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# US Navy's High-Resolution Radar Can See Individual Raindrops In a Storm

#### samzenpus posted more than 2 years ago | from the needle-in-a-haystack dept.

161

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."

cancel ×

### Rule 34 (-1)

#### Anonymous Coward | more than 2 years ago | (#40490997)

Wow, they are already using it for detecting all the hard nipples in a 10 km radius?

### useful.... (5, Funny)

#### ushere (1015833) | more than 2 years ago | (#40491005)

means you can avoid individual rain drops and keep your battleship dry.....

### Re:useful.... (1)

#### captainpanic (1173915) | more than 2 years ago | (#40491447)

At least you know what just hit you.

### Re:useful.... (1)

#### Jeremiah Cornelius (137) | more than 2 years ago | (#40493901)

Signal? Meet noise!

### Re:useful.... (1)

#### X0563511 (793323) | more than 2 years ago | (#40494235)

Huge data set? Meet filtering and modern data-processing!

### Re:useful.... (0)

#### Anonymous Coward | more than 2 years ago | (#40492463)

it's not the rain drops you have to worry about its the pirates / ninja's in between them.

Also what happens if I hide a storm within a storm call it tell those drops apart?

### Re:useful.... (1)

#### Anonymous Coward | more than 2 years ago | (#40492777)

.... not to mention keeping stealth aircraft out of the rain. Hey jim! There appears to be a load of raindrops travelling horizontally at Mach2, I wonder what that could be?

### Re:useful.... (4, Insightful)

#### rtb61 (674572) | more than 2 years ago | (#40493021)

What it means is stealth is now meaningless technology, paying megabucks for a stealth fighter is simply throwing the tax payers money away. Once you can accurately track moisture in the atmosphere, then tracking ex-stealth aircraft is simply a matter of searching for and pinpointing areas of the sky not behaving like other areas of the sky. Specifically those areas of the sky which show a disturbance of where the aircraft has been, contrails http://en.wikipedia.org/wiki/Contrail [wikipedia.org] and where the aircraft actually is shock and compression waves http://en.wikipedia.org/wiki/Shock_wave [wikipedia.org] , even subsonic compression of the atmosphere by the passage of an aircraft substantially alters the amount of moisture in close proximity to the aircraft.

The US Navy might as well announce to the world, don't waste your money on the F35 or F22, what you want is a high durability aircraft. Stealth is utterly meaningless especially when the shape impacts durability and performance. Basically the only real defence is flying really low, as fast as possible and being the smallest target possible (cruise missile). Once you get above ground clutter, you'll announce your position, even if you stop and hover, your past passage will show up as well as your thrust plumes, jet or propeller.

No such thing as 'atmospheric' stealth no matter how advanced your technology unless of course you can jam or shut down the detection technology with even more 'advanced' technology (you can guess who I mean), the microchip being such an desirable target for at range energy fluctuations.

### Re:useful.... (1, Funny)

#### Anonymous Coward | more than 2 years ago | (#40493229)

Stealth aircraft use electrogravity tech to reduce their weight by a significant amount. You are incredibly misinformed.

### Re:useful.... (3, Insightful)

#### tnk1 (899206) | more than 2 years ago | (#40493447)

This may not yet be useful for real-time air defense purposes. The actual equipment my not be field mobile. Not to mention that getting data and analyzing over time it is one thing. Doing that while an aircraft comes at you at Mach 1.2 is a little different. Especially when it has a bomb or an anti-radiation missile with your name on it.

### Re:useful.... (1)

#### jimbolauski (882977) | more than 2 years ago | (#40494517)

How well will it work when radar jamming planes in the area jam this sensitive radar?

### An obvious BOFH bonus (5, Funny)

#### sunwukong (412560) | more than 2 years ago | (#40491029)

"Boss, I'll need some special equipment to see our data in the cloud ..."

### Re:An obvious BOFH bonus (1)

#### Kinky Bass Junk (880011) | more than 2 years ago | (#40491941)

Just in time for tax!

