Explanation of all numbers/letter on radar screen please?

[Nightwolf]

Correct wording, IMO, would be:

 

#2: Target true heading (target bearing is 095 here, per #9)

#6: Target aspect angle (relative to nose, so 0° would be head-on)

 

I believe that the aspect angle is the difference between the noses of the two aircraft. 0 degrees would be a tail chase, and 180 is head on.

[jojo]

I believe that the aspect angle is the difference between the noses of the two aircraft. 0 degrees would be a tail chase, and 180 is head on.

 

This is what you have in the HUD.

In VTB this is 0 head on and 180 in tail chase.

[Dagger71]

The drawing respect horizontal and vertical scaling.

 

So with 2 lines scan (6°), if you tilt the scan zone -20°, any TDC range past roughly 16Nm will result in negative min and max altitude.

 

The numbers are matching in game...

 

 

Looks like you are right.

 

But noway, no how have I EVER got a track with a lower flying AC at 16nm out while flying even at 20K with a 20 degree antenna!, I have to lower my antenna almost to bottom limit to even get a simple track.

 

Also why does the min/max numbers change when moving TDC. The radar doesn't chase the TDC, so the numbers should be constant at level flight.

Edited December 18, 2017 by Dagger71

[jojo]

Look at the drawing, the green lines are diverging.

You are moving the TDC along those lines. The Max altitude is the top line, the min altitude is the lower line. So the farther is the TDC, the greater is the gap.

 

So no, min & max altitude of radar scan zone are not constant, it depends on range and orientation of the scan zone.

 

In my example, with the scan zone at -20°, you won't see anything pas 16Nm

But you can still lower to -60°.

 

The other thing to test is how far can you detect a threat in look down ?

I think you should be good to see any fighter below 30 to 40Nm in look down.

 

A good way to work with 2 fighters is one who looks down, the other who looks up, so you can see anything coming at you (+/60° scan, 4 lines).

To do so you use TDC min/ max altitude.

One fighter set the min altitude to current altitude (min = 30), the other the max altitude to current altitude (max = 30).

Then you can move TDC. As soon as min value is negative, it means you are effectively scanning down to the ground. But you don't need have both max and min value negative.

If your scan zone hits the ground at 20Nm, it's ok, because you're radar will have detected target already between 30 to 40Nm.

 

Then if you want to track them you will need to adjust the scan zone.

 

Also the radar is scanning at 100°/s, so it's close to 5s for a complete +/60° - 4 lines scan.

Depending on tactical situation, you can decrease to 2 lines and/ or +/- 30° to scan faster.

 

Maybe this kind of things are new for you, but once you understand, you can use it on any serious fighter sim (other DCS modules like F-15C, up to come Hornet, Tomcat, other flight sims).

Edited December 18, 2017 by jojo

[Dagger71]

Look at the drawing, the green lines are diverging.

You are moving the TDC along those lines. The Max altitude is the top line, the min altitude is the lower line. So the farther is the TDC, the greater is the gap.

 

So no, min & max altitude of radar scan zone are not constant, it depends on range and orientation of the scan zone.

 

In my example, with the scan zone at -20°, you won't see anything pas 16Nm

But you can still lower to -60°.

 

The other thing to test is how far can you detect a threat in look down ?

I think you should be good to see any fighter below 30 to 40Nm in look down.

 

A good way to work with 2 fighters is one who looks down, the other who looks up, so you can see anything coming at you (+/60° scan, 4 lines).

To do so you use TDC min/ max altitude.

One fighter set the min altitude to current altitude (min = 30), the other the max altitude to current altitude (max = 30).

Then you can move TDC. As soon as min value is negative, it means you are effectively scanning down to the ground. But you don't need have both max and min value negative.

If your scan zone hits the ground at 20Nm, it's ok, because you're radar will have detected target already between 30 to 40Nm.

 

Then if you want to track them you will need to adjust the scan zone.

 

Also the radar is scanning at 100°/s, so it's close to 5s for a complete +/60° - 4 lines scan.

Depending on tactical situation, you can decrease to 2 lines and/ or +/- 30° to scan faster.

 

Maybe this kind of things are new for you, but once you understand, you can use it on any serious fighter sim (other DCS modules like F-15C, up to come Hornet, Tomcat, other flight sims).

 

Actully makes a lot more sense. Wasn't really thinking about it.

Thanks

 

But have you noticed a problem with the RDI since last patch where you can't even get a simple track sometimes with a known contact.. your alt stragith ahead , Yesterday I even spotted the AC in front of me, i got lower raising nose to him .. nothing.

[grunf]

Looks like you are right.

 

But noway, no how have I EVER got a track with a lower flying AC at 16nm out while flying even at 20K with a 20 degree antenna!, I have to lower my antenna almost to bottom limit to even get a simple track.

