Switch SD-10 to new scheme API used by AIM-120C

[GGTharos]

A higher beamwidth gets you a lot less power ... not that this is physically reasonable anyway, the beamwidth is driven by the antenna.   As for the R-77 seeker, I believe that it depends on the exact SD-10 variant.

[ShadowFrost]

R-77 is on an older scheme so CCM comparisons may not be useful. 

[Wyvern]

Iirc, only the very early few batches had R-77 seekers

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[okopanja]

I had some chance to use the PL-12 (fired from J-11A) on a GS server against human players.

• range is truly great when fired from high performance platform at high speed and altitude, in fact the platform limits the missile due to radar lock range. Effective against non-maneuvering targets (often hits medium-high target at 80-90km with mach 2.0 - 3.0, but when it comes to maneuvering targets it looks much worse then AMRAAM: too much energy loss + seeker seems to loose track too easily. Experienced players will not find issues to shake it off.
• HOJ does not work properly, look looks like missile follows pure pursuit. I will test this more in details in controlled environment and report.

In general it led to a more differentiated play, where the other part could not just sling AMRAAM and continue pushing. Certainly bad for newbies, but I trust more skilled will actually appreciate this.

Edited June 27, 2023 by okopanja

[Wyvern]

Have you tried this with the old scheme? (SD-10)

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[okopanja]

4 hours ago, Wyvern said:

Have you tried this with the old scheme? (SD-10)

Only vs AI, which did not show too many differences, since F-16 AI pushes forward and relies on notching. However I do believe that SD-10 is better than PL-12 atm, and that AMRAAM in fact is much more reliable the PL-12 (SD-10 on AMRAAM scheme). Pl-12 sometimes wildly change the orientation in terminal phase, similar to what was observed with AMRAAM and manual ECM blinking. In addition it can rotate for no particular reason the orientation of whole missile, at least in tacview from server. When fired on hot target that turns cold&low and does not maneuver, it rapidly looses the speed (e.g. from Mach 3 to 1).

Again these are mere observations, it would need to be reproduced under more controlled conditions.

[Napillo]

13 hours ago, okopanja said:

seeker seems to loose track too easily.

The diameter of the AIM-120 (hence its radar sensor maximum area) is 7 inches. That equals about a 38.5 square inches sensor. The SD-10 / PL-12 on the other hand, diameter is 7.9 inches, which equals around 49 square inches.  Theoretically, that gives the SD-10 / PL-12 about 27% more sensitivity than an AIM-120, and that's assuming the same radar emitter power.

[Pede]

On 6/27/2023 at 3:40 PM, Napillo said:

The diameter of the AIM-120 (hence its radar sensor maximum area) is 7 inches. That equals about a 38.5 square inches sensor. The SD-10 / PL-12 on the other hand, diameter is 7.9 inches, which equals around 49 square inches.  Theoretically, that gives the SD-10 / PL-12 about 27% more sensitivity than an AIM-120, and that's assuming the same radar emitter power.

There's a lot more to it than that though. It would be a mistake to assume that the SD10 and Aim120c5 have identical signal processing and power in their arrays. Potentially the SD10 could be more sensitive, but without very specific information we can only speculate. 

[Napillo]

On 6/30/2023 at 12:53 PM, Pede said:

It would be a mistake to assume that the SD10 and Aim120c5 have identical signal processing and power in their arrays.

Yea, the SD10 is only 9 years newer, so of course technology hasn't changed much in 9 years between 1996 and 2005, no nothing at all changed in that time. There's no way the SD-10 could have more advanced processors and power supplies, and antenna designs..

[Pede]

2 hours ago, Napillo said:

Yea, the SD10 is only 9 years newer, so of course technology hasn't changed much in 9 years between 1996 and 2005, no nothing at all changed in that time. There's no way the SD-10 could have more advanced processors and power supplies, and antenna designs.

