Hydrant Radar

A map of nearby fire hydrants and other stuff

Intent

• Simple website that shows firefighting equipment nearby.
• By default, GPS tracking is enabled, giving you a virtual radar view with variable zoom.
• You can disable GPS tracking using the button in the top right corner, allowing you to pan and zoom to your target in advance.
• Made from a German perspective, but meant to work worldwide, even if symbols or units (mm) don't match for now.

Features

• Circles show you important distances:
  • Grey: 20 m (standard "B" length)
  • Red: 100 m (standard reel length)
  • Black: 500 m (standard container for long distances)
• If you enable survey mode ("Zensus"), the circles will disappear and all POIs with sufficient data will become partially transparent. This allows you to see at a glance, which hydrants need additional information.
• Survey mode also shows you a button for exporting all POIs in the viewport into a single CSV file.

Technology

• Uses the default OSM map, using https://leafletjs.com/index.html
• Queries POIs directly from the Overpass API, so updates are visible within minutes!

Configuration

Depending on your weakest mobile device in use, you may want to set the following two values in the code:

• latLonRange: The number of degrees vertically and half of this horizontally in which hydrants are loaded around the viewed position.
• movementLimit: The number of degrees vertically and half of this horizontally that you have to move away from the last loading position for the app to load hydrants again.

The movementLimit should be about half of latLonRange.