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US Navy's High-Resolution Radar Can See Individual Raindrops In a Storm
coondoggie writes "The U.S. Naval Research Laboratory (NRL) researchers said recently that a Navy very high-resolution Doppler radar can actually spot individual raindrops in a cloudburst, possibly paving the way for new weather monitoring applications that could better track or monitor weather and severe storms. According to an NRL release, the very high-resolution 'Mid-Course Radar' was used to retrieve information on the internal cloud flow and precipitation structure. The radar was previously used to track small debris shed from the NASA space shuttle missions during launch. 'Similar to the traces left behind on film by sub-atomic particles, researchers observed larger cloud particles leaving well-defined, nearly linear, radar reflectivity "streaks" which could be analyzed to infer their underlying properties,' NRL stated."
means you can avoid individual rain drops and keep your battleship dry.....
"Boss, I'll need some special equipment to see our data in the cloud ..."
How many raindrops are there in a storm?
The Space Shuttle generally flew only under clear conditions (Challenger excepted, of course); I can't ever recall seeing a photo of the Shuttle taking off or landing in the rain.
Light rain, I can see this working, but a proper Texas Downpour (a.k.a. "cow pissing on a flat rock") is probably going to block the signal after 300m of heavy rain, even at higher energies. I'd be curious to hear what kind of rainstorms and what region of the country they were testing this in. Light mist in Seattle is very different from a tropical thunderstorm in Miami is very different from a squall line in Dallas.
moox. for a new generation.
If you can detect indvidual raindrops, I suspect detecting a marble sized radar target flying near or over the speed of sound is no problem whatsoever. While this radar is probably too big to put in a fighter a datalink from a ground based version to the fighter will solve that problem quite nicely.
>Doppler radar can actually spot individual raindrops in a cloudburst,
A raindrop, you say? Like what, a big one? Ok, that's 5mm across for the largest type. From here: http://hypertextbook.com/facts/2001/IgorVolynets.shtml
It's only a matter of time that other countries develop "weather radar" as pinpoint as this.
The F22 and F35 radar cross sections have been compared to a metal marble and a metal golf ball, respectively. Their "stealth technology" has just been rendered obsolete.
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BMO
Seeing individual raindrops, that's the problem with current weather radar technology.
Or could it be that it's already so expensive that they cannot blanket the country like
they need to and there are huge gaps in coverage which makes models less accurate?
-AI
For me, it is far better to grasp the Universe as it really is than to persist in delusion
Their Stealth technology has been obsolete since before they came out, as long as you can use a heavy-ass ground (or ship) based radar system. Russian S400 "Triumf" deals with stealth just fine, and so does S300 with minor mods. And by "deals" I mean shoots down stealth aircraft from beyond its missile range. That's why we haven't attacked Iran yet. That's not the point of stealth. The point of stealth is that _other planes_ can't see you, and you can take them out from way beyond _their_ radar range.
Stealth technologies are designed to change how an object that can be detected by RADAR is seen by it. Through various material changes, positioning of openings, angles, and the like, you can change how you appear on a RADAR and to a point minimize detection range. You do not have to penetrate foreign airspace much to get a bomb on target and drones don't incur the political risk of dead pilots.
Oh I do not doubt that current stealth technology can be rendered obsolete if not already in some cases, however while we read about breakthroughs in RADAR technology when it occurs we rarely read about stealth technologies until they are implemented or already surpassed.
Then comes the old standby, the military is most likely well prepared for not caring about stealth in the long run. With new weapon systems, drones, and the like, finding a stealth plane is least of the enemies worries.
* Winners compare their achievements to their goals, losers compare theirs to that of others.
Yes your post is consistent with the fact that the first stealth aircraft was - a bomber.
Seven puppies were harmed during the making of this post.
I've heard about politicians pissing away money on public projects, but this is really a watershed moment.
moox. for a new generation.
I said .042m/Sin (.00000413239/2) = 1164km
This is wrong.
I forgot to use the radius of the golf ball, which is .021
Which gives 582km instead, not 1164km
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BMO
I wish I could remember the author of a journal article I read a few years ago, but in it a mathematician suggested that the models used by weather forecasters were the problem. Some term or terms that were approximated or left out had bigger impacts then scientists thought. He was able to spot this because error in weather forecasts accumulated as the square root of time over the first few days, rather than the chaos-predicted exponential of time.
15 years ago my ex-girlfriend used to work on an atmospheric research radar design as a part of her thesis which was capable of seeing individual raindrops. Not sure what's the big deal here.
*: The name of the fighter's mothership shall be left as an exercise for the reader.
Unless you have a radar wavelength smaller than the size of a raindrop (\lambda 0.5 mm seems far-fetched), then you CANNOT SPOT INDIVIDUAL RAINDROPS. Furthermore, to achieve the kind of ANGULAR RESOLUTION required, would necessitate a HUGE-sized dish given that roughly speaking the diffracion limit is \Delta \theta ~ \frac{\lambda}{D}, where D = diameter of the dish. What the article says is that you can understand the size and distribution of MANY small raindrops in a cloud, which presumably before you could not. I am amazed how little basic physics /.-tters seem to know.
The point of stealth is to take out their radar sites. People declare that it's easy for radars to detect and shoot down stealth aircraft, but how easy is it for a stealth aircraft to blow up a radar site? I have to point out that no one has figured out how to make a stealth radar site yet. Think about this: the radar beam has to travel to the target, reflect, then travel back to the radar site to be detected by the radar. If the target has a bunch of antennas, it can detect the radar much earlier than the radar can detect it.
In any war, drones and cruise missiles will be the vanguard of the strike force. The UAVs will fly in to draw fire and jam radars, and cruise missiles will be used to hit anti-aircraft batteries that fire. Sure, in theory the radars can detect stealth aircraft but what about a real electronic warfare environment where we have jammers, target drones, and cruise missiles lighting up any radar site that turns on? The B-2 has its own electronic warfare suite, and as seen above, it can see radar sites much earlier than the radar sites can see them. And don't make any mistake: the radar sites are well within the reach of many of our aircraft. The S400 has a maximum engagement range of 400 kilometers. That is well within the range of the JSOW-ER with a small jet engine that can hit targets from 300 nm. The JASSM-ER has a range of 575 miles, which can be deployed by the B-2.
The B-2 carries the Joint Standoff Weapon (JSOW), which can hit targets from 60 nautical miles. There's a Small Diameter Bomb that can float 60 nmi. Any guy who turns on his radar will have a bad day, guaranteed.
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