INS fix?

[amalahama]

Hi! I was the other day perusing the Apache Early Access flight manual and I was surprised as it seems that there is no option to manually apply INS fixes to the EGI. It's true that in a regular situation GPS will automatically update the INS drift so there won't be any need to perform manual INS fixes but other EGI equipped aircraft such as the A-10C, Hornet or Viper can still manually perform the operation if the pilot wishes so (and it might make sense in a GPS-denied area). So, does the real AH-64D have this functionality or it was discarded for whatever reason?

Edited November 8, 2022 by amalahama

[Swift.]

There is a mechanism to do this in the real Apache (think about the UPDT bit of the STORE/UPDT switch). I'm not sure if it's implemented yet.

[Raptor9]

The EGI behavior is still WIP, and the update procedure is not implemented at this time.

Having said that, the EGI in the AH-64D is highly automated so that it is rare the crew ever needs to interact with it.

[QuiGon]

3 hours ago, Raptor9 said:

Having said that, the EGI in the AH-64D is highly automated so that it is rare the crew ever needs to interact with it.

What if you fly a mission where there is no GPS available? You will have to rely on manual nav fixes in order to keep your INS from drifting away, don't you?

[Raptor9]

1 hour ago, QuiGon said:

What if you fly a mission where there is no GPS available? You will have to rely on manual nav fixes in order to keep your INS from drifting away, don't you?

Sure, but that would fall into the "what if" category. GPS has existed for the entirety of the AH-64D's existence. If you move the date to pre-GPS timeframe, you're simulating a time when AH-64Ds and EGIs themselves didn't even exist yet.

[amalahama]

Well, or a gps-denied environment which its actually a very much possible scenario in future conflicts.

 

Best regards

[Raptor9]

Just now, amalahama said:

Well, or a gps-denied environment which its actually a very much possible scenario in future conflicts.

Yes, of course...but again, this falls into the "what if" category. My statement of the EGI's being highly automated and rarely needing crew interaction was regarding their use in real-life.

[Britchot]

Crews practice using pilotage and maps in the event their GPS is jammed.

[QuiGon]

2 hours ago, Raptor9 said:

Yes, of course...but again, this falls into the "what if" category. My statement of the EGI's being highly automated and rarely needing crew interaction was regarding their use in real-life.

It's a realistic "what if" category though, as GPS denial is a possibility in a peer to peer conflict.
And apart from real world considerations, it's just a pain in the but to fly on servers where GPS is not available like BlueFlag Syria, and not being able to perform nav fixes.

Edited November 8, 2022 by QuiGon

[amalahama]

9 hours ago, QuiGon said:

It's a realistic "what if" category though, as GPS denial is a possibility in a peer to peer conflict.
And apart from real world considerations, it's just a pain in the but to fly on servers where GPS is not available like BlueFlag Syria, and not being able to perform nav fixes.

 

Well, I guess that the INS of those aircraft "magically" have no drift at all

[QuiGon]

1 hour ago, amalahama said:

Well, I guess that the INS of those aircraft "magically" have no drift at all

I haven't done a specific test on it, but I'm pretty sure the Apache INS does drift in missions without GPS and currently there is no way to fix the drift.

Edited November 9, 2022 by QuiGon

[Hobel]

vor 3 Stunden schrieb amalahama:

Well, I guess that the INS of those aircraft "magically" have no drift at all

in The Viggen and F16 there is in any case a drift when the GPS is off or not present and need a NavFix

I think this is also the case with other aircraft in DCS.

[amalahama]

6 minutes ago, Hobel said:

in The Viggen and F16 there is in any case a drift when the GPS is off or not present and need a NavFix

I think this is also the case with other aircraft in DCS.

At least Ka-50, A-10C and AV8B dont model drift at this stage.

Best regards

Edited November 9, 2022 by amalahama

[Raptor9]

It seems that you all are mixing a lot of different types of nav systems in here and expecting them all to behave the same. (And I mean that in a very generic sense)

Different nav systems experience different types of drift. For example, some aircraft that have been named here incorporate EGI (like the AH-64D or A-10C), others incorporate INS with various outside inputs (one of which may be GPS augmentation). There is a difference, depending on how each specific navigation system processes external inputs through various algorithms and filters, and which inputs are designed into that aircraft.

