SignalMap
About this project
Jan 2026 – now · Developer, then maintainer · team of 4
A mobile coverage map of Réunion and Mayotte: click anywhere and see the signal you would get from about 3,100 antennas.
Réunion and Mayotte, two French overseas departments, have about 3,100 mobile antennas between them. SignalMap puts them all on one map and answers three questions:
- What signal would I get standing here? Click anywhere and see the strength and the number of bars, per operator and per generation, from 2G to 5G.
- Where are the antennas, and which are down? Every site is pinned on the map, with the current outages.
- Where should a new antenna go? The map suggests sites where people are least well served.
It started as a one-week school project with a team of four in January 2026. I carried it on afterwards, and in September 2026 it became something that can be deployed and kept running, not just a demo.
How it works
Working out the signal at a point takes a lot of computation over the terrain, too slow to do on each click. So the coverage of every antenna is computed once, ahead of time, and saved as a picture of signal strengths. A click then only reads a few pixels, and the answer comes back instantly.
What I took from it
- Moving heavy work out of the moment someone clicks, into a step done ahead of time, is often the best fix for both speed and safety.
- Writing down why things are the way they are, in a guide for the next person, is as much a part of the product as the code.