### Re:An obvious BOFH bonus (1)

#### NEDHead (1651195) | more than 2 years ago | (#40492611)

I appreciate the humor, but on a practical basis, the data analysis must be very similar to that being done at CERN - assuming they are doing serious data analysis. Trillions (ok, here goes, And Trillions) of drop trajectories, etc.

### Falling Liquid Drops... (0)

#### Clogoddess (2591147) | more than 2 years ago | (#40491031)

Dear NRL, I heard you are able to track falling drops of liquid. I would find it very useful if you could track falling birdshit and alert me to move my car, close my mouth, don a hat, etc. Yours Sincerely, Taxpayer.

### Gee whiz (1, Funny)

#### ozduo (2043408) | more than 2 years ago | (#40491033)

So instead of gazing at their navel the Navy can gaze at raindrops

### How many raindrops are there in a storm? (5, Funny)

#### evilsofa (947078) | more than 2 years ago | (#40491073)

How many raindrops are there in a storm?

### Re:How many raindrops are there in a storm? (0)

#### Anonymous Coward | more than 2 years ago | (#40491077)

42.
It depends on where you count them, but still 42.

### Re:How many raindrops are there in a storm? (0)

#### Anonymous Coward | more than 2 years ago | (#40491291)

rainman: 82 + 82 + 82, there's 246 raindrops
operator: there's 4 left in the cloud

### Re:How many raindrops are there in a storm? (1)

#### Thanshin (1188877) | more than 2 years ago | (#40492277)

And, more importantly, if you remove one drop, is it still a storm?

### Re:How many raindrops are there in a storm? (2)

#### damien_kane (519267) | more than 2 years ago | (#40492625)

And, more importantly, if you remove one drop, is it still a storm?

Only if it falls in the woods

### Re:How many raindrops are there in a storm? (0)

#### Anonymous Coward | more than 2 years ago | (#40492831)

the answer is blowin' in the wind

### Space technology again (1)

#### obeythefist (719316) | more than 2 years ago | (#40491097)

So, another solid example of the "Pure science and engineering" stuff that NASA does bleeding into real world applications.

Kind of.

### Re:Space technology again (1)

#### craigminah (1885846) | more than 2 years ago | (#40491993)

Even with the best data in the world, weather reporters would fubar 50% of all forecasts. Individual raindrop tracking seems pointless for predicting weather anyways...

### Re:Space technology again (2)

#### ancienthart (924862) | more than 2 years ago | (#40492101)

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.

### Re:Space technology again (2)

#### M1FCJ (586251) | more than 2 years ago | (#40492161)

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.

### Re:Space technology again (0)

#### Anonymous Coward | more than 2 years ago | (#40492781)

the big deal is this is the 15 to 20 years in the future when that radar is finally breaking out of the purely experimental world

### ...Under what circumstances? (2, Interesting)

#### Hadlock (143607) | more than 2 years ago | (#40491107)

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.

### Re:...Under what circumstances? (4, Funny)

#### Hadlock (143607) | more than 2 years ago | (#40491119)

Might as well karma whore this myself, because someone else is going to, here's a brilliant quote from HHGTTG:

Rob McKenna had two hundred and thirty-one different types of rain entered in his little book, and he didn't like any of them.

Since he had left Denmark the previous afternoon, he had been through types 33 (light pricking drizzle which made the roads slippery), 39 (heavy spotting), 47 to 51 (vertical light drizzle through to sharply slanting light to moderate drizzle freshening), 87 and 88 (two finely distinguished varieties of vertical torrential downpour), 100 (postdownpour squalling, cold), all the sea-storm types between 192 and 213 at once, 123, 124, 126, 127 (mild and intermediate cold gusting, regular and syncopated cab-drumming), 11 (breezy droplets), and now his least favorite of all, 17.

Rain type 17 was a dirty blatter battering against his windshield so hard that it didn't make much odds whether he had his wipers on or off.

And as he drove on, the rain clouds dragged down the sky after him for, though he did not know it, Rob McKenna was a Rain God. All he knew was that his working days were miserable and he had a succession of lousy holidays. All the clouds knew was that they loved him and wanted to be near him, to cherish him and to water him.

