BarElevation and Avionics70.dll

[FrankD 7]

Hello modders,

 

in the Avionics.ini files, one can notice the parameters "BarElevation" for each radar mode available.

 

I'm not sure to really understand what it's referring to and what is the unit used.

 

Could anyone who know it for sure tell me more?

 

Best regards

[JediMaster 451]

Well I don't know what it does in the .ini file specifically, the bar is a unit of radar scan in altitude. Most radars scan straight out ahead, expanding in a cone up and down from the plane's nose. They scan back and forth in a bar pattern, usually 3 bars, left to right, move up, right to left, move up, left to right, move down, right to left, move down, left to right, etc. You can then manually adjust that bar pattern downwards or upwards so you scan only your altitude and below or yours and above, or just below, or just above, depending on how far you tilt it up and down.

 

Generally speaking scan modes use several bars (like the 3 I mentioned) but things like boresight are locked to just one, the one at your altitude.

 

I don't believe the bar can be adjusted manually in SF, TK probably puts that in the "too complex" category, but sims like Falcon 4 and even LOMAC let you do that. Otherwise, if you're cruising at 30,000 ft, a bandit could slip by right in front of you by flying at 1000 ft because your radar would be looking over its head.

Edited March 1, 2011 by JediMaster

[FrankD 7]

Thanks for providing this insight into the scan modes JediMaster.

 

In an _AVIONICS.INI file, for example, the F-15A one, here is what it looks like:

 

 

 

[RadarDisplaySearch]
RangeSetting=1,2,3,4,5
BarElevation[1]=1.50
BarElevation[2]=0.50
BarElevation[3]=-0.50
BarElevation[4]=-1.50
ScanRate=140
ScanBeamAngle=2.5
ScanArc=60

 

 

So, I assume that the radar first let its 2.5° wide beam ride the first bar at 1.50 apple for 60° from it's left limit to its right limit at 140° per second, then switch to the bar at 0.50 apple and so forth.

 

Now, in the same file, in the " section, the ElevationAngle are defined, "MaxElevationAngle=60" and "MinElevationAngle=-60" for the F-15A (APG-63, don't know which version).

 

If the apples are degrees too (since the parameter is named "BarElevation"), how the 120° sector is covered since the actually scanned area only cover 4 times 2.5°?

[JediMaster 451]

I wouldn't assume those units are in degrees or seconds necessarily. TK sometimes uses units of measurement that aren't obvious for these lines. It's quite possible that while scanarc is in degrees, scanbeamangle isn't! Bar elevation could likewise be anything.

 

What I would take from that is that the F-15 radar uses 4 bars in its scan. Also, bars often overlap a bit, so that there's no chance of a plane below one scan bar passing up just as the bar scans down. However, a standard scan will never cover the entire FOV of the radar because that would take too long. It would take a dozen bars or so to cover max down deflection of the dish to max up deflection. That's why in the more hardcore sims like F4 and LOMAC you can manually tilt the scan pattern to look far below or above you, but you do lose the ability to see the other side when you do that because the bar pattern/number of bars is preset for something like RWS or TWS.

 

As for elevation angle, when you lock up a target in STT mode, the radar will try and maintain that lock until the target passes outside the gimbal limits of the radar, which in this case seems to indicate is 60 degrees above or below centerline. It will thus turn the radar to an angle you may not be able to manually adjust it to look with TK's radar controls.

Normally the angle a radar can look left and right is referred to as azimuth, but I don't know if that is mentioned in the .ini.

 

 

[+EricJ 4,246]

Yep it is

[FrankD 7]

Thank you very much JediMaster for the clarification, it helps a lot.

 

As EricJ confirmed, in the avionics.ini, you can use the parameter "MaxAzimuthAngle" to set the lateral limits when used by the player, and, in the data.ini, the parameter "RadarAzimuthLimit" to set it for the AI.