Its main purpose is to measure things and estimate time of arrival.
The Distance between one node to the next horizontally or vertically is the following traveltime of a specific unit:
- Bomber: 120sec/2min
Nuke: about 60sec/1min
Battleship/Carrier: 200sec/3:20min or 3nodes in 10min
Sub: 285sec/4:45min or 4nodes in 19min
The actual nuke traveltime is a little vague. While it needs a little more then 60sec on short distances, its traveltime will shorten if its arc goes near the upper map boundary. A short test showed about 2min shorten traveltime when flying a maximum distance from asia to north america (about 35min total). So 60sec is a ok approximation.
To get times of non vertical or horizontal movement , one would use Pythagoras
travelgrid.zip - unzip into your Defcon folder
An interesting side effect: The grid is actually shown on the globe in the start screen, once activated
UPDATE:
I added coordinates to the nodes.
The coordinates are basicly longitude/latitude. They are also the internal used coordinates (e.g. for bot programing). But I divided them by 6 to keep numbers small. If anyone needs a modification of this, just say so.
travelgrid_coordinates.zip