rakoczynskij@ncar.UCAR.EDU (Jurek Rakoczynski) (10/25/90)
From: asuvax!gtephx!rako!rakoczynskij@ncar.UCAR.EDU (Jurek Rakoczynski) Does anyone know anything more about an advancement in radar image processing that could track the B2 bomber and other stealth plane. I remember a report on the TV news that a few weeks after the rollout of the B2 for it's 1st flight, the Australian (some organization?) released information that they had developed a new algorithm that would look for counter-rotating vortices (from the wing tips) in the echo returns to indentify a plane in flight. This would negate any current stealth technology used on B2 and other planes. Heres some guesses/assumptions on my part: 1. In IEEE Spectrum dated July 1990, article 'Lookin over the horizon', discusses over-the-horizon radar. In there is a brief portion discussing the Australian Defense Science Technology Organisation experimenting with it's Jindalee radar. It is in quasi-operational status and is part of a future network of High Frequency Over the Horizon (HF OTH) radar. The US provided considerable assistance in the early stages of Jindalee. "For several years now, the Jindalee has also provided the Australian weather services with data on sea surface winds based on examination of the spectrum of the sea echo. Wind direction data derived from the U.S. Navy's Rothr (Relocatable OTH Radar) has been shown to compare favorably with Fleet Numerical predictions." 2. Assuming conventional radar is used measure the doppler shift of water droplets in a storm to track wind velocity, HF OTH may also be able to detect this. (I think Clear Air Turbulence-CAT is typically tracked with infrared.) 3. The exhaust of a jet plane adds alot of moisture in the air which would probably mix well with the vortex to reflect radar pulses. 4. As long as the vortex is not perpedicular to the radar beam, some doppler should should be measurable. 5. I didn't think the resolution of HF OTH radar could identify 2 counter- rotating vortices say 100 feet apart. No .sig yet. Standard disclaimers.