There is a sizeable load of complete nonsense in this thread in terms of people’s complete lack of understanding about stealth and in particular radar low observability.
A stealth aircraft like the F-117, B-2, F-22 and F-35 is designed to reduce its radar signature to such a point it becomes impossible to track. It does this via two main methods: channelled radio frequency (RF) energy reflection and radar absorption materials (RAM). The second part is pretty straight forward – absorb the RF so you can’t be detected/tracked. The first part requires a bit of geometry knowledge to understand, but very basic.
A stealth aircraft is designed to reflect RF to 45, 135, 225 and 315 degrees (NE, SE, SW, NW). This is why all the surfaces are symmetrically aligned. Because of this its radar reflection to 0, 90, 180 and 270 degrees (N, E, S, W) is very small (and usually almost nothing thanks to RAM). Stealth designers make sure that enough RF is reflected to match background radiation, black holes can be detected.
While this may seem to be an incomplete solution, reflecting RF to the non-cardinal points of the compass makes an aircraft impossible to detect and track. Because its moving.
A moving vehicle will sustain a pretty solid angular relationship to something located in front of it, on its sides and behind it. But the angular relationship to something at 45, 135, 225 and 315 degrees will widely fluctuate.
Because of this the radar peak reflection areas are not exposed to any radar long enough to enable detection. The only way around this is if the aircraft begins to hover or the radar precisely matches its course and velocity, which since it can’t track it in the first place is impossible, or a very large number of radars are networked together to notice all the brief reflections (which is much easier to say than do on the scale needed to track a stealth aircraft).
Stealth is designed to work against the kind of radars and how they are positioned on the battlefield in relationship to the stealthy aircraft. Since different radar frequencies can be reflected and absorbed in different ways sometimes compromises have to be made. Also the lateral relationship between the aircraft and the radars need to be taken into account.
The reason JORN can supposedly detect and track the B-2 is it is not designed to face a radars operating from high above it, as over the horizon backscatter radars (like JORN) do by reflecting RF of the ionosphere (like an AEW&C flying at 240,000 feet) or at such low frequencies. However a stealthy aircraft like the US Navy’s A-12, if it ever flew, optimised to defeat radar from above, if it ever worked, could possibility defeat JORN. Of course this is assuming that the B-2A hasn’t been fitted with a new layer of 5-20 MHz RAM across the top of the aircraft…
