Foe ED: Loosely Coupled navigation

[LastRifleRound]

Is this going to be implemented for the Hornet? I.e., when in NAV instead of IFA, will we see drift? Will the various navigation correction options be implemented such as desg, tacan, gps and map?

 

I ask because past ED modules don't simulate this. The only modules simulating this are Viggen and Tomcat. M2000 simulated drift but the correction methods aren't implemented properly.

 

To be clear, I am not asking for a timeline. I just want to know if this is planned to be implemented for the module to be considered feature complete. I appreciate your time and interaction with the community. :thumbup:

[LastRifleRound]

Should a fully functional INS really be considered a "wish"? I'm not making a request, I'm asking if this is intended to be implemented.

[Weta43]

Actually, past E.D. modules did simulate this.

Then they stopped...

[Kev2go]

Its true, drift isn't currently modeled nor IFA, but eventually once navigation is complete , any drifts probably wont be noticeable.

 

In NAv mode currently you have INS and GPS modes, which can be seen in respective options via HSI, IE POS/INS, POS/GPS ( GPS will eventually its own dedicated page outside of HSI) . However even though its not an EGI, the INS+GPS system are still linked, and as long as GPS works or has signal to the satellite it should correct any INS drifts, making the INS remain accurate as long as there is no GPS signal interruption or jamming. Latter case is not simulated.

 

There should eventually also be an AINS mode (POS/AINS) which essentially is something equivalent of a "blended" solution terminology used in aircraft with EGI. At least once ED fully finishes the navigation concept of the F/A18.

Edited February 27, 2020 by Kev2go

[LastRifleRound]

IFA is just in flight alignment mode. once aligned in flight, a pilot can switch back to NAV.

 

In NAv mode currently you have INS and GPS modes, which can be seen in respective options via HSI, IE POS/INS, POS/GPS ( GPS will eventually its own dedicated page outside of HSI) . However even though its not an EGI, the INS+GPS system are still linked, and as long as GPS works or has signal to the satellite it should correct any INS drifts, making the INS remain accurate as long as there is no GPS signal interruption or jamming. Latter case is not simulated.

 

There should eventually also be an AINS mode (POS/AINS) which essentially is something equivalent of a "blended" solution terminology used in aircraft with EGI.

 

Is this sourced from the NATOPS? I know in the Harrier NAV is loosely coupled, meaning automatic inflight alignments will not be performed with GPS even if available. That is why there is a GPS option under UPD on the EHSD.

 

I also know that the procedure according to real Hornet pilots is to have the knob turned to IFA all the time, not NAV. Not sure why this would be their procedure if it was strictly only for one-time alignment. I will read the NATOPS for the FA18. I assumed it was the same because all the options for the UPDT are already on the Hornet HSI in DCS, they just don't do anything yet, and are just like the Harrier.

[Harker]

I was also under the impression that IFA is the correct one to select; ever since the INS/GPS system was implemented in the Harrier, you're supposed to select IFA after alignment is complete.

[Kev2go]

Is this sourced from the NATOPS? I know in the Harrier NAV is loosely coupled, meaning automatic inflight alignments will not be performed with GPS even if available. That is why there is a GPS option under UPD on the EHSD.

 

I also know that the procedure according to real Hornet pilots is to have the knob turned to IFA all the time, not NAV. Not sure why this would be their procedure if it was strictly only for one-time alignment. I will read the NATOPS for the FA18. I assumed it was the same because all the options for the UPDT are already on the Hornet HSI in DCS, they just don't do anything yet, and are just like the Harrier.

 

to quote :

 

 

 

" In AINS mode INS and GPS are mutually aiding each other to provide an optimal navigation solution"

 

 

"in AINS the horizontal position is updated every 40 seconds, and velocities every 5 seconds"

 

 

So yes GPS is able to correct/update the INS within intervals, the only noted difference in performance is that for hornets with EGI are able to update the INS much more frequently every 4 seconds for horizontal and vertical positions.

Edited February 27, 2020 by Kev2go

[LastRifleRound]

to quote :

 

 

 

" In AINS mode INS and GPS are mutually aiding each other to provide an optimal navigation solution"

 

 

"in AINS the horizontal position is updated every 40 seconds, and velocities every 5 seconds"

 

 

So yes GPS is able to correct/update the INS within intervals, the only noted difference in performance is that for hornets with EGI are able to update the INS much more frequently every 4 seconds for horizontal and vertical positions.

