Lessons for China to learn from Ukraine conflict for Taiwan scenario

Michaelsinodef · Apr 14, 2022

Riddle said:
Ukraine who don't have experience with anti-ship missiles easily sunk a Russian flagship. does this call into question the effectiveness of defense systems on a ship?

We can't at this point still not definitively conclude if it was an actual ASBM or like the russians said, a fire (go look up russian navy and accidents, not to mention a disgruntled sailor could have commited arson like with the USS Bonhomme Richard fire).

Not to mention the actual specs of that ship is quite heavily outdated (designed in the 70s I think?), very inferior to most of the stuff in the PLAN.

Equation · Apr 14, 2022

Michaelsinodef said:
We can't at this point still not definitively conclude if it was an actual ASBM or like the russians said, a fire (go look up russian navy and accidents, not to mention a disgruntled sailor could have commited arson like with the USS Bonhomme Richard fire).

Not to mention the actual specs of that ship is quite heavily outdated (designed in the 70s I think?), very inferior to most of the stuff in the PLAN.

If it's a ASBM, do you think the CIA and other western intelligence had gave Ukrainians lots of help? After all they can easily provide satellite images to the Ukraine as to the location of the ship.

Michaelsinodef · Apr 14, 2022

Equation said:
If it's a ASBM, do you think the CIA and other western intelligence had gave Ukrainians lots of help? After all they can easily provide satellite images to the Ukraine as to the location of the ship.

I mean we already do know that NATO is helping Ukraine immensely already (satelite, early warning, radar etc.), so IF this was a case of it being hit with some ASBM, it most likely had a lot of help from NATO (the ASBM could very well be one supplied by a NATO country).

As for the real reason? Probably only something that we're gonna find out some time down the line (months), although the explanation by @Richard Santos in the russian military news thread #8224 seems quite possible as well.

Confusionism · Apr 14, 2022

AndrewS said:
You've got mountains in Taiwan, some of which are almost 4000m high.

That will cast a radar shadow that will block the surface and low altitudes

Dude, the island's tallest peak, Jade Mountain, is 3,952 meters high.
The average height of Taiwan's major mountain ranges is below 3,000 meters, and only some peaks exceed this height. The distance between the main mountain ranges in Taiwan and the west coastline of Taiwan is about 80 kilometers, while the distance between the Japanese island of Yonaguni and the west coastline of Taiwan is 210 kilometers. Using some high school trigonometric functions, it can be calculated that an airplane flying at an altitude of 10,000 meters in Japanese airspace can see over most of the west coastline of Taiwan's major mountain ranges. This altitude can be lowered somewhat if only ships in the Taiwan Strait need to be detected.

Gloire_bb · Apr 14, 2022

Riddle said:
Ukraine who don't have experience with anti-ship missiles easily sunk a Russian flagship. does this call into question the effectiveness of defense systems on a ship?

Well, there was a lot of big 'wrongs' with this cruiser(50 yrs old design), but it was a missile cruiser of the same age as Ticos nonetheless. if something should be done ASAP - that is ensuring:
-adequate training to modern threats(PLAN doesn't lack necessary targets and uses them a lot, but the question is how risk-averse the training is),
-ensuring that maintenance that was done as per documents was actually done. Especially threatening are cover uppers.
-combat survivability of Russian ships after battle damage was known to be neglected(since the 1960s Soviet ships were kinda designed to last for one salvo), but it was impressive how bad it has shown itself to be (two light ASCMs with 145 kg warheads sunk a cruiser). Chinese ship designs do have Soviet/Russian roots in the end, this should be checked at the very least.

Confusionism · Apr 14, 2022

FairAndUnbiased said:
For targeting purposes the signal strength at the satellite is not what is important, it is signal strength at ground that's important. Anti radiation munitions do not see the satellite received power, they see the ground transmitter power.

From the inverse square law the signal strength at 10 km is ~900x stronger than the signal strength at 300 km. Even for typical radio sidelobe strength of -10 dB that's still much more signal to work with than the satellite. And if there's drone overflight whose to say that the main lobe won't be detected?

Tuning a satellite TV antenna is totally different. Most TV satellites are one way broadcast transmitters, and there's very few of them so keeping them within line of sight is hard for average users who can't see exactly where the satellite.

I calculated the signal strength and gave the satellite tuning example to give you an idea of how important directivity is for communication satellite antennas. If the Starlink is a normal WiFi antenna, then it may make some sense for you to estimate it this way because you can probably assume that the signal is propagating evenly in all directions.

