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I though stealth as a concept was near obsolete due to cheap passive radar becoming feasible for about everyone? I didnt know they still built planes for this c

I though stealth as a concept was near obsolete due to cheap passive radar becoming feasible for about everyone? I didnt know they still built planes for this concept. https://en.wikipedia.org/wiki/Passive_radar https://en.wikipedia.org/wiki/Passive_radar

krapht 8y ago
Stealth is relative; as long as your detection distance is greater than the adversary's, you're good. Also, passive is great, but I'd expect in a war situation all large transmitters would get disabled first.
- LifeLiverTransp 8y ago
  All cellphone towers?
  - krapht 8y ago
    You don't have to worry about most small cell towers, since they are usually directional (pointed towards the ground to maximize signal coverage) and relatively low power. In the countryside with tall towers that cover tens of kilometers... well... it's kind of hard to miss those with a missile.
    - rbanffy 8y ago
      You can always mount the transmitters in trucks and keep moving. If you can pinpoint the source and fuse the input of, say, dozens of small sensors deployed all over the place, you can pinpoint the plane well enough.
      - krapht 8y ago
        Not well enough to do reliably do missile tracking, just enough to get an idea that yes, there is an object out there in the atmosphere. "Dumb" methods like TDOA / FDOA have quite bad limitations on resolution. Multistatic passive radar is quite hard to do at high performance. Radio astronomy observatories have been doing it for decades; it's expensive, requires high grade equipment to synchronize time and frequency, and reliable, real-time high-bandwidth data links.
twic 8y ago
You can use passive radar for surveillance radars, but is it any good for tracking and guidance radars? If your radar stations can see F-35s, but your interceptors and SAM batteries can't fire at it, the stealth is still useful.
ufmace 8y ago
That's getting awfully ahead of things. Showing that it's sometimes possible to detect aircraft like this is a long, long way from demonstrating that it's even theoretically possible to replace all existing air defense and targeting/interception radars with it under all circumstance, much less actually trying to do it.

krapht 8y ago

Stealth is relative; as long as your detection distance is greater than the adversary's, you're good. Also, passive is great, but I'd expect in a war situation all large transmitters would get disabled first.

LifeLiverTransp 8y ago
All cellphone towers?
- krapht 8y ago
  You don't have to worry about most small cell towers, since they are usually directional (pointed towards the ground to maximize signal coverage) and relatively low power. In the countryside with tall towers that cover tens of kilometers... well... it's kind of hard to miss those with a missile.
  - rbanffy 8y ago
    You can always mount the transmitters in trucks and keep moving. If you can pinpoint the source and fuse the input of, say, dozens of small sensors deployed all over the place, you can pinpoint the plane well enough.
    - krapht 8y ago
      Not well enough to do reliably do missile tracking, just enough to get an idea that yes, there is an object out there in the atmosphere. "Dumb" methods like TDOA / FDOA have quite bad limitations on resolution. Multistatic passive radar is quite hard to do at high performance. Radio astronomy observatories have been doing it for decades; it's expensive, requires high grade equipment to synchronize time and frequency, and reliable, real-time high-bandwidth data links.

twic 8y ago

You can use passive radar for surveillance radars, but is it any good for tracking and guidance radars? If your radar stations can see F-35s, but your interceptors and SAM batteries can't fire at it, the stealth is still useful.

ufmace 8y ago

That's getting awfully ahead of things. Showing that it's sometimes possible to detect aircraft like this is a long, long way from demonstrating that it's even theoretically possible to replace all existing air defense and targeting/interception radars with it under all circumstance, much less actually trying to do it.