### Re:...Under what circumstances? (0)

#### Anonymous Coward | more than 2 years ago | (#40494385)

But is it 'a greater analyst than the Googleplex Star Thinker in the Seventh Galaxy of Light and Ingenuity which can calculate the trajectory of every single dust particle throughout a five-week Aldebaran sand blizzard?'

### Re:...Under what circumstances? (0)

#### Anonymous Coward | more than 2 years ago | (#40491151)

This system if flawless if the weather cooperates enough so that it only rains one drop at a time! Otherwise, it's ... not so flawless.

HTH! HAND! 8^)

### Re:...Under what circumstances? (2)

#### c0lo (1497653) | more than 2 years ago | (#40491339)

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.

Depends how high those higher energies: around 20 kt might improve the visibility for 1-2 km.

### Re:...Under what circumstances? (4, Informative)

#### Hadlock (143607) | more than 2 years ago | (#40491531)

Anyways, my point is, you start beaming enough energy through the atmosphere and you can have some unwanted effects. I'm sure the aluminum frame of a Cessna 172 acts as enough of a Faraday Cage against these sorts of things, but with your balls literally on the line, do you really want to test out that theory? ;)

### Re:...Under what circumstances? (2)

#### ciderbrew (1860166) | more than 2 years ago | (#40491753)

Yeap. Got a friend in the Navy who works on radar kit. He took himself down the sperm bank and had a batch frozen. I'd not like to work in a job that can kill your balls; but he didn't seem to be that bothered.

### Re:...Under what circumstances? (0)

#### Anonymous Coward | more than 2 years ago | (#40492499)

just put some of those special glasses on your balls and you're good

### Re:...Under what circumstances? (1)

#### fufufang (2603203) | more than 2 years ago | (#40493755)

I am surprised that the environmentalists haven't picked this up...

### The Muzzies are coming (-1)

#### Anonymous Coward | more than 2 years ago | (#40491109)

The Muzzies are coming, The Muzzies are coming
Every on keep calm
They're evil and thy're violent
And mean to do us harm

### So much for stealth (5, Interesting)

#### Melkman (82959) | more than 2 years ago | (#40491113)

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.

### Re:So much for stealth (1)

#### RigrmRtis (2044716) | more than 2 years ago | (#40491289)

Detecting a stealth aircraft and being able to identify what you've detected as a stealth aircraft are two completely different animals.

### Re:So much for stealth (4, Insightful)

#### Chrisq (894406) | more than 2 years ago | (#40491393)

Detecting a stealth aircraft and being able to identify what you've detected as a stealth aircraft are two completely different animals.

I think that any "marble sized" object travelling near mach-1 would be suspicious

### Re:So much for stealth (1)

#### piripiri (1476949) | more than 2 years ago | (#40491497)

It could be a bullet.

### Re:So much for stealth (0)

#### Anonymous Coward | more than 2 years ago | (#40491535)

Bullet with a flight path equidistant to the earth's surface at 40,000 feet, no ballistic arc, and without slowing down?

If they find that bullet, I'd recommend evasive action either way.

### Re:So much for stealth (2)

#### Chrisq (894406) | more than 2 years ago | (#40491607)

It could be a bullet.

Or even atom ant [wikipedia.org]

### Re:So much for stealth (1)

#### X0563511 (793323) | more than 2 years ago | (#40494319)

Indeed. I've never heard of any fighters or self-powered munitions being that small.

### Re:So much for stealth (1)

#### X0563511 (793323) | more than 2 years ago | (#40494337)

Clarify: i'm looking at the hole in the rain where the object is, not the radar cross-section of the object itself.

So yea, it might look on the scope like a marble, it's also got a jet-fighter or cruise-missile shaped hole in the rain around it, and they would apparently be able to see this now.

### Re:So much for stealth (0)

#### Anonymous Coward | more than 2 years ago | (#40493473)

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.

