Air to Ground Ranging (AGR)

[imacken]

Can someone explain a couple of things relating to AGR?

 

Wags said:

'Air-to-ground ranging (AGR) mode is an indirect radar mode—it is commanded automatically by the MC when deemed necessary and cannot be directly selected. Its purpose is to provide slant range to an aimpoint to allow a more precise calculation of altitude above target. When commanded, the AGR legend will appear on the HUD and the RDR ATTK format will display the AGR sub-format. If the radar was operating in MAP mode, it's possible to exit AGR mode and return to MAP by assigning TDC priority to the RDR ATTK format.'

 

1) does this mean AGR is on all the time?

2) if so, what is the point in doing SCS forward to display AGR on the HUD and on the right DDI?

3) what difference does it make?

 

Thanks.

[Fri13]

Not all the time, as said.

And this will help as well to understand, something Wags posted this year:

 

[imacken]

Thanks for that, but I'm still confused.

So, if it's not activated all the time in a AG attack, then why not? I mean, if it is there to improve accuracy - 'a more precise calculation' - then why would it not be on?

Also, if it is not on, then does SCS forward switch it on manually? Or, does SCS forward not do anything if it is not switched on by MC? If the former, then that seems to fly in the face of Wags' statement 'it is commanded automatically by the MC when deemed necessary and cannot be directly selected'. If the latter, then why does AGR always appear with SCS forward?

[Swift.]

Think about why AGR would be used. So that the MC can generate a precise TGT or so that it can calculate CCIP right?

 

Now think about what you are doing when you SCS forward, the only thing I can think of is to designate a new TGT using the HUD.

 

So that's why SCS forward will command AGR, because the only time you SCS forward, is when you need AGR to measure the range to your newly designated point.

 

As for the other cases, I guess the MC will decide whether it needs it for CCIP solutions perhaps, not sure how hornet does that precisely.

[imacken]

Sorry, but I don't understand.

Why would the MC use AGR to designate a new target? SCS forward doesn't designate a new target, it just brings up the AGR data on the DDI and shows AGR on the HUD.

My question still stands, why would AGR not be on all the time if it improves accuracy?

 

[AvroLanc]

Sorry, but I don't understand.

Why would the MC use AGR to designate a new target? SCS forward doesn't designate a new target, it just brings up the AGR data on the DDI and shows AGR on the HUD.

My question still stands, why would AGR not be on all the time if it improves accuracy?

 

AGR isn't really needed to designate a new TGT as such. It's used to provide the slant range for the bombing calculation. Hence the name. SCS forward sort of has two functions. It assigns the TDC to the HUD to enable slewing AND commands AGR. You need AGR when slewing in order to correctly range the visual line of sight you're aiming at. AGR is more accurate than a pure BARO or RAD ALT calculation.

 

AGR isn't used all the time because it's only 1 of many ranging methods. The most appropriate of which is used depending on the situation. If you've used the A/G Radar MAP or Expand function to designate a TGT, then ranging taken from that (along with INS information). Likewise if you've got a FTT with the radar from either MAP or GMT.

If you've used the TGP and the Laser, then this provides a very good, the best in fact, ranging solution.

 

I believe the MC should command AGR in a few more situations than what we have atm. One maybe, when the FLIR is initially command to Area track.

[imacken]

Sure, so are we saying that AGR is always on for non-designated situations like rockets, guns and CCIP bombs for example.

[AvroLanc]

Sure, so are we saying that AGR is always on for non-designated situations like rockets, guns and CCIP bombs for example.

 

No it shouldn’t be. Only if you assign TDC to HUD. Which is the manual way of commanding AGR.

You can also command it during an AUTO (TGT Designated) situation, as a more accurate ranging compared to BARO or RAD.

[Swift.]

No idea how it gets range/alt data for CCIP in hornet TBH. Might be Baro, might be Radalt, might be DTED (even though ED say our hornet shouldnt have that), might be AGR

[imacken]

But, Wags says 'it is commanded automatically by the MC when deemed necessary and cannot be directly selected'. Sorry, but I am confused. either it is selectable or it is automatic. Wags suggests it is automatic. AFAICS selecting SCS forward just displays it on the HUD/DDI. No real purpose, unless I am misunderstanding.

[maxTRX]

But, Wags says 'it is commanded automatically by the MC when deemed necessary and cannot be directly selected'. Sorry, but I am confused. either it is selectable or it is automatic. Wags suggests it is automatic. AFAICS selecting SCS forward just displays it on the HUD/DDI. No real purpose, unless I am misunderstanding.