 

Also why does the min/max numbers change when moving TDC. The radar doesn't chase the TDC, so the numbers should be constant at level flight.

Try "F-15C Radar Tool" if you're not sure how radar cone works. It's obviously made for F-15, but the principle is the same (min and max altitudes are placed on the left side of -f-15 radar). You can see how moving the antenna affects what the radar sees at different distances and altitudes.

[jojo]

Yeah, great tip :thumbup:

[D4n]

Thanks jojo, good tips in a 2-ship flight :)

[Ala12Rv-watermanpc]

Actully makes a lot more sense. Wasn't really thinking about it.

Thanks

 

But have you noticed a problem with the RDI since last patch where you can't even get a simple track sometimes with a known contact.. your alt stragith ahead , Yesterday I even spotted the AC in front of me, i got lower raising nose to him .. nothing.

 

Actually it happened to me yesterday!

 

Mig-29 head on, same altitudes, 4 lines centered from my altitude, HFR, 60º azimuth (don't remember distance but I guess something like 60/80 miles or so at the start)...after 7/8 minutes trying to find him nothing showed in my radar screen...then it apeared on my 6. Im pretty sure something odd happened as after starting the mission several times, I could find him always but that time I couldn't.

[=Pedro=]

Would you update the first post, Daniel ?

[D4n]

To what exactly, Pedro?

[Azrayen]

@ Daniel: I guess (and agree) with an update to correct meaning of numbers in your first post, because myst people will only refer to this first post.

#4 and #5 need updating. See answers from Jojo and myHelljumper (bottom page 1, top page 2) for correct meaning.

 

Regards :)

Edited December 19, 2017 by Azrayen

[D4n]

Updated! :) Thx everyone!

[=Pedro=]

Updated! :) Thx everyone!

 

Thank you, Daniel :thumbup:

[jaguara5]

You could also add, that the target's (heading) arrow length is proportional to his speed, and the ownship arrow to our speed

[Robin_Hood]

I believe that the aspect angle is the difference between the noses of the two aircraft. 0 degrees would be a tail chase, and 180 is head on.

Actually, both definitions exist. I believe the Navy uses (or used) that one.* But yes, the other one (head-on=180°) is the more widely used and logical. What I didn't realised is that, acording to jojo (didn't check), the Mirage actually uses both définitions, one on the HUD and the other on the VTB. Now that can be confusing. I imagine it has something to do with different thought process for intercept and close combat.

 

 

*: Can't find a solid reference now, unfortunately. I'd did notice that some official Brevity codes gives aspect definitions (HOT, FLANK, etc...) with both methods (ex: HOT is "CONTACT aspect stabilized at 160-180 degrees angle from tail or 0 – 20 degrees angle from nose." There must be a reason why they feel they have to give the angles from the nose.

EDIT: Found a reference, in CNATRA P825 - Air To Air Intercept Procédures (2010), Appendix C - Multiservice Brevity Codes

Edited December 20, 2017 by Robin_Hood

[jojo]

Hi Robin Hood,

 

I did the test with target flying opposite direction (target flying south, me flying north) and tracks 20Nm aside.

 

So I can confirm that reference for aspect angle in the M-2000C isn't the nose of fighter and target (fighter heading and target heading) but the target heading compared to fighter to target line (or radar lock line).

 

And yes HUD aspect angle and VTB aspect angle are complementary.

 

In the HUD, target flying toward you = 180, in the VTB = 0

Edited December 22, 2017 by jojo

[Nightwolf]

How odd that they would use both definitions in the same plane!

 

On the topic of the radar in the Mirage, can anyone explain what all the switches around the VTB do and how they could be used? I've looked around without much success, and they're not mentioned in the manual or Chuck's guide.

[jojo]

The only one which is active is "N", to change the waypoint used as Bullseye for radar cursor coordinates reference. (lower left corner of the screen).

 

The other one are not active in the module.

 

IRL it's used to input target position and flight parameters and it creates a fake contact on the radar screen. Not used that much anyway...

[baltic_dragon]

Thanks guys, some interesting info to add to the updated manual. So now I need to update the update :)

[SinusoidDelta]

Hi Robin Hood,

 

I did the test with target flying opposite direction (target flying south, me flying north) and tracks 20Nm aside.

 

So I can confirm that reference for aspect angle in the M-2000C isn't the nose of fighter and target (fighter heading and target heading) but the target heading compared to fighter to target line (or radar lock line).

 

And yes HUD aspect angle and VTB aspect angle are complementary.

 

In the HUD, target flying toward you = 180, in the VTB = 0

 

I believe the proper terminology is Angle Off Tail (AOT) while the HUD would be Aspect Angle