 

AINS is only active if the switch is in the IFA position othwerise "loosely coupled" INS navigation is used. From VII-24-6, 24.1.6.1:

 

"24.1.6.1 INS Mode Select Knob. The INS mode select knob has switch positions of OFF, CV, GND,NAV, IFA, GYRO, GB, and TEST. Selecting OFF removes power from the INS. Selecting CV

commands the INS carrier align mode with the MC providing the carrier align display. Selecting GND commands the INS ground align mode with the MC providing the ground align display. Selecting NAV commands the INS navigation mode which enables the MC to use INS information to provide navigation steering. Selecting IFA without GPS, commands the INS IFA (Inflight Alignment) mode with an IFA display. Selecting IFA with GPS, commands the Aided INS (AINS) position keeping or GPS inflight alignment with an IFA display. Selecting GYRO commands the AHRS (Attitude Heading Reference Set) mode. Selecting GB commands the gyro bias mode enabling the INS to do a gyro bias calibration. Selecting TEST enables the INS to perform an initiated BIT upon command from the MC."

[Kev2go]

AINS is only active if the switch is in the IFA position othwerise "loosely coupled" INS navigation is used. From VII-24-6, 24.1.6.1:

 

"24.1.6.1 INS Mode Select Knob. The INS mode select knob has switch positions of OFF, CV, GND,NAV, IFA, GYRO, GB, and TEST. Selecting OFF removes power from the INS. Selecting CV

commands the INS carrier align mode with the MC providing the carrier align display. Selecting GND commands the INS ground align mode with the MC providing the ground align display. Selecting NAV commands the INS navigation mode which enables the MC to use INS information to provide navigation steering. Selecting IFA without GPS, commands the INS IFA (Inflight Alignment) mode with an IFA display. Selecting IFA with GPS, commands the Aided INS (AINS) position keeping or GPS inflight alignment with an IFA display. Selecting GYRO commands the AHRS (Attitude Heading Reference Set) mode. Selecting GB commands the gyro bias mode enabling the INS to do a gyro bias calibration. Selecting TEST enables the INS to perform an initiated BIT upon command from the MC."

 

and? that still means INS is updated by the GPS. i dont see your point in why anything other than that would be used unless malfunction or loss of GPS signal? I think were are going in circles now.

 

We all realize Hornet is in EA, so you can't expect entire navigation suite to work as its supposed to. It doesnt make sense for ED to force INS drift now at this current point in time for an EA product as that would make already added GPS weapons redundant, without proper integration of the GPS aspect, or current lack of AINS mode.

Edited February 28, 2020 by Kev2go

[LastRifleRound]

and? that still means INS is updated by the GPS. i dont see your point in why anything other than that would be used unless malfunction or loss of GPS signal? I think were are going in circles now.

 

We all realize Hornet is in EA, so you can't expect entire navigation suite to work as its supposed to. It doesnt make sense for ED to force INS drift now at this current point in time for an EA product as that would make already added GPS weapons redundant, without proper integration of the GPS aspect, or current lack of AINS mode.

 

I'm confused by this response.

 

First of all, if the knob is in NAV, the INS is NOT updated by the GPS. You just said AINS updates the INS. I posted proof that AINS is not active if the knob is in NAV and so what AINS does is irrelevant. Are you saying any of this is wrong? You don't address it in your response. It came from the same document you cited, just several pages after.

 

For the second part of your response, did you read my original post at all? It says "Do you plan on" and "I'm not asking for a timeline", so again, you seem to be making paper tigers here. I'm not asking anyone to prioritize anything. Just want to know if they're going to do it eventually, since none of their modules simulate drift, it's a legitimate question.

[Kev2go]

I'm confused by this response.

 

First of all, if the knob is in NAV, the INS is NOT updated by the GPS. You just said AINS updates the INS. I posted proof that AINS is not active if the knob is in NAV and so what AINS does is irrelevant. Are you saying any of this is wrong? You don't address it in your response. It came from the same document you cited, just several pages after.

 

For the second part of your response, did you read my original post at all? It says "Do you plan on" and "I'm not asking for a timeline", so again, you seem to be making paper tigers here. I'm not asking anyone to prioritize anything. Just want to know if they're going to do it eventually, since none of their modules simulate drift, it's a legitimate question.

 

and? im confused by your response. I knew that already, as i was already citing natops. All i pointed out was the GPS does update the INS, not sidestepping the discussion into which mode it needs to be operated in to do so, when considering the only reason we dont get INS drift in NAV when operating purely on INS system alone is because its not simulated with an incomplete navigation system. Switching to IFA right now changes nothing.

 

The IFA on the navigation panel still exists in EGI equipped hornets, and isn't just for the INS+GPS loosely coupled system for the type of hornet we have in DCS.

 

Furthermore I know your original question is asking if its planned, But it think its self explanatory question. IF it had such a feature, and functions in such a way then its a feature that should be expected to be added. I would like to think its only a matter of when as opposed to a matter of if.

But i suppose what you are looking for is a clarification and/or reassurance from someone from ED if it will be implemented yes?

Edited February 28, 2020 by Kev2go

[LastRifleRound]

I am, because again, this is supposed to be a feature of the KA50 and A10 and it is NOT modeled there. So it is ambiguous as to whether this will be modeled in the hornet. They say "fully featured" but I don't know what that means, as it seems to vary from module to module and system to system.

