F-15 radar elevation

[Svend_Dellepude]

The F-15 radar will not slew up/down +/- 60°, like described in the manual, but rather +/- 35°.

 

With the TDC set at 10nm (60761.154856 ft) the top boundary, when slewed up, will only go 40000 feet above you. And the same when slewed down (bottom boundary 40K below).

 

So: 40000/60000 = 2/3, now put that line in a coordinatesystem and you should end up around 35°.

 

In STT it will track a target +/- 60° vertical.

Edited April 5, 2015 by Svend_Dellepude

[Bushmanni]

Radar cone also always covers 16k feet in vertical at 15nm distance regardless of elevation, ie. it gets more narrow at upper and lower elevations.

Edited April 5, 2015 by Bushmanni

[Svend_Dellepude]

You might be right, but you wouldn't be able to see much of a change at +/- 35° of elevation.

The cone height is according to my calculations about 7-8° high and that seems pretty consistent.

The manual says bar height is 2,5°, and then you would expect some overlap.

Edited April 5, 2015 by Svend_Dellepude

[Bushmanni]

When the elevation setting is centered to zero degrees, scan cone is 10 degrees high. I have calculated that the max elevation gives a +-35 degree limit to the cone edge. At max elevation the scan cone is only little over 7 degrees while it should be still 10 degrees. At 15nm this makes 7000 feet difference in covered altitude (16k feet vs 23k feet).

[SDsc0rch]

oh wow ----- very interesting

 

also, in VACQ, it appears it doesn't scan from 0-deg in front of you (true boresight) and upward 55-deg, it appears from the elev coverage indicators on the left side of the VSD that the lower limit is actually inclined upward somewhat ----- does anybody know about that?

[Svend_Dellepude]

you are right. ±35°, corrected in earlier posts.

[Svend_Dellepude]

oh wow ----- very interesting

 

also, in VACQ, it appears it doesn't scan from 0-deg in front of you (true boresight) and upward 55-deg, it appears from the elev coverage indicators on the left side of the VSD that the lower limit is actually inclined upward somewhat ----- does anybody know about that?

 

Numbers are wrong. I tested that too. It will lock on to a target right on your nose, but I'm not sure if it scans the entire 60° up.

 

Something weird happens to the lower boundary when you bank the aircraft too, but the radar seems to do what it's supposed to.

Edited April 5, 2015 by Svend_Dellepude

[Svend_Dellepude]

By the way. why is "bug" removed from the title?

[Bushmanni]

I should add that the narrowing beam at extreme elevations has most relevance on horizontal coverage which gets very narrow even if properly modeled. With this bug it's even more narrow.