Talk:Small Radar System

Investigation of radar ranges

Well, I started doing some testing of what the actual range of each radar system is, and it's extremely strange. A Small Radar system (the initial base's default) detected UFOs as far as 1300 nautical miles away. (I measured on a globe, using points corresponding to what was displayed on the Geoscape.)

Once detected, UFOs could be tracked as far as 2000-2500 nautical miles away, and with a Large Radar or Hyper-Wave Decoder, the tracking limit seemed to be 3000-3500 nautical miles. For all I know, the tracking limit may be the same as the detection limit, and I just didn't detect any UFOs while they were at the outer edge.

The detection range for ships (I only tested an Interceptor) seemed to be about 450-500 nautical miles.

It is safe to say radar ranges are nothing like what is described in the game.

--Ethereal Cereal 19:52, 31 May 2006 (PDT)

You did remember to vary the radar site positioning for testing? [The internal modeling is skewed by latitude...near equator and poles are not that distorted geometrically (near circle), but the range is hyper near the Arctic and Antarctic circles.]

--Zaimoni 11:18, 1 Jun 2006 (EDT)

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Actually, I used Budapest as the base site each time. Not an equatorial latitude, but geometric distortion alone cannot account for ranges several times greater than 300 or 450 miles -- Interceptors alone had a detection range of about 500 miles, and bases much, much, further than that.

I'm not positive, but I got the sense that craft have a 100% detection rate when within range of a UFO.

On the basis of this, it's not clear what coverage strategy should be adopted -- although the existing strategy of one base per continent holds up well, especially once you've got Hyper-Wave Decoders.

--Ethereal Cereal 11:27, 1 June 2006 (PDT)

The radar ranges might be fixed for both detection, and retention, but you have to figure in that the UFO has 0-29 minutes of wandering about your territory before it can be spotted due to the infrequent detection interval, and this is combined with that on exit they can have left your radar range for up to 29 minutes as well before it notices and blinks them out makes it tough. Still you may be right about it only detecting at 2/3 or 3/4 of its tracking range as well, I certainly noticed that new hits seemed to be closer and thought it was just the above, but UFOs have enough wandering about laterally to my base once they are detected that you would think you would get the occasional further out contact.

One possibility is that the UFO size factors in here - anything smaller than a battleship might have a % factor that reduces their initial contact range for both short and long radars (and hyperwaves? hard to say), but once you have them you can follow even the small contacts back out up until you get to your hard cap. Sounds feasible? I guess to test you would want a save when you know a battleship is wandering about, you have one base, and repeat many times to see if you can get a longer range contact. If so this would suggest the stuff about the size affecting detection is accurate, and also explain why most are seen neared (especially on new start testing where mostly small UFOs are bumping around).

Probably not all that surprising but my base for most of the testing of a single site was in/near Budapest as well. Its likely that many bases will be around this latitude anyway, as a normal tactic would seem to be to have 3 northern/3 southern bases each on a different continent to get a good overall coverage of all the countries, and hence part of your cash supply. I might try single Equatorial and Polar bases and see if it makes any noticeable difference, but the numbers I put up are fairly rough anyway (as you have limited data points which you have to approximate, and then you are drawing a circle in Paint on a 2D representation of a sphere so you have to ensure the base is centralised to avoid you actually drawing some weird obloid shape when projected onto the globe, etc).

--Sfnhltb 19:36, 26 February 2007 (PST)

Looking at my figures from months ago, I would wager that "tracking" range is simply 150% that of detection range:

          Detect.     Track
Sm. Radar   1500     2000-2500 (150% = 2250)
Lg. Radar   2250     3000-3500 (150% = 3375)

Also of interest is this old Strategycore thread I came across yesterday. Separately, there's the question of craft radar range. If, like you theorize, re-detection is 100% and occurs at tracking range, then craft radar is probably about 300nm (and tracking 450nm). If their initial detection rate is 100%, then their detection range should be 500nm (and tracking 750nm).

