Recent diary entries
Prague Institute of Planning and Development is an organisation representing the city in spatial planning matters. They publish vast amounts of data through the website Geoportal under CC BY-SA 4.0, including regularly-updated high-resolution aerial imagery of the entire city.
Just over a year ago I noticed that there were some attempts to negotiate a permission to use their imagery for OSM, but the last news from that front was almost a year old. Being the sort of a person who tends to ask questions first and ask questions later, I decided to write them an email to find out what state were the negotiations in.
I listened to their reasons for keeping the data under CC BY-SA 4.0 and a few reassuring emails later I received an email containing the following:
"IPR Praha souhlasí s využíváním ortofotografií, které poskytuje prostřednictvím Geoportálu hl. m. Prahy, za účelem aktualizace a doplňování databáze OpenStreetMap, přičemž vzniklá vektorová data smí být vložena do OSM pod licencí ODbL za předpokladu, že IPR bude uveden v seznamu přispěvatelů do OSM a takto vzniklá data budou mít IPR uveden jako svůj zdroj."
A simplified translation for the non-Czech-speakers out there:
"[The Institute] agrees with the use of aerial imagery provided through [the website] for OSM. Resulting vector data may be published by OSM under ODbL provided that [the Institute] will be listed among the contributors to OSM and the data will list the appropriate source."
Needless to say I had the contributors wiki-page edited almost immediately. And so we got ourselves some very shiny imagery to use.
This January I had a look at the list of changesets and found that, in 2017 alone, at least 27 users used the imagery for a total of over 500 changesets and causing over 56 thousand map changes. When I wrote back to the Institute to share these stats with them, the resulting conversation ended with the granting of a general permission to use any of the CC BY-SA 4.0 data from the Geoportal website under the same conditions.
And that is the story of how OSM got its access to a lot of data for Prague.
I'd like to thank Prague Institute of Planning and Development for their generosity. We are grateful for this data and even I am curious as to what we can make with them.