 

I'm not sure what's 'automatic' in it's implementation. Its range is roughly 10nm and it is sort of an equivalent of ACM in A/A and it does have auto-acquisition mode (hopefully implemented later).

It still has to be invoked by TDC > HUD as far as I know or... as far as I don't know;)

[Preendog]

In testing testerday, I found AGR on and off has different CCIP pipper behaviour. AGR off uses current RADALT. AGR on acts like a raycast from the plane to the CCIP.

 

If the ground radar is sweeping, AGR is off. If you see the AGR screen with the range numbers, it is on.

 

The lore is often misleading, it is prudent to ignore it and test for the real behavior in game.

[imacken]

In testing testerday, I found AGR on and off has different CCIP pipper behaviour. AGR off uses current RADALT. AGR on acts like a raycast from the plane to the CCIP.

 

If the ground radar is sweeping, AGR is off. If you see the AGR screen with the range numbers, it is on.

 

The lore is often misleading, it is prudent to ignore it and test for the real behavior in game.

 

But that flies in the face of what Wags said. You only see the AGR screen if you press SCS forward. Wags quite categorically said that AGR cannot be directly selected and that it is commanded automatically. My take is that it is always on, and all that pressing SCS forward does is display the data that is already being used internally.

[Swift.]

What Wags said is that it is commanded when the MC deems it necessary. That is not a contradiction to what we are saying, as we are saying the MC will deem it necessary when you are doing a HUD designation or when you are doing CCIP, hence the ability to 'command' AGR by pressing SCS forward. You aren't directly turning AGR on, you are simply doing an action that will require the MC to use AGR.

 

As a side note, its not a good policy to take Wags' words as gospel, he can be and is wrong from time to time.

[imacken]

What Wags said is that it is commanded when the MC deems it necessary. That is not a contradiction to what we are saying, as we are saying the MC will deem it necessary when you are doing a HUD designation or when you are doing CCIP, hence the ability to 'command' AGR by pressing SCS forward. You aren't directly turning AGR on, you are simply doing an action that will require the MC to use AGR.

 

As a side note, its not a good policy to take Wags' words as gospel, he can be and is wrong from time to time.

 

Thanks to everyone here, but I am no clearer despite all the helpful contributions.

You say during a CCIP run the MC will deem it necessary to use AGR and it does that automatically. Ok, I can see that. What I still don't see is what pressing SCS forward actually does in a CCIP run, if the MC has already invoked AGR. Seems to me it is just displaying what it is already using internally.

[Santi871]

On a side note something that needs to be reported is that CCIP symbology should only be displayed if the TDC is assigned to the HUD.

[imacken]

OK, I think I've worked it out, thanks to a comment posted on the Reapers video page here

 

They had the same questions as I had and a guy posted a really useful comment. I tested what he said, and it works.

 

Just below the altitude box on the HUD, you will see a letter. If in CCIP, for example, that changes depending on the conditions. It shows:

R or B if radar or barometric altitude is being used, or A if AGR is being used.

 

 

Now, A kicks in automatically if the dive angle is greater than approximately 7 degrees. Or, if less than 7 degrees, it can be forced on by SCS forward.

 

So, I think I have my answer, it is invoked automatically, and we don't have to press SCS forward under certain conditions.

[Swift.]

On a side note something that needs to be reported is that CCIP symbology should only be displayed if the TDC is assigned to the HUD.

 

Santi, I have a bug to report: CCIP symbology should only show when TDC is assigned to the HUD ;)

[maxTRX]

OK, I think I've worked it out, thanks to a comment posted on the Reapers video page here

 

They had the same questions as I had and a guy posted a really useful comment. I tested what he said, and it works.

 

Just below the altitude box on the HUD, you will see a letter. If in CCIP, for example, that changes depending on the conditions. It shows:

R or B if radar or barometric altitude is being used, or A if AGR is being used.

 

 

Now, A kicks in automatically if the dive angle is greater than approximately 7 degrees. Or, if less than 7 degrees, it can be forced on by SCS forward.

 

So, I think I have my answer, it is invoked automatically, and we don't have to press SCS forward under certain conditions.

 

Now, I'm confused...

[maxTRX]

 

Santi, I have a bug to report: CCIP symbology should only show when TDC is assigned to the HUD ;)

 

I hope I'm reading this 'wink, wink' correctly:book:

[maxTRX]

 

Now, I'm confused...