And supposing you want to attack and not to defend, how exactly are you going to build ground based radars on enemy territory? Please note that the 'tower rush' strategy from Warcraft 3 is not working in real life ^^

### Re:So much for stealth (0)

#### Anonymous Coward | more than 2 years ago | (#40494479)

Dunno, a couple skycranes, air superiority, a near-shore cargo vessel with escort. Additional options would be a hovercraft or blimp/rigid airship.

It's not like we don't have the money to produce all of these and have all three incoming to drop them off in ever decreasing distance from our targets :)

### Military Obsolescence. (2, Insightful)

#### bmo (77928) | more than 2 years ago | (#40491159)

>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 [hypertextbook.com]

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.

--
BMO

### Re:Military Obsolescence. (1)

#### JockTroll (996521) | more than 2 years ago | (#40491197)

Oh, don't worry. They have this instance covered. They'll serve cease & desist letters to any country who tries to develop system that could threaten the US investments in technology. Then they'll file a court order to those countries to bomb themselves.

### Re:Military Obsolescence. (0)

#### Anonymous Coward | more than 2 years ago | (#40491323)

>slashdot

Do you know where you are?

> His sig

### Their Stealth technology has been obsolete since b (3, Informative)

#### melted (227442) | more than 2 years ago | (#40491271)

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.

### Re:Their Stealth technology has been obsolete sinc (0)

#### Anonymous Coward | more than 2 years ago | (#40491361)

Until the russian equipment have shot down a raptor (or even a jsf, which is much easier target), I would be very skeptical about their claimed capabilities. And that skepticism goes both ways. Afaik the raptor is yet to see actual combat.

### Re:Their Stealth technology has been obsolete sinc (2)

#### Dunbal (464142) | more than 2 years ago | (#40491719)

Yes your post is consistent with the fact that the first stealth aircraft was - a bomber.

### Re:Their Stealth technology has been obsolete sinc (1)

#### Tastecicles (1153671) | more than 2 years ago | (#40491981)

Nope. The Fokker E.III was a fighter.

### Re:Their Stealth technology has been obsolete sinc (2)

#### Thanshin (1188877) | more than 2 years ago | (#40492329)

*: The name of the fighter's mothership shall be left as an exercise for the reader.

### Re:Their Stealth technology has been obsolete sinc (0)

#### Anonymous Coward | more than 2 years ago | (#40492945)

Russian S400 "Triumf" ... shoots down stealth aircraft from beyond its missile range.

I had to read that twice. I thought to myself that if the Russian S400 can shoot down aircraft from its own missile range, that's quite impressive. Then I realized you were talking about the aircraft's missile range.

### Re:Their Stealth technology has been obsolete sinc (4, Informative)

#### darkmeridian (119044) | more than 2 years ago | (#40494351)

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.

### Re:Military Obsolescence. (0)

#### Anonymous Coward | more than 2 years ago | (#40491325)

Did you even bother to read the article? Of course you didn't. Here, let me read it to you and tell you why your completely wrong:

They used a 3MW radar (that's MEGAWATTS, highly powerful, ground based, impossible to put on an airplane as most AESA's output about 12kW PEAK) , operating at 2km (ridiculously close), with a 0.22 degree beam width (i.e. very high gain antenna, therefore extremely directional and super super narrow). If your F22 or F35 needs to be within 2km of your radar for it to detect it, you've already lost the battle because he dropped a guided missile towards you 5km away.

This was only a proof-of-design concept which cant be fielded for 20 years, assuming anyone chooses to fund this to miniaturize it and make it feasible for warfare. If anything, it *might* be useful for weather station purposes. Cant you imagine your local weather reporter saying they have the newest "Doppler 3Million" to predict tomorrow weather?

### Re:Military Obsolescence. (3, Informative)

#### bmo (77928) | more than 2 years ago | (#40491715)

They claim they can see a rain drop out to 2 kilometers.

Fine. Let that be our upper limit for angular diameter. We shall use the largest rain drop of .005m (5mm, but .005m for the sake of units) mentioned earlier to figure this out. We shall then use the angular diameter to figure out how far a golf ball has to be to be the same apparent size (angular diameter).

Using the large raindrop is our best bet for reality. It keeps us from pushing out the golf ball sphere to ridiculous distances.

