So, here's what I have. Since the map has at least a "J" quadrant, then it must have at least 10 "East to west" quadrants. (A-J) and I'm assuming that it's a square map, so it would also have 10 "North to south" quadrants.
Next, I need to know how big a quadrant is. Thanks to the screenshot, we know that the player Mech and the Catapult are about 60m apart, so using the distance shown on the minimap, we can get an idea of how far 60m is on the map. (That is the small red line.)
As for the quadrant itself, that seems to be 5 segments of 60m long, which is 300m.
And since the map is at least 10x10 quadrants, that makes the map at least 3km x 3km.
Now, how big is that? Well, at top speed, it would take an Atlas 4.7 minutes to walk corner to corner. A Jenner, at 118km/h could do that in 2.15 minutes. Of course, you're likely to hit an enemy before you get all the way across the map, so an Atlas would likely take somewhere around 2 minutes to get within fighting distance of the middle of the map, assuming it started in a corner.
This seems a little smaller than I'd prefer, but it's also not a "10 seconds in and we're all bunched in the center" kind of deal either. There is quite a bit of room for hiding and ambushing, and things of that sort.
One final note, my size assumes that "J" is the last quadrant, since it is the last one we can see on the minimap. Which means that this fight is taking place in the far East side of the map. If this screenshot is actually the center of the map, the quadrants might go beyond "J", so the map could easily be more like 5-6km on a side. It would take an Atlas nearly 8 minutes to walk corner-to-corner in a 5km square map.
EDIT: I went looking, and I found that "J" is indeed the last quadrant. This screenshot shows that the map ends at "J", so this map is likely a 3km square:
Edited by Vorus, 01 June 2012 - 07:13 AM.