It definitely could, but without actually knowing exactly what is inside the missile we're just speculating. Saying it's newer is meaningless because it wasn't designed by the same people, or even the same country. They could've identified design flaws present in other fox 3 missiles and gone an entirely different direction, or since it is China's first indigenous fox 3, made their own design flaws. Missiles are complex systems and without knowing their exact design and the designs of the systems within, it's just speculation. 

[Napillo]

18 hours ago, Pede said:

it's just speculation.

It's not though, the fact is, a larger antenna can pick up weaker signals - that's a fact. 

[Pede]

2 hours ago, Napillo said:

It's not though, the fact is, a larger antenna can pick up weaker signals - that's a fact. 

Can being operative word. There are a plethora of different antenna designs. The types of antennas on early aircraft radars are very very different from ones today even within the same type of radars. For instance the F14 and JF17 both have mechnaically scanned arrays, but if you so much as glance at them you'll see they are very different in design which led to very different capabilities in range and fidelity. Also that entirely disregards singal processing. For instance imagine that the aim120C-5 and SD10 are almost identical in design, the SD10 would have a larger array but if it was worse at processing incoming signals it could be worse or equal to the aim120-c when it comes to fidelity. These are just a few examples, we could create "what if" scenarios infinitely. For a more in depth explanation of why bigger doesn't necessarily equal better, MIT has a 6 hour lecture on YouTube on radar that you may find helpful. 

[Gungho]

Is the sd10 no good anymore? Slow hornet is dodging it head on with 8g turns. 

 

Edited July 5, 2023 by Gungho

[okopanja]

3 hours ago, Pede said:

Can being operative word. There are a plethora of different antenna designs. The types of antennas on early aircraft radars are very very different from ones today even within the same type of radars. For instance the F14 and JF17 both have mechnaically scanned arrays, but if you so much as glance at them you'll see they are very different in design which led to very different capabilities in range and fidelity. Also that entirely disregards singal processing. For instance imagine that the aim120C-5 and SD10 are almost identical in design, the SD10 would have a larger array but if it was worse at processing incoming signals it could be worse or equal to the aim120-c when it comes to fidelity. These are just a few examples, we could create "what if" scenarios infinitely. For a more in depth explanation of why bigger doesn't necessarily equal better, MIT has a 6 hour lecture on YouTube on radar that you may find helpful. 

In radar equation two most significant parameters are gain and wavelength (represented by square values, compared to transmissions Power, received Power and radar cross section of the target).

As we know, Gain itself is proportional to aperture of the antenna.

Obviously the radius of the antenna plays a large role in determining the maximal range of radar.

Since my radar knowledge is a bit rusty, and I may have missed on new antenna designs, could you please elaborate which antenna designs would allow me to have a larger effective area of antenna in smaller physical volume?

 

Edited July 5, 2023 by okopanja

[Pede]

9 hours ago, okopanja said:

In radar equation two most significant parameters are gain and wavelength (represented by square values, compared to transmissions Power, received Power and radar cross section of the target).

As we know, Gain itself is proportional to aperture of the antenna.

Obviously the radius of the antenna plays a large role in determining the maximal range of radar.

Since my radar knowledge is a bit rusty, and I may have missed on new antenna designs, could you please elaborate which antenna designs would allow me to have a larger effective area of antenna in smaller physical volume?

 

 

Since we're being cheeky, technically a phased array has a larger effective area of antenna than a planar array because the elements are more densely packed together due to the usage of phase shifters but I'm guessing you didn't know that. 

I'm guessing you probably also didn't know that modern planar arrays actually feature a number of antennae elements to create a unidirectional beam and cut down on sidelobes which directly translates into greater fidelity. This is important because sidelobes can generate clutter meaning it is easier for a target to fall into the notch filter. So no, the radius of the antenna does not play a large role in the maximum range of the radar, which is why the APQ-120 on the F4E has dramatically shorter range than the APG-68 despite being similar in size and the antenna on the APQ-120 being significantly larger. 

[okopanja]

13 minutes ago, Pede said:

Since we're being cheeky, technically a phased array has a larger effective area of antenna than a planar array because the elements are more densely packed together due to the usage of phase shifters but I'm guessing you didn't know that. 