 

Well, I'm getting there. I checked some loose tidbits of info from the other sim. Apparently AGR can be commanded by MC as long as the radar is on. It could run in 'designated' (target LOS) and 'un-designated' mode (following reticles/cursors) not only on HUD but also FLIR and LST. I guess when you place TDC on HUD when in AUTO or CCIP it simply shows that AGR is on HUD, whether designated or undesignated. It can be rejected though if you just want to use weapon ballistic data + altitude from radar altimeter (or whatever else;)) for CCIP. I'll do some testing in the sim later but from what I've seen so far, this little letter below the altitude box on HUD shows up only for bombs not for A/G gun. It shows 'A' when AGR is enabled and 'R' when radar altimeter is used. 'R' only shows up below 5k ft. if you're not using AGR, regardless of the position of ALT switch. Interestingly enough if you're above 5k ft. and not using AGR via HUD the MC shows 'A' anyway then below 5k it changes to 'R'. It all sounds chaotic but we'll get there eventually...

I stumbled on a interesting note regarding A/G gun. When you have it selected with AGR, the Max range is set according to AGR and other factors. When AGR is rejected by pressing 'cage/uncage', the Max range mark on the reticle is set to 5k feet. That's for the Rhino though...

[LastRifleRound]

OK, I think I've worked it out, thanks to a comment posted on the Reapers video page here

 

They had the same questions as I had and a guy posted a really useful comment. I tested what he said, and it works.

 

Just below the altitude box on the HUD, you will see a letter. If in CCIP, for example, that changes depending on the conditions. It shows:

R or B if radar or barometric altitude is being used, or A if AGR is being used.

 

 

Now, A kicks in automatically if the dive angle is greater than approximately 7 degrees. Or, if less than 7 degrees, it can be forced on by SCS forward.

 

So, I think I have my answer, it is invoked automatically, and we don't have to press SCS forward under certain conditions.

 

This seems to be the current behavior in sim.

 

I believe also it is commanded when using the HUD to slew the TD box (reported by swift earlier that this should be possible in all modes, not just with AUTO selected and no active designation as it is now), so again, when SCS up is commanded.

 

Imagine you have designated an area target using the radar or WPDSG on some imprecise coordinates and are running in to drop some GP's in AUTO. On the dive, you'd SCS up so you can "sweeten" up the designation as you get visual. Any time you stop slewing, the radar takes the range at the point of the TD box and uses it for slant range. This isn't currently possible in DCS but should be.

[imacken]

 

I'll do some testing in the sim later but from what I've seen so far, this little letter below the altitude box on HUD shows up only for bombs not for A/G gun. It shows 'A' when AGR is enabled and 'R' when radar altimeter is used. 'R' only shows up below 5k ft. if you're not using AGR, regardless of the position of ALT switch. Interestingly enough if you're above 5k ft. and not using AGR via HUD the MC shows 'A' anyway then below 5k it changes to 'R'. It all sounds chaotic but we'll get there eventually...

I stumbled on a interesting note regarding A/G gun. When you have it selected with AGR, the Max range is set according to AGR and other factors. When AGR is rejected by pressing 'cage/uncage', the Max range mark on the reticle is set to 5k feet. That's for the Rhino though...

 

Not totally correct from what I can see.

1) If barometric altitude is set, then it's as you say, no letter until either you go below 5k - when a R appears - or dive angle is greater than approx 7 degrees - when an A appears.

2) If radar altitude is set, you get a B above 5k and a R below. The A appears when dive is greater than approx. 7degrees (or if you do a SCS forward).

3) yes, A only appears for bombs and not for guns/rockets. (I wonder why?)

 

The A only shows up when you are in a dive. I wonder if this has something to do with AUTO as you are likely to be in level flight for that.

 

I still am wondering what practical use this all is!

[Swift.]

The practical use of AGR? Accurate CCIP (or just CCIP in general as Santi said)

[AvroLanc]

 

 

The A only shows up when you are in a dive. I wonder if this has something to do with AUTO as you are likely to be in level flight for that.

 

I still am wondering what practical use this all is!

 

A only shows in a dive because the radar dish needs to be pointing down to see the ground. Obviously it can gimbal a certain amount, but it helps if the nose is pointed in the right direction.

 

The practical use is accurate ranging and therefore more accurate CCIP and AUTO. Whether or not that difference is modeled correctly in sim is still up for debate. The greatest difference / effect should be when either BARO or RAD ALT ranging can't be relied on.

 

In the case of RAD ALT, the height directly down under the aircraft at time of release should equal the height above the target at time of release. If you're over undulating / mountainous terrain, they won't equal. In this case AGR would be of most benefit. Should be the easier to test in sim.

 

In the case of BARO, the target elevation needs to be correct. Not sure if it takes current WP elevation or a DTED type calculation (not even sure DTED is in our sim, but the Jury's out). ED might have simplified this anyway. Slightly harder to test.