Having said that, I don't know which DCS aircraft have INS drift modeled vs not. But just because an aircraft INS doesn't drift in DCS doesn't mean that it isn't properly modeled.

[QuiGon]

19 hours ago, Raptor9 said:

It seems that you all are mixing a lot of different types of nav systems in here and expecting them all to behave the same. (And I mean that in a very generic sense)

Different nav systems experience different types of drift. For example, some aircraft that have been named here incorporate EGI (like the AH-64D or A-10C), others incorporate INS with various outside inputs (one of which may be GPS augmentation). There is a difference, depending on how each specific navigation system processes external inputs through various algorithms and filters, and which inputs are designed into that aircraft.

Having said that, I don't know which DCS aircraft have INS drift modeled vs not. But just because an aircraft INS doesn't drift in DCS doesn't mean that it isn't properly modeled.

I myself was talking about flying in missions where GPS is not available. In such a situation EGI (Embedded GPS INS) is nothing more than a pure INS, as the GPS part of it can't contribute anything. So even an Apache nav system should drift under such conditions, should it not?

Edited November 10, 2022 by QuiGon

[Swift.]

44 minutes ago, QuiGon said:

I myself was talking about flying in missions where GPS is not available. In such a situation EGI (Embedded GPS INS) is nothing more than a pure INS, as the GPS part of it can't contribute anything. So even an Apache nav system should drift under such conditions, should it not?

 

I would have thought the same. I know probably more about AH1Z than I do about apache, but on that helicopter its an RLG gyro in the EGI assembly, and it definitely mentions drifting of the INS when GPS data is not available.

[Raptor9]

5 hours ago, QuiGon said:

I myself was talking about flying in missions where GPS is not available.

I wasn't directing my previous statement at anything you said; I already replied that if you set the mission editor to a date prior to GPS existing, then yes, of course the GPS data would not be available.

However, the point is, that if people are expecting to perform alignments or occassional nav fixes in the DCS AH-64D after the EGI behavior is finalized, they shouldn't. As I originally stated, the system is automated so that crews rarely need to interact with it. They literally just verify it has finished aligning before taking off. No updating, no initiating an alignment; except for the occassional malfunction, which is rare but possible with anything in real life.

There were comparisons made to various other DCS aircraft, some of which do not have EGIs, which is what my previous statement was addressing. The topic of GPS jamming was also brought up, but seeing as how GPS jamming doesn't exist in DCS, that falls into the "what if" category as I also stated, just as the case of using an AH-64D at a date prior to GPS existing.

And before anyone tries to sharpshoot this statement. Yes, I am well aware of the possible future real-life scenarios in which adversaries could use GPS denial systems. However, I am not going to engage in discussions on how those types of scenarios will impact AH-64 functions or how they would be countered, because 1) such conversations fall into the sensitive topic category, and 2) it isn't relevant for DCS anyway.

[QuiGon]

4 hours ago, Raptor9 said:

 The topic of GPS jamming was also brought up, but seeing as how GPS jamming doesn't exist in DCS, that falls into the "what if" category as I also stated, just as the case of using an AH-64D at a date prior to GPS existing.

[...]

2) it isn't relevant for DCS anyway.

I don't understand how this is irrelevant for DCS as DCS has a built in function to disable GPS availability in a mission, so you can very well simulate GPS jamming in DCS.
But I also don't understand why we are discussing this, as the EGI (including the INS) is still WIP and once completed it will also include the ability to perform INS fixes in GPS denied missions, or not?

[Raptor9]

2 hours ago, QuiGon said:

I don't understand how this is irrelevant for DCS as DCS has a built in function to disable GPS availability in a mission, so you can very well simulate GPS jamming in DCS.

If you are referring to the "Unrestricted SATNAV" option, that simply allows GNSS-capable aircraft on the Red coalition to use the GPS satellite network. If this option is enforced as unavailable in a mission, and you put an AH-64D, F-16, or A-10 on the Red side, they will not have access to GPS signals. If you place an aircraft on Blue side, they'll always have GPS access unless you move the date to the early 1980's or prior (I don't remember the date threshold in DCS).

2 hours ago, QuiGon said:

But I also don't understand why we are discussing this, as the EGI (including the INS) is still WIP and once completed it will also include the ability to perform INS fixes in GPS denied missions, or not?

