack development skills. With help from my online friends, I am coming up with this list of resources. Some loose criteria: Focused on React. Nothing against Vue etc. Just the most common framework, and the one all of my recent employer’s web properties use. Not just videos. Updated or recent. Knowledge gets stale quickly and so do courses…
The OSM map gets denser and denser as more people contribute to the map. In a typical urban or suburban area, you will find trees, houses and other buildings, transit stops, land use et cetera. All this data can make JOSM slow and it can be hard to find the features in the map you want to focus on. That is where filters come in. Some I frequently use are buildings and land use. To add a filter,…
Quadkeys are Bing Maps’s way of subdividing a Web Mercator map of the world into tiles. It is a simple quadtree-like system where each tile at a spcific zoom level has exactly four children: I find myself needing to convert map location on earth in longitude / latitude to a Bing quadkey sometimes, and I found there is no easy web tool to do this, so I wrote one: What the Quad :
On a fresh Linux Mint install, JOSM, the Java OpenStreetMap Editor, is not installed by default. There are a few ways to install JOSM, but the most straightforward ones do not give you the latest version. The only convenient way to ensure you always have the latest JOSM installed is by using Java Web Start, or JWS. JWS is a framework “that allows users to start application software for the…
I’ve been looking into a way to visualize the quality of pedestrian mapping in OSM. Sure, there are already many “How Good Is OSM” maps out there, but I hadn’t really done any GIS work in a little while so it was a good opportunity to stretch that muscle. For the quality metric, I will consider the length of dedicated pedestrian infrastructure relative to the total length…
This post is a follow-up on my series on GoPro Max panoramic imagery capture for Mapillary. Find part 1 here and part 2 here . To capture true 360 degree images with a camera that has just two lenses, compromises are unavoidable. Optics dictate that a lens that captures a 180 degree field of view will have some image sharpness falloff at the edges of the field of view. I hadn’t considered…
Recently, I wrote and published Resto-Bot , a Mastodon bot that toots about a restaurant POI from OpenStreetMap that has not been updated for more that 5 years. It is backed by an OSM database populated by the osm2pgsql tool, and I learned quite a lot about modern usage of this tool along the way. This post contains some of my learnings, and I hope it is useful for folks who would like to have a…
I posted a couple of days ago about my first captures with the GoPro MAX camera I have on loan and uploading to Mapillary. This all went pretty smooth, so I wanted to capture while biking. I bike around town a fair amount and you can cover more ground in the same amount of time compared to walking, so I was eager to try it. Years ago, I captured Mapillary imagery with my regular GoPro HERO 3+…
I have always been excited about the opportunities open street level imagery (SLI) offers to OSM. I helped launch OpenStreetView (now Kartaview) back when I worked at Telenav and was an early contributor to Mapillary as well. Recently, I’ve had the opportunity to work more closely with the great folks at Mapillary. This re-kindled my excitement for SLI & OSM! Good things are rolling out and…
I was doing my usual overthinking on something meaningless earlier so I decided to replace my previous motiv (short for “Letter sized motivational poster with no images”) with this fresh one: I’m not too happy with Google Docs’ complete ignorance about proper kerning, but I decided…not to overthink it. At least they do have Helvetica. Here it is in PDF form if you…
Update: The bookmarklets are updated for the new 2.0 version I’ve been testing the latest alpha version of the RapiD editor . RapiD is a web-based editing environment for OpenStreetMap that incorporates special layers with map features from other sources you can easily copy over to OSM. Examples include Microsoft’s building footprint data, missing roads generated with machine learning,…
We went to Hawai’i for a week over the holiday break. This was our second visit to Hawai’i, by which I mean the island of Hawai’i which is part of the state and archipelago of the same name. The first time we went was in 2014. Since then, a lava flow destroyed an area not very far from where we stayed back then. It was very impressive to see the destruction. I didn’t take…
This is a cross-post from my OpenStreetMap Diary RapiD is an alternative to the OpenStreetMap iD editor that adds the ability to easily add data from approved external sources to OSM. Chances are that you—like me—know RapiD from the MapWithAI initiative, Facebook / Meta’s effort to publish road geometry derived from aerial imagery using machine learning. RapiD started out to support this…
We went to visit my in-laws this weekend. They are huge college sports fans. Basketball and volleyball mainly, but they also go to lots of KU football games. There happened to be one, Duke was visiting. Sold out stadium! I do understand American football just a tiny bit better now! Lawrence is a real college town. But college kids grow up. Some of them stick around or come back. Their needs and…
Twitter has gotten a bit overwhelming. I’m taking a break! Image source: Flickr Commons / National Library of Medicine
I purchased a Lenovo X220 laptop back in 2011, shortly after we first moved to the United States. I used it for years, even when I had access to snappier laptops I got from work. A few years ago, I purchased a Macbook Pro for myself, and the X220 was left gathering dust in a corner.
In the past three hours I have Caught up with my Twitter feed Looked into food waste percentage by country (it’s complicated) Organized a new Meetup for my Remote Workers Lunch Hour Started a technical design document for work Caught up on work chatter Worked through 1/3 of the FastAPI user guide Read up on typing and type hints new to Python 3.6+ (and to me) Looked up a bunch of restaurants…
I love it when more than one of my hobbies come together in a small, contained project. This time it was biking, photography, urban exploration, and programming. I am not extremely good or talented at any of them, but doing and enjoying lots of different things and being okay at them is a good way to roll. You never know when things will intersect in interesting ways! I like to get out on my bike…
I had had suspicions for a while that my Fujifilm X100f has image quality issues when using wide apertures (f/4 and wider). Some reviews mention poor corner performance at large apertures, but I don’t think it’s just the corners. Shooting subjects at close distance, center frame performance seemed poor as well with loss of detail, some ghosting and chromatic aberration. So I thought…
I am reposting selected posts from my old blog below.