This should be easy enough to test: when do UFOs being chased by craft disappear again? At 500nm or 750nm?--Ethereal Cereal 01:24, 27 February 2007 (PST)

--Ethereal Cereal 01:24, 27 February 2007 (PST)

Well I'm not sure its easy to test, remember with the 30 min check interval its quite feasible for a craft you have turned back or was low fuel to manage to be 5000 miles from a fast UFO when the radar blip actually goes, if you turn back at the right time.

--Sfnhltb 02:38, 27 February 2007 (PST)

Did some more testing. I see what you mean with the 30-minute check, some UFOs got very far away from a craft (and nowhere near a base radar) before disappearing on the half hour. I also saw craft that disappeared well within radar range before the half hour, presumably who left the atmosphere spontaneously. I also saw fast UFOs well within base-radar detection range being redetected on the half hour.

I got the sense that "redetection" range (lost on one radar, picked up later on another) uses detection range, not tracking range. (This of course requries more observation.) That would mean that craft (re)detection range is 500. As for testing if craft-based tracking range is 750, that should be measurable in cases where the UFO is travelling only slightly faster than the craft, and not within range of a base radar. I tried testing this a bit but haven't gotten conclusive results yet.--Ethereal Cereal 17:00, 27 February 2007 (PST)

I just tried a more controlled set of tests: craft range to detect an alien base. Inching a patrolling craft towards the site, I determined that the maximum detection range was 900nm. The range was the same for Interceptors or Skyrangers (I didn't try Avengers, etc.). The detections did not always occur on the half hour, and were at least partly dependent on distance: patrolling right over the base, detection was almost immediate, never taking more than an hour; detection at the outer edge was almost immediate once or twice, but usually took a few hours of patrolling. Moving craft couldn't detect a base at all, even while flying back and forth directly above it.--Ethereal Cereal 22:26, 28 February 2007 (PST)

And finally, I had an Interceptor chase a small scout (2100 vs. 2200). The final radar blip before tracking was lost was never more than 400nm. Provided craft have separate trackng and detection radii, I'd be inclined to believe craft detection range is 250nm and tracking range is 375nm. If it uses the same figure for both detection and tracking, range is probably 400nm.--Ethereal Cereal 23:13, 28 February 2007 (PST)

And finally-finally, I had a skyranger patrol in a region where I knew a UFO was based on prior savegames (it was not yet detected by any means). The skyranger first picked it up in the mid-to-high 300nm range in repeated trials. So it looks like craft UFO detection and tracking ranges are both 400nm, and base detection is 900nm.--Ethereal Cereal 23:41, 28 February 2007 (PST)

I have to recalibrate my figures. I still got the same # of pixels distance, but my nm-conversion factor was wrong. Base detection range is about 1600 nm, and UFO detection/tracking range about 700. I wish I could fudge the numbers to say 1500 and 750, but if anything, they were slightly above 1600 and slightly below 700.--Ethereal Cereal 17:54, 1 March 2007 (PST)

I did a brief test that fell into my lap yesterday - I was watching ALIEN.DAT regularly and saw a craft on a direct line to Europe (SAm, Brazil, NAtl, Europe) and it was repeating this every time so it was on some well targetted mission. I went back to the start and sent out my interceptor to try and catch it while outside base radar range while it was still undetected. Once I got the angle to send the interceptor out right, I could repeatedly (12-15 times in a row before I got bored) catch the UFO every time with the Interceptors radar as he passed a point in the mid atlantic way out of my bases range, so it would seem that craft have a 100% or near perfect detection rate even for undetected UFOs (in the air at least), might need to patrol to see grounded ones, like with bases?).

--Sfnhltb 00:04, 1 March 2007 (PST)

That's what I like about Base Nigeria. Use the graphs to figure out where the UFO is, then send Interceptor to find it with Skyranger immediately behind. [Skyranger finds UFOs beyond Interceptor range...Australia and Siberia are noxious, Arctic and Antarctica are iffy with Interceptor from Base Nigeria.]

--Zaimoni 09:34, 1 March 2007 (CST)

I found Interceptor and Skyranger UFO detection ranges to be the same. It may be that since Interceptors move faster, they'll usually be closer to a UFO when the 30-minute mark hits and the detection is "performed".--Ethereal Cereal 17:54, 1 March 2007 (PST)