vmx

2023-07-22 21:50

Finally, after missing one virtual and one in person global FOSS4G I had again the chance to attend a global in-person FOSS4G conference. Thanks Protocol Labs for sending me. This year it was in Prizren, Kosovo. I’m a bit late with that post, but that’s due to doing some hiking in Albania right after the conference.

The organization and venue

Wow. It’s been my favourite venue of all FOSS4Gs I’ve been to so far. The exhibition hall was a great place to hang out, combined with the excellent idea of a 24h bar. I’m not sure if it was used at all times, but definitely for more than 20h a day. Outside, there was plenty of space and tables to hang out, and very close by another set of tables that formed the “work area”. Which was another great place to hang out, with enough power sockets and shade for the hot days.

The main stage was an open air stage with enough seating for everyone. It was converted for the gala dinner to a stage with an excellent live band and the usual big round tables.

For me, the best part was that even the accommodation was on-site. The barracks of the former military basis, which now serve as student dorms, were our home for a week. Pretty spartan, but at a conference I don’t really spend much time in my room, I mostly need just some place to sleep.

Having everything, the talks, exhibition, social events and accommodations on-site makes it easy to maximize the time for socializing, which for me is the number one reason to attend a conference.

Everything was well organized, and it was great to see so many volunteers around.

The talks

I haven’t really selected the talks I went to. I rather joined others where they were going, or listened to recommendations. Often, I just stayed in the rest of the slot to see what else is there. My favourite talks were:

• Smart Maps for the UN and All - keeping web maps open: For me, it was the first time I saw someone speaking at a FOSS4G about using IPFS that wasn’t me. It’s great to see that it gains traction for the offline use case, where it just makes a lot of sense. UN Smart Maps is part of the UN OpenGIS initiative, it features a wide range of things, even an AI chatbot called TRIDENT that transforms the text into Overpass API calls. Try TRIDENT it out yourself, when you open the developer console, you can see the resulting Overpass API calls.
• Offline web map server “UNVT Portable”: This talk got into more detail about using Raspberry Pis to have map data stored in IPFS for offline use. It’s very similar to what I envision, the only difference is that I’d also like to keep the storage in the browser. But I surely see a future, where those efforts are combined, to have a small easy server you can deploy, with in browser copies of subsets of the data to be able to work completely offline in the field. The original UNVT Portable repository doesn’t use IPFS, but Smart Maps Bazaar does, which seems to be its successor.
• B6, Diagonal’s open source geospatial analysis engine: A presentation of the B6 tool for geospatial analysis for urban planning. It has a beautiful interface. I really like the idea of doing things directly on the map in a notebook-style way, where you perform certain steps after each other.
• Elephant in the room: A talk about how many resources to computations take? Do we always need it? It’s very hard, often impossible, to find out how environmentally friendly some cloud services are. One of the conclusions was that cheaper providers likely use less power, hence are harming the environment less. I would like if there would be better ways (e.g. it misses things like economies of scale of large providers), but I agree that this might be the best metric we currently have. And I also hope there will be more economic pressure to save resources.
• There was a closing keynote from Kyoung-Soo Eom, who was talking about his long journey in open source GIS, but also his history with Kosovo, where he was also on a mission in 1999. Quite inspiring.

My talk

My talk about Collaborative mapping without internet connectivity was about a browser based offline-first prototype that uses IPFS to enable replication to other peers. The project is called Colleemap and is dual-licensed under the MIT and Apache 2.0 license. Although I tried the demo bazillion times before my talk, it sadly didn’t work during my talk. Though, trying it later with various people, I was able to get 4 peers connected once. I even saw it working on a Windows machine. So it really works cross-platform.

For the future I hope to work closer with the people from the UN OpenGIS initiative, it would be great to combine it with their Raspberry Pi based prototype.

Things I’ve learnt

The Sentinel-2 satellite imagery is available from multiple sources, directly from Copernicus Open Access Hub or through cloud providers like AWS, Azure of Google Cloud. From the cloud providers you only get the level-2 data. They might use the original level-2 data or do their own atmospheric correction based on the level-1 data. Or even re-encode the data. So it’s hard to tell which kind of data you actually get.

As far as I know (please let me know if I’m wrong), there isn’t any mirror of the full level-1c data. You can only get it through the Copernicus Open Access Hub and there the older images are stored in the long term archive on tape, where it can take up to 24h for the data to be available for download (if it works).

Ideally, there would be a mirror of the full level-1c data (where the ESA would provide checksums of their files) and a level-2 version, where the exact process is openly published, so that you can verify how it was created. The problem is the storage cost. The current level-2 data is about 25 PiB, which leads to storage costs of over $500k USD a month if you would store it on AWS S3 Standard at the current pricing (I used the $0.021 per GB).

Final thoughts

It was great to meet Gresa and Valmir from the local organizing committee before the FOSS4G in March at the OSGeo German language chapter conference FOSSGIS in Berlin. That made it easy for me to connect to the event right from the start. If there’s one thing future FOSS4Gs should adapt, it’s the cheap on-site (or close by) accommodation. I think that shared bathrooms is also much smoother to have, if you know that everyone in the accommodation is from the conference. We had something similar with the BaseCamp in Bonn during the FOSS4G 2016 and the international code spring in 2018 during the FOSSGIS conference, where the whole place was rented for the time of the events.

Though, of course, I also missed some of my longtime FOSS4G friends I hadn’t seen in a long time. I hope you’re all doing well and will meet again soon.

Categories: en, IPFS, conference, geo