Where did you see phased arrays in this topic? (rhetorical question)

13 minutes ago, Pede said:

I'm guessing you probably also didn't know that modern planar arrays actually feature a number of antennae elements to create a unidirectional beam and cut down on sidelobes which directly translates into greater fidelity. This is important because sidelobes can generate clutter meaning it is easier for a target to fall into the notch filter. So no, the radius of the antenna does not play a large role in the maximum range of the radar, which is why the APQ-120 on the F4E has dramatically shorter range than the APG-68 despite being similar in size and the antenna on the APQ-120 being significantly larger. 

Again bringing irrelevant example. We are not here to facilitate another nerf/buff war.

Discussion weather or not one seeker is better or other is not of much of use since:

1. none of you have access to the actual data.

2. radar modeling in DCS is not on the level that you can make the distinction beyond purely (invented) modeling parameters such as CCM.

In this respect what @Napillowrote about the diameter factor, for the above listed reasons may numerically play much larger role than potentially better and more sensitive electronics. Especially in case when 9 years pass between the 2, in the best case you can claim that electronics are on comparable level. However this is all in the domain of pure guessing, and I am perfectly happy with the current state in this respect.

What is relevant for this topic is application of new API to PL-12 as a test bed for the potential future SD-10. So far it appears that this API focuses primarily on modeling of guidance law with or without INS, with/without application of Kalman filter.

So far what I can see is that PL-12, despite it's range, exhibits much worse behavior than both SD-10 and AIM-120C, when deployed against maneuvering targets.

[okopanja]

@uboats here is a comparison of SD-10 vs PL-12 fired on the same HOJ non maneuvering target.

SD-10s tend to take lower altitude to some reason, but look like horizontally choose better intercept point, probably proportional navigation factor is higher?

PL-12s compensate less, but end up trailing the target.

This appears to be true even for non HOJ targets where PL-12 flying at mach 2.5-3 ends up trailing the hot maneuvering target in some cases. (need to make more tests on this).

 

Tacview-20230705-203737-DCS-Su-27 vs F-15 HOJ_multi.zip.acmi

[okopanja]

here is the diagram comparing first pair of SD-10/PL-12 from above tacview:

Notice

Chart 1: here you can see SD-10 suddenly pulling G for some reason. In contraqst Pl-12 remains regular until terminal phase, but at this point it simply lags behind.

Chart 2: not much rolling/turning until end. Observable is that SD-10 turns much sooner after ~30 sec.

Chart 3: Pl-12 is clearly faster and actually overtake SD-10, 2 reasons for that sudden G pulling after 30 seconds + much lower altitude

Chart 4: Not really interesting here.

Edited July 5, 2023 by okopanja

[okopanja]

The video made from tacview...

[ShadowFrost]

On 7/5/2023 at 2:30 PM, Pede said:

This is consistent with the Aim120's api across the board. Not only did it noticeably reduce the performance of the aim120c, but even more so to the aim54 when it was applied there. It's been said before, I believe even in this post, but the aim120 api is just not very good which is why the SD-10 is out performing the PL-12.

The new API has not been applied to the Aim-54. 

[Pede]

3 minutes ago, ShadowFrost said:

The new API has not been applied to the Aim-54. 

My mistake, they overhauled the flight model so that the api could be applied to it, but the api implementation hasn't actually occurred yet. 

[Wyvern]

@uboats
I would recommend to do a new poll before updating, just to get a clear answer after testing, since most people voted before having actual results

Given there is still a lot of conversation going on in the thread, i dont think the current community opinion here is clear yet

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[okopanja]

Not sure what went wrong here

 

[Wyvern]

He notched it, just a vertical notch, last second

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Edited July 10, 2023 by Wyvern

[Napillo]

On 7/8/2023 at 10:05 PM, Wyvern said:

He notched it, just a vertical not, last second

lol ok then... If it was notched, the missile should just keep going where it was going, my guess is it was still receiving guidance from datalink, and the INS was off a bit. If the radar turns on, it shouldn't continue to receive from datalink.