Here, let's do some math.

Since unicode sucks here, it goes like this:

Angle = 2 x Arcsin(radius of sphere divided by distance)

For a flat circle, it's an arctan but we're not using a flat circle. At this distance and size of targets, it doesn't make much difference, but we're using the correct formula for formality's sake.

Angle = 2x Arcsin(.0025 / 2000m)

0.000143239 degrees, or about .5 seconds (take number, multiply by 3600)

A golf ball is 42.67mm in diameter at a minimum, but let's just truncate this for simplicity and readability, and the error makes the radius of detection smaller. .042m/Sin (.00000413239/2) = 1164km

1164km = maximum effective range to detect a steel golf ball with this radar as long as you can detect the signal (for clarity, I am omitting signal strength and inverse-square law and what it does to detector size).

But then you say "read the article"

>With such small pulse volumes, it becomes possible to measure the properties of individual raindrops greater than 0.5mm

Their minimum raindrop is 1/10 smaller in diameter than the one used in this post. If I had put in .5mm in for calculating angular resolution, I would have pushed out the steel ball 10x the distance, a credulity straining distance.

Stealth is toast. It is obsolete.

QED.

Note: Please do not confuse angle of detection with beam width.

--
BMO

### Correction. (4, Informative)

#### bmo (77928) | more than 2 years ago | (#40491747)

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

--
BMO

### Re:Correction. (0)

#### Anonymous Coward | more than 2 years ago | (#40493543)

You are right about being obsolete. A stealth bomber would have to fly outside the orbit of the International Space Station to be undetectable.

Last time that I checked, you couldn't fly a stealth bomber to the ISS.

Nathan

### Further correction. (0)

#### Anonymous Coward | more than 2 years ago | (#40493861)

It's still not right. You typoed the angle from 0.000143239 degrees to 0.00000413239 degrees. Putting in the correct value, we get:

.021m/Sin (0.000143239/2) = 17km

which is substantially lower than your figure. In situations like this, I'd recommend using a much simpler approach: a 42.67mm golf ball, compared to a 5mm raindrop, is (42.67/5) ~= 8.5 times as large, so it has the same apparent size when it's 8.5 times as far away. 8.5 * 2km = 17 km, as above.

You were very careful about the precise definitions of the angles involved; but in a case like this, it makes no more than a one-in-a-million (or, rather, 5mm in 2km) difference in your final answer, and it increases the odds that you'll make a mistake.

### Re:Military Obsolescence. (0)

#### Anonymous Coward | more than 2 years ago | (#40493047)

Your math is wrong. Here's a quick and dirty proof:
5mm/2km = 50mm/20km

Yeah, we're using slope instead of angle. Which is a reasonable approximation for such small angles.

### ANALYSIS (1)

#### spectrokid (660550) | more than 2 years ago | (#40491625)

Someone wrote: "how many raindrops are there in a cloud?" I ask, "how many terrabytes are there in a cloud?. And will you be able to find the golf-ball in that cloud? Or does the USS Whatchemagot have BigBlue under the deck?

### raindrops are not designed to misdirect observatio (2)

#### Shivetya (243324) | more than 2 years ago | (#40491631)

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.

### Re:raindrops are not designed to misdirect observa (1)

#### bmo (77928) | more than 2 years ago | (#40491813)

>Explaining what stealth is

Dude... don't do that. We know what it is. And for those who don't, google is --->over there.

>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.

I was talking about the planes we have built. If you can detect a .5mm raindrop, at 2km, you sure as hell can detect a 42mm ball bearing - the current (optimistic) radar profile of the F35.

These airframes need to be relevant for the next 25-30 years (look at the life of the f-14, f-111, f-16, f-18 Hornet and Super Hornet, f-15 Eagle and Strike Eagle for comparison).

Somehow I don't think the stealth capabilities are going to be relevant in 5 years.

--
BMO

### Re:raindrops are not designed to misdirect observa (0)

#### Anonymous Coward | more than 2 years ago | (#40492461)

What if we do some EW and raise the noise floor?