Microsoft released a machine-generated dataset of building footprints for the United States some years ago . The footprints are derived from aerial imagery. This works well, most of the time. Where you run into problems is in rural areas, especially where there’s natural features and topography that throws the machine learning off. Then the machine starts to think all kinds of things are…
Back Story: 1994 - 2021 Back in 1994-5, a friend of a friend quit band life, and was selling his 1978 Fender Rhodes Mark 1. I didn’t know a whole lot about the instrument, but I knew I wanted a keyboard instrument to play at home. So I bought it off him for something like 500 guilders, or about €325 in today’s money. When I came to pick it up, I was surprised that it weighed almost…
You are looking at the second of a 2-part blog post exploring how to extract useful information out of OSM data using python and PyOsmium. Check Part 1 first and then come back! See you soon. At the end of Part 1, we had a very basic script that would read an OSM file and filter out the ways that was part of our list of Highways Of Interest, MAIN_HIGHWAY_KEYS = [ 'motorway', 'motorway_link',…
You are looking at the first of a 2-part blog post exploring how to extract useful information out of OSM data using python and PyOsmium. Check Part 2 for the follow-up. Osmium is a very powerful library and command line tool for OSM software. Among its capabilities are data format conversion, filtering by tags, diffing OSM files, and applying changes. Osmium does those things and many other…
Happy new year! On New Year’s Eve, the Dutch traditionally have oliebollen , ‘oil balls’. They taste much better than their name would imply. Compare them to donuts with raisins and apple in them. The Ducth typically get them by the dozen at mobile, seasonal outlets like the one pictured below, at bakeries, or even at the grocery store. However, nothing beats making them at home.…
Update 2022: I can’t find the collection described in this blog post on Flickr Commons any longer. The archive is available on the NIMH website. Flickr Commons was launched in 2008, during the heyday of Flickr, with a mission “to share hidden treasures from the world’s public photography archives.” Some years ago, the Dutch Institute for Military History (NIMH, part of the…
With everyone at home and most in person events canceled, I wanted to find a new way to get together with my local OpenStreetMap mapping friends here in Salt Lake City. We usually hang out 1-2 times a month, at a bar or a coffee shop. I’ve been organizing these events since we moved to SLC in 2011 and I love it, and now I miss it. After trying a Slack ‘hangout’ last month I…
I am taking a Creative Nonfiction writing class. This is my work for one of the assignments. Bellevue. Something pretty to look at. Perhaps Mount Hood in the distance—you can only see it on a clear day—or the lakes both to the west and the east. I stroll along the busy downtown streets on my way to a meeting in a 27th floor conference room. There I will see the Bellevue, but not here at the…
Taken near Tooele, UT. Feb 17, 2020.
I wrote a how-to recently on “Cleaning up” after the OpenStreetMap TIGER import. As a reminder, here’s what TIGER data used to look like when it was imported into OSM in 2008: Fortunately, the OpenStreetMap community has fixed most of the alignment and road classification issues connected to the TIGER import in the past 12 years. (With some help from tools like Battlegrid , which I wrote when at…
I am really proud of how far MapRoulette has come. It is now really easy to create Challenges mappers can work on together to improve OpenStreetMap. Many OSM groups already use MapRoulette to coordinate mapping activities—both volunteer communities as well as corporate mapping teams. Read for example this recent blog post by Monica Brandeis of Critigen , where she explains how Critigen used…
It hasn’t been that long since we moved to this town, this new country. You are from here, know things I do not, move about this uncharted space with its unfamiliar and unwritten rule-set, and I follow you, mimic you, create my map. I speak the language—people comment on my accent, where are you from, Denmark—but I don’t speak the rest of it. When we arrived, the sun screamed at me, louder than I…
I’ve been working on a new version of the TIGER Battlegrid , but haven’t had a lot of time to make progress lately, so in the mean time I’ve been thinking about quick ways to help mappers clean up after TIGER. I have a couple of ideas. One involves MapRoulette that will require a little bit of time to execute. The other one is for JOSM users; just follow the steps below! First, open up the…
When I first started taking photos, the results would be unpredictable and, on top of that, immutable after releasing the shutter. The entire process after that capture moment being a black box: take the film out of the camera, bring it to the camera store, where they develop the film and make prints, exposing them based on some average of the negatives’ exposure. Nevertheless, I was excited to…
In a previous post, I talked about a new MapRoulette challenge to help identify surface parking lots that need more detailed mapping of roads and aisles within the lot. In this post, I want to dive a little deeper into how a Challenge like that is made. Challenges in MapRoulette MapRoulette is the micro-tasking platform for OpenStreetMap. On it, mappers can select any one of millions of Tasks and…
My original attempts at making granola date back 2.5 years. Since then, I have improved and simplified my recipe subtly, so I thought I’d share the new version. The most obvious change is the removal of the egg whites, which make no discernable difference. Preheat oven 275 degrees. Line a baking sheet with parchment paper. Add the following dry ingredients to a large bowl and mix well. 3…