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

Post by teruakohatu » Sat, Mar 14, 2020, 10:30 PM UTC

sfifs wrote: post #58

JDulin wrote: post #47

Earlier quoted context omitted.

More to the point, detecting a stealth aircraft is very different from shooting at a stealth aircraft. This radar would likely not have the location accuracy of where exactly the B-2 was to accurately engage it with a missile. Your accuracy would be limited by the rate of RF pings the B-2 is putting off, and then the margin-of-error of these RF waves and receiver. This is one difference between the B-2 and stealth fi…

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...

Post by DarkmSparks » Sat, Mar 14, 2020, 10:44 PM UTC

ChuckMcM wrote: post #26

Hmm, not your typical RADAR. This is basically using the RF emissions of the plane, and their detection at multiple RF detection stations with synchronized clocks, to determine the difference in arrival time. The radio emissions all travel at the same speed through the air, the difference in arrival time can be used with some simple trig to figure out where the RF emitter is. There are a number of Time Difference of…

Post by computerex » Sat, Mar 14, 2020, 10:48 PM UTC

m4rtink wrote: post #55

nradov wrote: post #42

Many people fail to understand that there's a huge difference between detecting the presence of an aircraft and actually targeting it. Anti-aircraft weapons must be precisely targeted to have any chance of hitting. So a passive radar can be useful in limited circumstances for cueing other sensors but it can't accomplish much by itself.

Could the adversary still just send cannon equipped fighters to the general that would locate the stealth bomber visually and shoot it to pieces ? Sure, could be rather hard to do in the night but once a stealth bomber is sighted visually, it is toast - B2 simply has no self defence weapons available at all. A stealth fighter could be better off if it can defend itself while still avoiding others getting a weapon loc…

Post by DarkmSparks » Sat, Mar 14, 2020, 11:07 PM UTC

greglindahl wrote: post #54

ChuckMcM wrote: post #26

Hmm, not your typical RADAR. This is basically using the RF emissions of the plane, and their detection at multiple RF detection stations with synchronized clocks, to determine the difference in arrival time. The radio emissions all travel at the same speed through the air, the difference in arrival time can be used with some simple trig to figure out where the RF emitter is. There are a number of Time Difference of…

> That said, they are "easy" to jam in the sense that when you have two radio signals on the same frequency, Not at all. Check out the VLBI technique from radio astronomy, it's not hard to tell that there are two discrete signals. But that's not really the point: you can see stealth aircraft already with lower frequency radars, just not well enough to shoot them down. It's hard to imagine this passive technique being…

Post by brian_herman » Sat, Mar 14, 2020, 11:23 PM UTC

jah wrote: post #40

ChuckMcM wrote: post #26

Hmm, not your typical RADAR. This is basically using the RF emissions of the plane, and their detection at multiple RF detection stations with synchronized clocks, to determine the difference in arrival time. The radio emissions all travel at the same speed through the air, the difference in arrival time can be used with some simple trig to figure out where the RF emitter is. There are a number of Time Difference of…

Here's an interesting variation that uses RTL-SDR's: https://dopplerfish.com/passive-radar/