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Comment by sfifs | Hacker News Reader

If you can localize down to the range of a km? Can't you just shoot down optically? A giant dark plane blotting out the stars...

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An airplane at altitude doesn't blot out stars. Optical sensors are nearly useless, especially against a black aircraft at night.

Not to sound skeptical, but I've seen some stuff Ratheon was putting out at least 10-15 years ago and I think it had some pretty impressive optical sensors. Are we including the various infrared frequencies?

Optical and infrared sensors have improved a lot and can be a useful supplement but due to limited field of view and interference from weather you generally can't count on them for primary search. Unless the target is really time sensitive, B-2 mission planners try to fly at night in bad weather when those sensors are seriously degraded.

I doubt it. If people are able to photograph dark birds at night, I see no reason why a missile with much bigger optics and more efficient (wider band and monochrome) sensors wouldn't be able to find a plane.

I'm sure any modern IR missile can shoot down any current stealth plane if it knows the location to within a few kms.

There are FLIR images of thr F22, nothing extraordinary about it in the IR spectrum.

A lot of Russian planes have Electro Optical systems for targeting. Usually they are IR based locking onto hot engines and such like a typical Fox 2 (Heat seeking missile) Range of IR tracking is pretty small for head on planes and more importantly your missile needs to know where to look in the first place to acquire the target. Also stealth aircraft have reduced heat signatures making it harder to pick them out against the background. Also you have problems with determining contrast against the background due to diffraction.

Essentially the passive array in this article is in the class of "Early Warning Radar" which is used to alert Combat Air Patrol aircraft and SAM sites where to start looking for the contact.

If you wanted to use this with a networked radar guided missile you would have problems with terminal guidance. If the missile could acquire the target as it came into radar range for the radar cross section of a stealth aircraft, there is very little chance it would have the energy to track the target. It would essentially need to make a right turn midair to track on the target. All the while the missile's radar will be making the plane's RWR light up like a Christmas tree.

Recently in DC they detected a plane that did not respond to warnings. The optical system then also detected the plane and panic ensued. Problem was the radar system was showing a phantom and the optical system saw a nearby plane and thought it was confirming the phantom.

Tldr; it's complicated

https://www.thedrive.com/the-war-zone/31222/mysterious-airsp...

As we saw with both Iran and Russian AA teams shooting down passenger jets...

Don’t forget USA navy vessels shooting down passenger plane.

Hopefully the US has learned something in the past 32 years since that incident. It seems that even our allegedly sophisticated adversaries haven’t in the present time.

At least the Russian team was merely operating a Buk in a clandestine op in the middle of a field in Ukraine (and the US ship was technically in Iranian territorial waters in 1988 during an actual war), I’m curious what Iran’s excuse was shooting it down in their own property?... maybe we’ll learn more about it eventually. Bellingcat was able to provide the actual team member names and wiretaps of the Russian soldiers.

Yup, it seems to me that the optimal missile would use mid-course guidance before doing IR / visual light homing in the terminal phase.

All the stealth craft also included some IR avoidance as a matter of course, IR seeking missiles existed at the time these were designed. It's unclear if a more modern missile would still be sensitive enough to lock on and avoid chasing flares.

The techniques they used to decrease the IR visibility are pretty neat. The engine nozzles are over the wings and there are a lot of airflow tricks used to cool it down faster so from below there might not be enough plume to track from a surface launched missile coming, from below at least.

https://en.wikipedia.org/wiki/Northrop_Grumman_B-2_Spirit#In...

Conventional IR countermeasures (spatial, spectral etc.) really are becoming a thing of the past.

When you’re talking about terminal IR guidance on any modern missile, generally the IRCCM will be so good that the probability of defeat with a flare cocktail is below an acceptable risk threshold. DIRCM is the current answer to this problem and—to tie this in with the parent comment—renders terminal IR guidance much less effective than MMW or other RF guidance.

https://en.m.wikipedia.org/wiki/Directional_Infrared_Counter...

Flares don't do much against anything besides mid and short wave infrared.

It's impossible to hide from long wave IR sensors, which detect the heat signature of the plane itself, and not its exhaust.

there have been developments using the sound for terminal guidance to augment that.

They're also not quiet.

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