LS 6 And GB 6 are still stupid ?

[sylkhan]

On 2/7/2024 at 4:24 PM, Lord Vader said:

Hello all

After we reviewed the tracks and observed the conditions, we believe we have found the culprit for your reports.

It's actually a feature in DCS, regarding GPS quality.

In your track @RPY Variable your F-16C is set to the Red Coalition. As such, the GPS quality is by default much lower than the Blue Coalition. In order to mitigate this, you can select "unrestricted sat nav" option in the Mission Editor or just select a Blue coalition side. 

I tested this myself with the DCS: F-16C Viper and with the DCS: A-10C II Warthog and you can observe the difference. 

Without proper or with poor GPS guidance, the GBU-38 can have a CEP at about 30m or even more. So this is actually well modelled.

Thank you for your patience and, yes, this was a tricky one. 

I thought it was a joke, but it isn't.
That's crazy.....
I will select "unrestricted sat nav" option in the Mission Editor, and see the difference.

Edited March 6, 2024 by sylkhan

[okopanja]

4 minutes ago, sylkhan said:

I thought it was a joke, but it isn't.
It's crazy.....
I will select "unrestricted sat nav" option in the Mission Editor, and see the difference.

Once upon a time precision was limited for civilian use. Someone recently mentioned that speed limit is still being enforced. I am not deep into that topic, so do not consider it as accurate.

[sylkhan]

5 minutes ago, okopanja said:

Once upon a time precision was limited for civilian use. Someone recently mentioned that speed limit is still being enforced. I am not deep into that topic, so do not consider it as accurate.

It's a post from an ED team Guy

[okopanja]

16 minutes ago, sylkhan said:

It's a post from an ED team Guy

Link?

[jubuttib]

26 minutes ago, okopanja said:

Once upon a time precision was limited for civilian use. Someone recently mentioned that speed limit is still being enforced. I am not deep into that topic, so do not consider it as accurate.

It's also possible that it's trying to be a GPS vs. GLONASS thing.

[sylkhan]

15 minutes ago, okopanja said:

Link?

 

[sylkhan]

ok, i have done 2 tests on blue side, 4 ls6-250, 4/4 hits 2 times 100% hit.

I can confirm accuracy on blue side is Ok, the inaccuracy is on red side due to the stupid new feature (lol) of ED.
I would like to understand why a red JF-17 should have a worst GPS guidance, than a blue JF-17.

[Napillo]

2 hours ago, sylkhan said:

a red JF-17 should have a worst GPS guidance, than a blue JF-17.

Did you check the box for unrestricted sat nav?

[sylkhan]

56 minutes ago, Napillo said:

Did you check the box for unrestricted sat nav?

Yes i know, red side + "unrestricted sat nav" checked in the options has the same GPS accuracy than blue side, but i don't
understand why ED has degrade GPS accuracy for red side.

Edited March 6, 2024 by sylkhan

[okopanja]

14 minutes ago, sylkhan said:

Yes i know, red side + "unrestricted sat nav" checked in the options has the same GPS accuracy than blue side, but i don't
understand why ED has degrade GPS accuracy for red side.

 

I asked in other topic...

[supersylph]

2 hours ago, sylkhan said:

是的，我知道，选项中选中的红方+“不受限制的卫星导航”具有与蓝方相同的 GPS 精度，但我不明白
为什么 ED 会降低红方的 GPS 精度。

 

ED may be simulating that the blue side can use military GPS, while the red side uses civilian GPS, so there is an accuracy difference.

[okopanja]

Just now, supersylph said:

ED may be simulating that the blue side can use military GPS, while the red side uses civilian GPS, so there is an accuracy difference.

Can you tell us more what is the difference between blue/red JF-17?

[jubuttib]

5 hours ago, sylkhan said:

Yes i know, red side + "unrestricted sat nav" checked in the options has the same GPS accuracy than blue side, but i don't
understand why ED has degrade GPS accuracy for red side.

 

From what I can find online, GPS has marginally better accuracy than GLONASS (the Russian equivalent of GPS), and European GALILEO is supposedly even better, and in a war situation they'd probably try to interfere with Russian's ability to use American GPS satellites.