 

Search INU update for KA50 on these forums and you'll find hundreds of threads from people surprised and disappointed that INU update does nothing. I'm just trying to avoid that situation here.

[Hippo]

From the NATOPS:

 

24.2 INERTIAL NAVIGATION SYSTEM (INS)/GLOBAL POSITIONING SYSTEM (GPS)

 

The AN/ASN-130A (aircraft 161353 THRU 163175 BEFORE AFC 231, 231 PT2, or 231 PT3),

 

the AN/ASN-139 (aircraft 163427 THRU 164912 BEFORE AFC 175 PT2),

 

the Embedded GPS/INS (EGI) (aircraft 161925 THRU 163175 AFTER AFC 231, 231 PT2, or 231 PT3),

 

or the INS + GPS (aircraft 164945 AND UP, 163427 THRU 164912 AFTER AFC 175 PT2) inertial navigation system is a self-contained, fully automatic dead reckoning navigation system.

 

From this (and I remain quite confused) I deduce that:

 

 

1. the INS + GPS is what should be in the DCS F-18 (going by aircraft number)?

 

2. this (INS + GPS) system is more advanced that EGI (because it appears in later aircraft)?

 

Can someone explain in layman's terms what the difference is between these two / four systems described above?

 

Has ED ever confirmed which is being simulated in the DCS F-18?

 

Just from going through chapter 24, it seems like a lot of work remains to be done. Has ED ever stated how closely the simulation will match what's in the NATOPS (AIMS, etc).?

Edited February 28, 2020 by Hippo

[Kev2go]

I am, because again, this is supposed to be a feature of the KA50 and A10 and it is NOT modeled there. So it is ambiguous as to whether this will be modeled in the hornet. They say "fully featured" but I don't know what that means, as it seems to vary from module to module and system to system.

 

Search INU update for KA50 on these forums and you'll find hundreds of threads from people surprised and disappointed that INU update does nothing. I'm just trying to avoid that situation here.

 

ah ok then fair enough. Sorry for misunderstanding you.

[Kev2go]

From the NATOPS:

 

From this I deduce that:

 

 

1. the INS + GPS is what should be in the DCS F-18 (going by aircraft number)

 

2. this (INS + GPS) system is more advanced that EGI (because it appears in later aircraft)?

 

Can someone explain in layman's terms what the difference is between these two / four systems described above?

 

Has ED ever confirmed which is being simulated in the DCS F-18?

 

Just from going through chapter 24, it seems like a lot of work remains to be done. Has ED ever stated how closely the simulation will match what's in the NATOPS (AIMS, etc).?

 

 

my overly basic understanding is the EGI systems are just 1 closely directly integrated module ( all INS/GPS all on one box) as opposed to two separate systems. A INS and separate add on GPS module linked to each other when at the end of the day both aim to accomplish the same goal.

 

My theory is the reason why you initially had aircraft with INS+GPS it was deemed a faster and cheaper solution to just add on a GPS system to an already present INS system in a legacy platform as long as there was available space to place said avionics and wire them together as opposed to developing a new but integrated all one navigation module that takes up less space.

 

Although judging from natops EGI is in fact superior in performance as well, since in the manual its claimed both vertical and horizontal position can be updated in intervals of 4 seconds as opposed to 40 seconds for horizontal position, and 5 seconds for vertical for INS+ GPS system. IM guessing being integrated EGI is less prone to error, and also updates position in near real time, but INS+GPS system seems just good enough, as there probably wouldn't be any noticeable INS drift in 36 seconds longer it takes for a update. Although i imagine for absolute precision of GPS guided munitions, the more accurate the system the better.

 

 

I theorize the reasoning why older hornets got priority to get EGI as opposed to newer lots, i think it was because they had an even older INS system. Initially Hornets had AN/ASN130A wheras newer lots ( even prior to GPS) got AN/ASN139 system which was a laser ring Gyro based INS system as opposed to a purely mechanical one.

 

 

There are public sources that describes the various integrations of navigation systems.

 

 

https://apps.dtic.mil/dtic/tr/fulltext/u2/a581020.pdf

Edited February 28, 2020 by Kev2go

[Robin_Hood]

What is your source for the INS being automatically updated by GPS when not in AINS ? Because that's not what the NATOPS seems to say (eg. in the phrase "In GPS capable aircraft the INS is

coupled to the GPS (in AINS mode) to provide a more accurate aided source of position and velocity").

 

Also, remember that GPS can be disabled in DCS (by date or by coalition), so that makes it relevant.

Edited March 2, 2020 by Robin_Hood

[LastRifleRound]

What is your source for the INS being automatically updated by GPS when not in AINS ? Because that's not what the NATOPS seems to say (eg. in the phrase "In GPS capable aircraft the INS is

coupled to the GPS (in AINS mode) to provide a more accurate aided source of position and velocity").

 

Also, remember that GPS can be disabled in DCS (by date or by coalition), so that makes it relevant.

 

My point exactly