STT Lock Caribrated Air Speed.

[crow0827]

Happy new year, everyone.

 

I have a question if it is bug or not.

 

Please see below.

On the STT mode, Target Caribrated Air Speed is displayed on near of OSB 4.

My friends noticed that the number is same as aircraft outside view's TAS indication.

 

In the aircraft manual(ED and real manual), it is expressed Target Caribrated Air Speed.

 

Which is correct TAS or CAS?

 

 

[Dee-Jay]

Hi!

It has to be a CAS.

Regards.

[Frederf]

It can't. It's a TAS (or even GS) fudged as a pseudo CAS. CAS is indicative of maneuver potential so knowing the target's CAS is a good indication of what he can do maneuver wise.

[Dee-Jay]

Radar knows its own speed, alt, ground track, heading, temp ... etc ... it measures TGT relative speed, "aspect", trajectory, atl ... with all those info, system can calculate a CAS.

[TheBigTatanka]

It has to be Ground Speed. Same as TAS with no winds. It's valuable info.

[Dee-Jay]

It has to be Ground Speed. Same as TAS with no winds. It's valuable info.

Tell it to Lockheehd Martin ;)

[Geraki]

in addition to that the +/- symbol must occur in closure rate e.g +896K or -896K

[crow0827]

LOL. We all have different ways of thinking.

I need ED’s opinion or reliable documentation.

 

Just my understanding, GS, TAS is easy to calculate from RADAR Info more than CAS.

Edited January 8, 2020 by crow0827

[Dee-Jay]

or reliable documentation.

 

Calibrated Airspeed for Bugged Target is displayed in 10-knot increments below the OVRD mnemonic.

You can check by yourself if you have such documentation.

[crow0827]

Calibrated Airspeed for Bugged Target is displayed in 10-knot increments below the OVRD mnemonic.

You can check by yourself if you have such documentation.

 

Happy new year, everyone.

 

I have a question if it is bug or not.

 

Please see below.

On the STT mode, Target Caribrated Air Speed is displayed on near of OSB 4.

My friends noticed that the number is same as aircraft outside view's TAS indication.

 

In the aircraft manual(ED and real manual), it is expressed Target Caribrated Air Speed.

 

Which is correct TAS or CAS?

 

 

 

I read the sentence as mentioned.

 

Other reliable documents.

Thanks.

[Dee-Jay]

sorry ... I don't understand what you mean (?) ...

It is written black on white several time on -34 ... so ... I don't see how ED could say something different if they refer and use RL documents for development.

[crow0827]

In game behavior is different from RL.

Thus I said “ED or other reliable documents” and tagged “bug” this thread.

Don’t let me explain all.

 

1. Why ED use TAS number?

2. If implementation as mentioned above, what is source of implementation?

That’s all.

[Frederf]

Of course a smart person reads document that radar displays target CAS and makes obvious question how in the world can a radar system report a pitot-static system remotely of an airplane dozens of miles away.

 

It doesn't of course read the MiG's actual CAS, it estimates it from known or assumed data often assuming that conditions at target are equal to those at ownship.

 

Radar itself measures relative velocities. Radar plus INS turns relative velocity into true motion of target. At this step it would be easy to display ground speed which is horizontal component of true motion.

 

But let's go further and estimate target TAS. TAS is just GS with winds. Does radar know wind at target locality? No, but it knows wind at ownship so it can estimate. If target is at a different altitude it can model the wind pattern up or down in height and make a guess. Perhaps there is some sheer layer and the real winds at target are totally different than assumption but usually it will be close enough. The result is target TAS.

 

But let's go further, turn estimate of target TAS into CAS. Use pressure and temperature model of atmosphere to estimate T&P at target location. Combine this with altimeter setting (or do all the work in pressure altitude) and you can make a reasonable estimate of CAS of a radar target.

 

I think it's no accident that if ED figure differs from real figure that ED's figure is the much easier one to calculate. Doing all the work to translate one velocity into an estimated airspeed is hard. Of course because it's software it can do what the real airplane can't and just pluck the target CAS from the target directly and perfectly. It's also easy to put the wrong figure on the display when you don't know why CAS was chosen as the displayed value.

 

Why would the pilot care about target CAS? What does target CAS mean in a combat situation? Why would a pilot not want TAS, GS, EAS, Mach, etc. instead?

[Dee-Jay]

In game behavior is different from RL.

Thus I said “ED or other reliable documents” and tagged “bug” this thread.

Don’t let me explain all.

 

1. Why ED use TAS number?

2. If implementation as mentioned above, what is source of implementation?

That’s all.

 

Okay I see what you mean now. Apologies for my misunderstanding.

Regards.

[Deano87]

So I’m guessing this is a bug then? As it’s showing TAS when it should be showing CAS, if I’m reading the OP correctly.