I'm guessing that's the reasoning. Though AFAIK BeiDou, the Chinese system, is probably the best and most dense currently.

[sylkhan]

On 3/7/2024 at 12:25 AM, supersylph said:

ED may be simulating that the blue side can use military GPS, while the red side uses civilian GPS, so there is an accuracy difference.

Yes, it is the new system from ED, but they forgot (strangely) to add red ECM, that gives the "blue" military GPS system,  lower accuracy or
no accuracy at all)
For the red side and to get around this, DEKA should do an optional ("what if" FC1 version like ED have done with KA-50) with 2 minor changes
1- "BEIDOU" guidance system (i don't thinks it's modelled in DCS, unfortunately, but we can use glonass with better accuracy )
2- Metric system
There is already a chinese mod cockpit.
Problem solved.

Edited March 12, 2024 by sylkhan

[Napillo]

re: GPS - the selective availability was disabled in 2000, giving civilians access to the same GPS signals as military, though military uses DGPS and / or WAAS. Accuracy is around 7.5 meters for GPS only, though you can and a lot of the time do get better accuracy on your phone GPS because it uses AGPS along with other methods. GLONASS is more accurate around the northernmost latitudes, due to orbit differences between the satellites, though that would be about 60 degrees latitude and above, which would only seem to be in places that aren't currently part of the DCS map set.

[jubuttib]

On 3/13/2024 at 5:56 PM, Napillo said:

re: GPS - the selective availability was disabled in 2000, giving civilians access to the same GPS signals as military, though military uses DGPS and / or WAAS. Accuracy is around 7.5 meters for GPS only, though you can and a lot of the time do get better accuracy on your phone GPS because it uses AGPS along with other methods. GLONASS is more accurate around the northernmost latitudes, due to orbit differences between the satellites, though that would be about 60 degrees latitude and above, which would only seem to be in places that aren't currently part of the DCS map set.

Good stuff. To add, from what I've read Beidou by comparison seems to provide the highest accuracy in "developing nations and 3rd world countries".

[qacarxan]

Long post but bear with me. If a mission is set in the past few years, there's no justification for ED to downgrade red more than blue based on everything I've read. For context, my work involves extensive use of remote sensing and GPS in remote regions, though I am not involved in the design or deployment of positioning systems, or any military application of these technologies (I do agricultural and ecological research). At any rate, to the sources:

"In the present study, the Signal-in-space range error (SISRE) computation method for different types of navigation satellites was presented. The differential code bias (DCB) correction method for BDS-3 new signals was deduced. Based on these, analysis and evaluation were done by adopting the actual measured data after the official launching of BDS-3. The results showed that BDS-3 performed better than the regional navigation satellite system (BDS-2) in terms of SISRE. Specifically, the SISRE of the BDS-3 medium earth orbit (MEO) satellites reached 0.52 m, slightly inferior compared to 0.4 m from Galileo, marginally better than 0.59 m from GPS, and significantly better than 2.33 m from GLONASS." (emphasis mine)

Source: https://www.nature.com/articles/s41598-022-12012-y

"Pakistan also signed a first-of-its-kind agreement with China in 2013 to install five BeiDou ground augmentation stations and one processing center, allowing greater accuracy in the country." Note: That's mostly just relevant to our own module and the Persian Gulf map. But there's more on a global scale:

"When solely relying on a real-time fix from orbiting satellites, all four GNSS [i.e. GPS, Glonass, Beidou, Galileo] have roughly comparable performance, given that GLONASS is closing the performance gap."

Source for both: https://ndupress.ndu.edu/Media/News/News-Article-View/Article/2999161/beidou-chinas-gps-challenger-takes-its-place-on-the-world-stage/

"General Holmes, who leads the Air Force's Air Combat Command (ACC), was responding to a question about military communications system vulnerabilities at a conference in Washington, DC. And he opined that the Air Force should be able to use the wide variety of commercial communications paths available.
'My U-2 guys fly with a watch now that ties into GPS but also BeiDou and the Russian system and European system... so if someone jams GPS they still get the others,' Holmes said."