### Re:raindrops are not designed to misdirect observa (1)

#### X0563511 (793323) | more than 2 years ago | (#40494393)

Jamming only works for so long, and it pretty much says "HERE I AM" after you "burn through" it. Imagine someone shining a super-bright flashlight in your face. Can't see now? That's jamming. However, put on some welding goggles (burn through the jamming) and suddenly that blinding glare is merely a point of light telling you EXACTLY where that person is.

### Re:Military Obsolescence. (2)

#### Greyfox (87712) | more than 2 years ago | (#40492947)

Obsolete... for the USA... yes. I bet most of the guys we sell radars to don't get the new-fangled current-generation radars. They probably get the crappy old ones that still can't see our stealth planes.

And once we do start selling them, I bet we could harass our enemies by shooting golf balls with stealth fighter profile into their air space. That'd be hysterical. Just sit a ship out in international water and use an air cannon or something to fire a constant stream of "stealth fighters" into their airspace.

### Re:Military Obsolescence. (1)

#### azalin (67640) | more than 2 years ago | (#40493667)

I do have to admit, that I would really like to see the golfball gattling in action

### Re:Military Obsolescence. (1)

#### Greyfox (87712) | more than 2 years ago | (#40494077)

I bet the Mythbusters would be happy to whip one up on the thinnest excuse of a myth. Just sayin'...

### Re:Military Obsolescence. (1)

#### X0563511 (793323) | more than 2 years ago | (#40494417)

Oh god, I love that idea. ... and then, in the middle of it, you send the actual attack craft. "Guess which one's real, assholes!"

### Re:Military Obsolescence. (0)

#### Anonymous Coward | more than 2 years ago | (#40494133)

TFA says they can spot individual raindrops in a storm. They didn't say they can spot EVERY raindrop in a storm. I think picking an anomaly out of the entire storm to indicate a stealth aircraft would be very unlikely.

### Cause that's the problem (2)

#### AlienIntelligence (1184493) | more than 2 years ago | (#40491171)

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

### Re:Cause that's the problem (2)

#### kerrbear (163235) | more than 2 years ago | (#40492861)

"And now to Chet Stevens for the weather. Using the State's most accurate Doppler Channel 7 Radar." "Thaaanks Judy, moving to the corner of 5th and High st. we notice that 7,276,544 raindrops have fallen at that intersection in the last 2 minutes. However the recent 5 seconds have only seen 125,465 raindrops indicating that the volume of rain is trending downwards, so if you're waiting at that corner to turn left onto High St. you might just wanna wait a few more seconds before turning for your own safety..."

### Stealth technology.. (1)

#### MnemonicMan (2596371) | more than 2 years ago | (#40491213)

So, now that the current generation of stealth coatings on airplanes is obsolete, how long before the US starts to both A) Sell current-gen stealth to other countries, and B) develop next-gen stealth capability.

Remember, stealth doesn't mean a plane is invisible, it just means that the cross section of the plane is just too small to image using normal radar.

### Re:Stealth technology.. (0)

#### Anonymous Coward | more than 2 years ago | (#40491859)

I guess the next-gen stealth has been under development even before they started building the current generation. Good luck getting any sales though if they're so expensive even the US doesn't want them.

Any radar can detect a stealth aircraft if you plop it right in front of the antenna, the question is how far it needs to be to remain undetectable. The closer the better.

### seeing individual raindrops in a storm (0)

#### Anonymous Coward | more than 2 years ago | (#40491217)

is about as useful as slashdot these days.

### But can the radar see (-1)

#### Anonymous Coward | more than 2 years ago | (#40491245)

the useless bloody wars the US regularly starts? The fascism and corporate plutocracy happening in the Homeland? The hatred and disgust of the other countries the current foreign policy causes? The shitty end the Empire is headed down for?

Can't you see?

### Wavelength and TX power? (1)

#### aglider (2435074) | more than 2 years ago | (#40491275)

I wonder about those two almost insignificant characteristics and related health azards.
Any idea?

### Re:Wavelength and TX power? (1)

#### gtall (79522) | more than 2 years ago | (#40493751)

Think putting your balls in a microwave.

