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Czech Passive Radar Detecting B-2 at 150 miles (2015)

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Re: Czech Passive Radar Detecting B-2 at 150 miles (2015)

#11

Post by kabouseng »

mikeyouse wrote: post #2

They do claim it works on all stealth planes including the F-35, but the B-2 is now 30 years old and was designed in the mid 1980s. Detecting it from 150 miles is impressive, but when they're equipped with 250 mile standoff air-to-surface missiles, ultimately not very useful. I'd be curious how much better the stealth is in the world of supercomputers and CFD for modern planes as well.

Well it's passive radar. So you don't have to outperform the stand-off range of the target, since you are invisible to the plane too.

Re: Czech Passive Radar Detecting B-2 at 150 miles (2015)

#12

Post by willvarfar »

whalesalad wrote: post #3

The B2 is relatively ancient as far as stealth tech goes. Also, most stealth aircraft are detectable on radar. The question is how big or small is the radar cross section. That’s not something this blog post digs into. Meaning, most of the time a B2 looks like a goose or a small animal. Correction on my part: The B-2 and F-35 have radar cross sections roughly the size of a marble.

A goose flying at 600mph?

Re: Czech Passive Radar Detecting B-2 at 150 miles (2015)

#13

Post by HumblyTossed »

mikeyouse wrote: post #2

They do claim it works on all stealth planes including the F-35, but the B-2 is now 30 years old and was designed in the mid 1980s. Detecting it from 150 miles is impressive, but when they're equipped with 250 mile standoff air-to-surface missiles, ultimately not very useful. I'd be curious how much better the stealth is in the world of supercomputers and CFD for modern planes as well.

> ...but the B-2 is now 30 years old and was designed in the mid 1980s.

Given that the B-52 is 65 years old, built with 1955's technology, I would expect something more sophisticated to have a longer shelf life than 30 years.

Re: Czech Passive Radar Detecting B-2 at 150 miles (2015)

#14

Post by madengr »

mikeyouse wrote: post #2

They do claim it works on all stealth planes including the F-35, but the B-2 is now 30 years old and was designed in the mid 1980s. Detecting it from 150 miles is impressive, but when they're equipped with 250 mile standoff air-to-surface missiles, ultimately not very useful. I'd be curious how much better the stealth is in the world of supercomputers and CFD for modern planes as well.

Not much. The F-117 is stealth mostly due to shape. The B2 stealth is mostly due to materials and construction techniques. You can run optimization routines to reduce scattering, but it’s not going to be huge improvements

This is a good book that discusses several techniques:

https://www.amazon.com/Radar-Man-Personal-History-Stealth/dp...

Re: Czech Passive Radar Detecting B-2 at 150 miles (2015)

#15

Post by HumblyTossed »

willvarfar wrote: post #12
whalesalad wrote: post #3

The B2 is relatively ancient as far as stealth tech goes. Also, most stealth aircraft are detectable on radar. The question is how big or small is the radar cross section. That’s not something this blog post digs into. Meaning, most of the time a B2 looks like a goose or a small animal. Correction on my part: The B-2 and F-35 have radar cross sections roughly the size of a marble.

A goose flying at 600mph?

It could happen:

https://en.wikipedia.org/wiki/Chicken_gun

Re: Czech Passive Radar Detecting B-2 at 150 miles (2015)

#16

Post by nitrogen »

kabouseng wrote: post #11
mikeyouse wrote: post #2

They do claim it works on all stealth planes including the F-35, but the B-2 is now 30 years old and was designed in the mid 1980s. Detecting it from 150 miles is impressive, but when they're equipped with 250 mile standoff air-to-surface missiles, ultimately not very useful. I'd be curious how much better the stealth is in the world of supercomputers and CFD for modern planes as well.

Well it's passive radar. So you don't have to outperform the stand-off range of the target, since you are invisible to the plane too.

Is there any risk of demodulator IF or other leakage from these receivers?

Re: Czech Passive Radar Detecting B-2 at 150 miles (2015)

#17

Post by vetinari »

whalesalad wrote: post #3

The B2 is relatively ancient as far as stealth tech goes. Also, most stealth aircraft are detectable on radar. The question is how big or small is the radar cross section. That’s not something this blog post digs into. Meaning, most of the time a B2 looks like a goose or a small animal. Correction on my part: The B-2 and F-35 have radar cross sections roughly the size of a marble.

It is a game of cat and mouse.

Yes, B2 is relatively ancient, but so is the Tamara passive radar (it was capable to detect B2 and F-117, in the 80'ies). Just like there is a newer stealth tech for planes, there is never stealth detection tech in radars.

Re: Czech Passive Radar Detecting B-2 at 150 miles (2015)

#18

Post by WalterBright »

HumblyTossed wrote: post #13
mikeyouse wrote: post #2

They do claim it works on all stealth planes including the F-35, but the B-2 is now 30 years old and was designed in the mid 1980s. Detecting it from 150 miles is impressive, but when they're equipped with 250 mile standoff air-to-surface missiles, ultimately not very useful. I'd be curious how much better the stealth is in the world of supercomputers and CFD for modern planes as well.

> ...but the B-2 is now 30 years old and was designed in the mid 1980s. Given that the B-52 is 65 years old, built with 1955's technology, I would expect something more sophisticated to have a longer shelf life than 30 years.

The B-52 is only useful after the enemy's air defense systems have been completely suppressed. It's mostly just a truck.

Re: Czech Passive Radar Detecting B-2 at 150 miles (2015)

#19

Post by nradov »

WalterBright wrote: post #18
HumblyTossed wrote: post #13

Earlier quoted context omitted.

> ...but the B-2 is now 30 years old and was designed in the mid 1980s. Given that the B-52 is 65 years old, built with 1955's technology, I would expect something more sophisticated to have a longer shelf life than 30 years.

The B-52 is only useful after the enemy's air defense systems have been completely suppressed. It's mostly just a truck.

The B-52 can also carry long range stand off weapons.

Re: Czech Passive Radar Detecting B-2 at 150 miles (2015)

#20

Post by amluto »

nitrogen wrote: post #16
kabouseng wrote: post #11

Earlier quoted context omitted.

Well it's passive radar. So you don't have to outperform the stand-off range of the target, since you are invisible to the plane too.

Is there any risk of demodulator IF or other leakage from these receivers?

Given that it’s entirely reasonable to build a 3 GHz baseband receiver these days, you don’t need IF. The whole thing can probably be made to radiate almost indistinguishably from a cell phone or computer.
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