This is turning into a discussion on the discussion, and it needn't be. If you re-read what my initial comments were, all I stated in response to the OP was that when the EGI is fully implemented (if it is implemented to be accurate to real-life), the task of needing to update the AH-64D's EGI would not be necessary due to its automated and integrated nature; even though there is a procedure, you shouldn't need it or even get an option for it.

However, yes, if the mission editor date is set to a year prior to GPS existing, or the AH-64D's were given to the Red coalition and GPS was restricted from the Red coalition in the mission editor, then sure, you could say that there is a "GPS denied environment". I never said anything to the contrary; I was providing real-world context to the OP's question as to why there isn't an option in the AH-64D to perform INS position fixes by aircrew demand.

[QuiGon]

42 minutes ago, Raptor9 said:

If you are referring to the "Unrestricted SATNAV" option, that simply allows GNSS-capable aircraft on the Red coalition to use the GPS satellite network. If this option is enforced as unavailable in a mission, and you put an AH-64D, F-16, or A-10 on the Red side, they will not have access to GPS signals. If you place an aircraft on Blue side, they'll always have GPS access unless you move the date to the early 1980's or prior (I don't remember the date threshold in DCS).

Yes, this is what I meant and this is the case on some major public servers like BlueFlag Syria. If you fly the Apache on such GPS restricted missions, your INS will drift and you have no way to counter that atm.
So I hope the real Apache INS fix functions will get implemented into the DCS Apache eventually, so you can deal with such INS drift in such a GPS denied environment.
 

42 minutes ago, Raptor9 said:

This is turning into a discussion on the discussion, and it needn't be. If you re-read what my initial comments were, all I stated in response to the OP was that when the EGI is fully implemented (if it is implemented to be accurate to real-life), the task of needing to update the AH-64D's EGI would not be necessary due to its automated and integrated nature; even though there is a procedure, you shouldn't need it or even get an option for it.

However, yes, if the mission editor date is set to a year prior to GPS existing, or the AH-64D's were given to the Red coalition and GPS was restricted from the Red coalition in the mission editor, then sure, you could say that there is a "GPS denied environment". I never said anything to the contrary; I was providing real-world context to the OP's question as to why there isn't an option in the AH-64D to perform INS position fixes by aircrew demand.

Alright, but I don't think anyone here ever argued that manual nav fixes are needed if GPS is available. The OP himself was talking about INS handling in a GPS denied environment.

Edited November 10, 2022 by QuiGon

[Fromthedeep]

2 minutes ago, QuiGon said:

Alright, but I don't think anyone here ever argued that manual nav fixes are needed if GPS is available. The OP himself was talking about INS handling in a GPS denied environment.

Based on the previous input by Raptor it seems to me that the DCS Apache is not intended to be operated in a GPS denied environment in game. 

[QuiGon]

5 minutes ago, Fromthedeep said:

Based on the previous input by Raptor it seems to me that the DCS Apache is not intended to be operated in a GPS denied environment in game. 

Hmm, I have not seen such a statement in his comments. That would also be a rather odd design decision, especially since INS drift is already simulated for the Apache ingame IIRC. Just the fix options are missing.

Edited November 10, 2022 by QuiGon

[Fromthedeep]

3 minutes ago, QuiGon said:

Hmm, I have not identified such a statement in his comments. That would also be a rather odd design decision.

This quote seems to indicate that, but I could be misreading it.

7 hours ago, Raptor9 said:

However, the point is, that if people are expecting to perform alignments or occassional nav fixes in the DCS AH-64D after the EGI behavior is finalized, they shouldn't

[QuiGon]

Just now, Fromthedeep said:

This quote seems to indicate that, but I could be misreading it.

I think he was talking about situations where GPS is available.

[Raptor9]

16 minutes ago, QuiGon said:

Alright, but I don't think anyone here ever argued that manual nav fixes are needed if GPS is available. The OP himself was talking about INS handling in a GPS denied environment.

And to reiterate, this is what I said:

The underlined portions are what drove my very first reply in this thread about the automated nature of the EGI not including an option for the aircrew to do a fix whenever they want, and the reason it isn't in the manual is because it isn't implemented yet. This discussion is going far beyond the scope of what the intent was behind my first response. You guys are reading too much into what I am saying.