### Re:Wavelength and TX power? (1)

#### Glothar (53068) | more than 2 years ago | (#40494163)

Is that because its an accurate analogy, or because you find it personally amusing?

### If you can see the raindrops (1)

#### djl4570 (801529) | more than 2 years ago | (#40491297)

Then you can see a stealth aircraft displacing those raindrops.

### Re:If you can see the raindrops (1)

#### ThatsMyNick (2004126) | more than 2 years ago | (#40491363)

Stealth aircraft have a large radar signature than raindrops. Most are atleast golf ball sized. If the radar can process so much information (which I doubt), then yeah they can detect stealth aircraft.

### So? (1)

#### tsa (15680) | more than 2 years ago | (#40491343)

I can do that too. What's the big deal?

### Great (1)

#### detritus. (46421) | more than 2 years ago | (#40491353)

Now I can't even take a piss in the woods without the government keeping track of the stream?

### Re:Great (1)

#### PolygamousRanchKid (1290638) | more than 2 years ago | (#40491491)

Now I can't even take a piss in the woods without the government keeping track of the stream?

Now I can't even take a piss in the woods without the government taxing the stream?

### Re:Great (2)

#### Hadlock (143607) | more than 2 years ago | (#40491727)

I've heard about politicians pissing away money on public projects, but this is really a watershed moment.

### How about a link to the actual press release? (0)

#### Anonymous Coward | more than 2 years ago | (#40491399)

http://www.nrl.navy.mil/media/news-releases/2012/nrl-scientists-track-individual-raindrops-inside-clouds

### walking speed in the rain (0)

#### Anonymous Coward | more than 2 years ago | (#40491445)

Great, hopefully this will help me to work out a formula for a minimum droplet saturation walking speed when caught in the rain.

### Any takers? (1)

#### thexile (1058552) | more than 2 years ago | (#40491459)

It is a Retina radar! Anyone?

### To see is one thing, to memorize another... (1)

#### dragisha (788) | more than 2 years ago | (#40491575)

And to manipulate such quantities of data - yet another thing.

And that another another thing is something to think about here. To calculate from raindrop up, or to take chaos theory shortcuts?

I really don't know much about meteorology and chaos theory, but I am sure people thinking about individual raindrop approach do not know, too!

### So they saw me pee in backyard (0)

#### Anonymous Coward | more than 2 years ago | (#40492195)

So they saw me pee in backyard...i was just giving back to nature honest....had nothing to do with beer

### I have a better idea (0)

#### slashmydots (2189826) | more than 2 years ago | (#40492865)

Most weather services can't even tell me what the temperature is right now or was yesterday. Maybe they should focus on reliably telling what the temperature will be and what the precipitation will be like before they start calculating individual raindrop trajectories.

Oh and by the way, this is impossible and they're lying. If there's a raindrop 500 feet into a pillar of rainfall, chances are it will be blocked so the radar waves would bounce off a raindrop closer to the edge first before even hitting an interior one. That's how radar works, after all. So they could track 1 raindrop on the very outer edge of a storm I guess, but that's even more useless.

### A step towards Total Perspective Vortex (1)

#### beschra (1424727) | more than 2 years ago | (#40493103)

Increase the resolution and apply to fairy cake and we're good to go!

### Nostradamus predicts (1)

#### Zhevranacci (2673457) | more than 2 years ago | (#40493115)

there will eventually exist lawsuits where somebody did not receive their "tornado is hitting your house in 5 minutes" warning phone call/text message.

### Migrating bird counts (0)

#### Anonymous Coward | more than 2 years ago | (#40493195)

Well , this could be useful for detecting and counting migratory birds , provided that it doesn't fry them in flight.

### Naval technology utilization plan (1)

#### nopainogain (1091795) | more than 2 years ago | (#40493209)

What it can do----detect moving raindrops from space. What it will end up doing---sitting under a tarp in a warehouse in Virginia til it's yard saled to a foreign country in 2024

### RTFA: the /. header is non-sensical (4, Insightful)

#### cpotoso (606303) | more than 2 years ago | (#40493987)

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.

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