Note: the article goes on to explain that General Holmes did not get his facts straight and the watch compares only GPS and Glonass, but it brings up a wider point; namely, the use of multiple GNSS in degraded situations. Chinese geoscientists have also done extensive research on hybrid systems and their accuracy, so this idea of combining and comparing is not news to them either. 

Source: https://arstechnica.com/gadgets/2020/03/why-are-u-2-jet-pilots-wearing-garmin-satellite-navigation-smartwatches/

Bringing it back to the JF-17, the Minhasians conducted a cross-border strike into Iran in January. Some news agencies claimed they used a glide bomb similar to the in-game LS-6 but with a rocket range extender and the imprecise CEP of "less than 20m" with GPS and INS guidance. The targets--a Baluch separatist group--confirmed their people were hit (and unfortunately many reports confirmed civilian deaths as well). There are conflicting reports as to the distance from which the weapons were deployed. I haven' seen any confirmation from the Pakistani government as to the weapons used; just a confirmation from the official JF-17 website that the Minhasians were part of the strike. If the bomb is indeed GPS-guided, that could be an argument for degraded accuracy if flying against bluefor, but if they meant GNSS-guided with Beidou and just said GPS the way Americans say "kleenex" for all tissues, then we're back to the point about Beidou. But again, in this instance, whatever munitions they used hit the target, per their own enemies' public statements.

Sources: https://newsguru.pk/pakistans-iran-strike-unveiling-the-weaponry-details/

https://jf-17.com/2024/01/18/jf-17-fighter-jets-take-charge-in-swift-response-launching-powerful-strikes-against-terrorists-inside-iran/

At any rate, based on research showing accuracy of the latest generation of Beidou equivalent to or slightly better than US GPS, as well as statements from US personnel and defense analysts above, I'm not sure what justification there can be for a biased GNSS default in DCS for any mission set in the past few years. Older than that, fair enough, but not since 3rd gen Beidou came out. Glonass is improving too, according to the NDU. 

[jubuttib]

Ooh, good stuff, thanks!

FWIW I would expect that if they're indeed trying to simulate a capability discrepancy and not blufor jamming or something like that, they'd be doing it with the assumption of RED = Russia, so using GLONASS, and wouldn't currently be able to separate the JF-17, which would more likely be capable of using Beidou, into its own bucket. I.e. I think it's a redfor/blufor thing, not a per plane type/nation thing.

Heck, when I tested the accuracy between red and blue, the JF-17 on the red side was a USAF Aggressor one, i.e. a US plane...

[qacarxan]

On 3/18/2024 at 5:27 PM, jubuttib said:

Ooh, good stuff, thanks!

FWIW I would expect that if they're indeed trying to simulate a capability discrepancy and not blufor jamming or something like that, they'd be doing it with the assumption of RED = Russia, so using GLONASS, and wouldn't currently be able to separate the JF-17, which would more likely be capable of using Beidou, into its own bucket. I.e. I think it's a redfor/blufor thing, not a per plane type/nation thing.

Heck, when I tested the accuracy between red and blue, the JF-17 on the red side was a USAF Aggressor one, i.e. a US plane...

My pleasure!

Regarding accuracy based solely on GLONASS, what I shared above also addressed the relative precision of GLONASS itself and not just a jamming scenario. To whit:

"When solely relying on a real-time fix from orbiting satellites, all four GNSS [i.e. GPS, Glonass, Beidou, Galileo] have roughly comparable performance, given that GLONASS is closing the performance gap."

Source: https://ndupress.ndu.edu/Media/News/News-Article-View/Article/2999161/beidou-chinas-gps-challenger-takes-its-place-on-the-world-stage/

So there's still no justification for unilateral GNSS degradation for contemporary mission settings. The difference is a SISRE of 0.6m for GPS vs 2.3m for GLONASS. If they want to really get petty about it, they could make redfor munitions 1.7m less precise, on average. That's still minute-of-tank for my gameplay purposes!

[jubuttib]

Have a like for "minute-of-tank", though I guess "tank-of-angle" would be more accurate, hehe.