Talk:UFO Detection

Removed sentance suggesting using the graphs to locate UFOs general area being a 'borderline exploit', after all your base could well come with a telephone so governments can call and tell you that their civilians have been reporting UFOs flying over their terrority. It would seem to be a fairly essential way of defending the rest of the world in the first month or two while you get other bases set up to detect more aliens anyway, otherwise your interceptor would have almost nothing to do with your piddling little single radar covering about 5% of the land surface, and missing half the UFOs that wander over that terrority for 10-12 hours anyway (let alone missing anything fast moving 90-95% of the time). Its not like it is something you want to be doing for long anyway, as its fairly fiddly to keep checking the graphs every hour or so for new contacts.

--Sfnhltb 15:01, 26 February 2007 (PST)

Added a load here - the detection rates are based on the values in BASE.DAT and some hex editted trials of game saves that bore out that the values there seemed to be percentages. As this value seems to not get increased by building extra radars, this would seem to indicate the suggestions that more than one of each type are useless, but the combo of 1 short/1 long is valid (until hyperwave of course). The range of short radars was done by testing at what point on the map UFOs could get to without disappearing (factoring in that they almost always disappear only when each 30 minutes is up, so positions between those times dont count as part of the range). This assumes that the point at which you lose contact is based on the same range as you can spot them, but I think this is a reasonable assumption.

Note I tried a few things to try to disprove these hypothesis, such as building 20+ large radars in all 8 bases - no clear increase in detection rate over a dozen or more reloads of the same time period (ran for about a day, just to let the existing UFOs move about, and see if any more were seen compared to a similar amount of runs with just 1 radar). Changing the BASE.DAT detection rates for short/long to 100 each saw an immediate increase in detection rate, so it seems these values are what is used by the geoscape. They reset when you complete a build of any new facility it that base, so you could have 100% radars if you wanted, but only if you dont build anything new (or remember to go back and re-edit any time you complete something). Of course if you are doing that, why not just edit a hyperwave decoder in...

--Sfnhltb 18:55, 26 February 2007 (PST)

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We really need to look at the Small and Large radar pages. Simply put, much of the information in-game doesn't agree with game file analysis. In fact, it normally is in direct disagreement with both game files and the Official Strategy Guide (OSG). Here's a table I drew up a long time ago to show the differences. Please note that the detection ranges listed in the OSG are 1/5 that of in-game, so we can back-calculate it's hypothetical range of 480.

Radar	Det. %	Det. Range	Sweep Rate
Small (in-game)	5%	300nm	10
Small (game file)	10%	1500nm (OSG)	30
Large (in-game)	5%	450nm	10
Large (game file)	20%	2250nm (OSG)	30
Hyperwave (in game)	100%	? (480)	DNA
Hyperwave (game file)	100%	2400nm (OSG)	30

--Zombie 19:35, 26 February 2007 (PST)

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I might have missed some of the discussion, but do UFOs leaving the tracking zone disappear and reappear on the half hour? I've always had the impression that they just dropped off and reappeared instantly the moment they cross into or out of the tracking area's borders.

Can we also work the phantom radar bug somewhere in here? The only reference of it so far has been on my talk page for yonks. I could never think of how to slip it in.

- NKF

One thing you might want to check with that bug is that it might go away when you complete any new build on the site, not just a new radar - as when I was playing with setting the radars to 100% detection rates, those got reset with a new build, whether it was another radar, or an alien containment facility (to take the example I happened to test).

If the game files suggest ranges of 1500 miles for the small radar, it then opens the reverse question - in practise I have definitely reguarly had previously detected UFOs move out to larger ranges than that, and wander around for an hour or two without dropping off, which happens almost always once they are outside something closer to 2000 miles. Maybe the detection is fixed to the number in the files, and tracking is an extra 33%. This would seem to make it less likely there is a size of UFO factor (although I guess small or medium might use it at 100%, and battleships might have a >100% factor to increase the range they can be detected in just as easily as having a reduction applied to the smaller craft). Cant really think of any decent way to test this either way though.

--Sfnhltb 21:29, 26 February 2007 (PST)