Curious what does HSI UPDT do?

[ruddy122]

Was looking at the Navigation Page what does UPDT do in the module?

 

In the B-1B we used to refine the Navigation solution via Offset Aim Points

 

Similar Concept or the GPS beats the NAV Solution to submission

 

I think the viper and Eagle do that does the Hornet do that too?

 

 

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[ruddy122]

Sorry in other words the GPS updates the navigation solution and there is no need to update


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[Pieterras]

The UPDT option is located along the top row of the HSI display and when
selected provides the UPDT sublevel display. This sublevel display allows the selection of VEL
(velocity), TCN, GPS, DSG (designation), AUTO, or MAP as the update source. Following the
selection of one of the update options, an ACPT/REJ (accept/reject) display is presented in which the
update can either be accepted or rejected. After selection of ACPT or REJ the top level HSI display
is returned. There is no ACPT/REJ display presented when the AUTO option is selected. Velocity
update is described in NTRP 3-22.4-FA18A-D and NTRP 3-22.2-FA18A-D NATIP. For F/A-18C/D,
if a previous update has been accepted, a CANCEL option is also displayed on the UPDT sublevel
which allows the aircrew to cancel the last accepted update.

[ruddy122]

Cool so you can update or reject the update you selected

Back in the early two thousands the GPS over rides the Kalman Filter automatically telling the B-1 where it is and refining the navigation solution

The viper and the Eagle have something similar starts with an e basically the ins is helped with the GPS for optimum navigation solution


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[Harker]

Our Hornet also has INS aided by GPS, called AINS. I imagine that these INS update options are used when GPS is completely unavailable or n only on-secure GPS connection is available and the NOSEC option is not desired.

[Michael Ault]

There is no ACPT/REJ display presented when the AUTO option is selected. Velocity update is described in NTRP 3-22.4-FA18A-D and NTRP 3-22.2-FA18A-D NATIP. gimp 2.8 download

Edited May 13, 2021 by Michael Ault

[amalahama]

Is this modeled in DCS?

[Tholozor]

It's partially modeled. You can use the UPDT function to fix nav drift in a non-AINS mode via a TACAN or waypoint fix (like in the Tomcat). You can even change the position-keeping mode; so instead of POS/AINS or POS/INS, you can change it to POS/TCN (assuming the tuned station position is present in the MC). It won't be as accurate, but it's a decent backup.

Edited May 13, 2021 by Tholozor

[AvroLanc]

2 hours ago, Tholozor said:

It's partially modeled. You can use the UPDT function to fix nav drift in a non-AINS mode via a TACAN or waypoint fix (like in the Tomcat). You can even change the position-keeping mode; so instead of POS/AINS or POS/INS, you can change it to POS/TCN (assuming the tuned station position is present in the MC). It won't be as accurate, but it's a decent backup.

 

 

Yeah but none of this actually does anything, does it? It's just button pressing, there's no underlying simulation of INS drift or of all the different position keeping modes. If there is, it's certainly never been showcased or documented anywhere. 

[Harker]

You can experience both positional drift and attitude drift, without AINS. It's overmodeled though. The drift is way too much and the attitude accuracy loss is insane, at times, which makes no sense (GPS isn't used for attitude). It's like the source is the standby attitude indicator or something and it's nothing like what other, non-GPS aircraft experience.

[dorianR666]

16 hours ago, AvroLanc said:

Yeah but none of this actually does anything, does it?

it is implemented but its quite buggy.

causes lots of trouble in pre-gps missions.

[AvroLanc]

15 hours ago, Harker said:

You can experience both positional drift and attitude drift, without AINS. It's overmodeled though. The drift is way too much and the attitude accuracy loss is insane, at times, which makes no sense (GPS isn't used for attitude). It's like the source is the standby attitude indicator or something and it's nothing like what other, non-GPS aircraft experience.

 

18 minutes ago, dorianR666 said:

it is implemented but its quite buggy.

causes lots of trouble in pre-gps missions.

OK, I didn’t realise that a buggy drift feature was in. But that’s kinda my point, in my mind it’s not implemented if it’s that badly done. 
There’s not much point in having an INS drift model simulated if it’s done badly. Otherwise what’s the point of interacting with it?
Either you’ve got a GPS quality, no drift situation - which is perfectly authentic 99% of the time for a 2005 Hornet - or you’ve got a reasonable INS simulation that requires authentic update procedures, possible NAV uncertainty and maybe radar offset bombing etc. I’d like the option of the latter, but have no wish for a poor halfway house. 

Edited May 14, 2021 by AvroLanc

[amalahama]

Third parties (e.g. Heatblur) have developed in some cases quite complex INS drift simulations. I would expect nothing less from ED.

 

 

[BIGNEWY]

 

3 hours ago, dorianR666 said:

it is implemented but its quite buggy.

causes lots of trouble in pre-gps missions.

 

if you think there is a bug, or you have proof there is a problem make a report. 

 

Blanket statements saying its "buggy" dont help. 

 

thanks

[AvroLanc]

4 hours ago, BIGNEWY said:

 

 

if you think there is a bug, or you have proof there is a problem make a report. 

 

Blanket statements saying its "buggy" dont help. 

 

thanks

 

The problem is that we're not sure how it's intended to be implemented. This feature hasn't been documented or showcased in any way by ED. Are we looking for and expecting a nice full rich simulation of the INS and it's associated update methods? If so, then sure bug reports could be made. If not, then we don't know what's 'buggy' and what's merely wishlist....

 

Thanks.

[Hulkbust44]

On 5/13/2021 at 12:34 PM, Harker said:

You can experience both positional drift and attitude drift, without AINS. It's overmodeled though. The drift is way too much and the attitude accuracy loss is insane, at times, which makes no sense (GPS isn't used for attitude). It's like the source is the standby attitude indicator or something and it's nothing like what other, non-GPS aircraft experience.

Have we tried it when making sure that the ADI source is INS and not STBY? I mean it shouldn't work that way, but that's what came to mind.