But Starlink's antenna is not.

And here's what the Starlink antenna looks like, and what it looks like when taken apart.

The first thing you'll notice is that instead of the signal transmitter and mount of a regular satellite dish, there is only a “dish” on the Starlink dish. And inside this dish is complex circuitry and semiconductor components. This is because Starlink's antenna is called "phased array attena", which is the similar "phased array" used for phased array radar.

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If you have probably heard of phased-array radar, you should know that the biggest advantage of this antenna is that it is well directed and can concentrate all the energy in a very small area, which is why Starlink terminals are able to achieve broadband satellite Internet through a very small antenna.

Confusionism · Apr 14, 2022

FairAndUnbiased said:
Some people think that Starlink nameplate specs are holy grail that means whoever uses it has invincible full internet access. Just gotta debunk.

And some people really need to know more about Starlink before they call themselves “unbiased”.

FairAndUnbiased · Apr 14, 2022

Confusionism said:
I calculated the signal strength and gave the satellite tuning example to give you an idea of how important directivity is for communication satellite antennas. If the Starlink is a normal WiFi antenna, then it may make some sense for you to estimate it this way because you can probably assume that the signal is propagating evenly in all directions.

But Starlink's antenna is not.

And here's what the Starlink antenna looks like, and what it looks like when taken apart.

The first thing you'll notice is that instead of the signal transmitter and mount of a regular satellite dish, there is only a “dish” on the Starlink dish. And inside this dish is complex circuitry and semiconductor components. This is because Starlink's antenna is called "phased array attena", which is the similar "phased array" used for phased array radar.

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If you have probably heard of phased-array radar, you should know that the biggest advantage of this antenna is that it is well directed and can concentrate all the energy in a very small area, which is why Starlink terminals are able to achieve broadband satellite Internet through a very small antenna.

All directional antenna have 4 distinct far field radiative regimes: 1. Main lobe 2. Rear lobe 3. Side lobe 4. Nulls. The nulls are undetectable, but the others aren't.

It is clear that you did not understand the physics of EM radiation. Phased arrays do not violate the fundamentals of antenna.

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Any antenna will interfere with itself. Even a phased array antenna, which corrects for this interference, will still have side lobe leakage.

Note figure 2 which shows a phased array antenna scanning. Notice how the side lobes never disappear. Also notice how there's multiple main lobes.

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Confusionism · Apr 14, 2022

FairAndUnbiased said:
All directional antenna have 4 distinct far field radiative regimes: 1. Main lobe 2. Rear lobe 3. Side lobe 4. Nulls. The nulls are undetectable, but the others aren't.

It is clear that you did not understand the physics of EM radiation. Phased arrays do not violate the fundamentals of antenna.

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Any antenna will interfere with itself. Even a phased array antenna, which corrects for this interference, will still have side lobe leakage.

Note figure 2 which shows a phased array antenna scanning. Notice how the side lobes never disappear. Also notice how there's multiple main lobes.

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Now comes the straw man argument.
No one has ever said that phased-array antennas are "absolutely" radiation-free in other directions. But the radiation intensity on the side lobe is much smaller than the main lobe direction, and the phased array antenna can concentrate most of the energy in a very small area through the interference of the main lobe. And the leakage of these energy can be completely mixed in the ambient noise. At least for cheap loitering ammunition, trying to detect this level of signal is basically impossible.

FairAndUnbiased · Apr 14, 2022

Confusionism said:
Now comes the straw man argument.
No one has ever said that phased-array antennas are "absolutely" radiation-free in other directions. But the radiation intensity on the side lobe is much smaller than the main lobe direction, and the phased array antenna can concentrate most of the energy in a very small area through the interference of the main lobe. And the leakage of these energy can be completely mixed in the ambient noise. At least for cheap loitering ammunition, trying to detect this level of signal is basically impossible.

How much weaker and what's the minimum signal power from the side lobes able to be detected?

Is this power higher or lower than power received at the satellite?

What is the angular divergence of the main lobe?

What's the ambient signal at 10-12 GHz?

These are the critical questions that you have not answered.

Lessons for China to learn from Ukraine conflict for Taiwan scenario

Michaelsinodef

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Equation

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Michaelsinodef

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Confusionism

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Gloire_bb

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Confusionism

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Confusionism

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FairAndUnbiased

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Confusionism

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FairAndUnbiased

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