How big is this project? Moon-sighting website


Hope this is the right place for this: please let me know if not.

I have an idea that I think OSM would be ideal for. I’m hoping people can let me know

  • whether they think so too
  • how many hours of development it might involve
  • how much it might cost if I can find funding to produce it

Muslims look for the first crescent of the lunar month, especially for the beginning and end of Ramadan. There’s always excitement about it - and usually controversy, too.

Minimum viable solution
A website that allows you to record your sighting of the first crescent using your phone: time, location, weather conditions, etc.
Like this one run by the UK Almanac Office, but with open data.

These go on a map. The map can replay the sightings in stop-motion, so you see them appear in the order they were reported. (This is important for finding false positives).

Further ideas
Registration of observers.
Ranking system for ‘trusted’ and ‘most trusted’ observers.
Blockchain or other technology to ‘sign’ reports securely.
Spoof-proofing of location & time reports.
Corroboration system to prove you were with other registered observers when you saw the crescent.

Any ideas very gladly received! Thanks,


I guess that you could use OSM data to create a map layer that shows someone their location, but that’s only a very small part of what you envisage.

Ah, I was assuming there was some wider open data substructure to OSM that I could use for much of the rest.
(Critical that it’s all “open”, for reasons of transparency and so verifiability )

Sorry, am completely ignorant of the principles behind anything computery.

What about cross-hairs to manually select your location? Would the map help there?

About 10 years ago I was involved in a “help the community” effort run by one of the main mobile phone hardware and software suppliers. For that I actually used OSM-based services for some bits (hosted by Mapquest, actually) because they were better documented and had more features than the “official” services provided natively on the phone. The query that used OSM for was essentially “what’s the street address for my current location”.

In your case it sounds like you just want a website / phone app with certain features. Some of these features may be shared with software that does things with OSM data (perhaps “report my current location as a latitude and longitude” and “display a map with a certain latitude and longitude”), but most won’t be - all the stuff associated with storing individual reports on a server somewhere, and designing forms for people to fill in on a website or via a phone to capture the data that you’re interested in.

It is possible to create something like this with essentially no up-front experience, providing you can get a bit of help along the way (the development of the app I was involved with 10 years ago was conceived and developed by people with no previous app development experience). What I’d suggest is to try and break the problem down into small portions and find a way of solving each of those small pieces. In many cases there will be libraries and frameworks available for solving whole sections of the problem. To take just one example “display a location on a map” is something that you can do with a javascript library called “leaflet”: There will be others for the other sections too. There’s lots more assistance available online now than there was previously too (a quick web search suggests about 2.5 billion hits for “my first javascript website”).

If you don’t want to develop it yourself, or want help with the planning or development then there are dozens of companies that are set up to do exactly that. has a section about OSM development services, but to be honest most of what you want isn’t OSM- or geo-related, so you probably don’t need that level of expertise.

That all sounds like useful advice. This bit

sounds especially sensible, given that the project will probably go in fits and starts as there’s funding and time to deal with it.

Thank you.