
US Navy's High-Resolution Radar Can See Individual Raindrops In a Storm - TomAnthony
http://www.networkworld.com/community/blog/us-navy%E2%80%99s-high-resolution-radar-can-see-individual-raindrops-storm
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josephhardin
As someone in the field, the only thing that really stood out about this radar
was it's incredibly small beamwidth(.22 degrees compared to a normal .8-1 for
most weather radars), and it's incredibly small range gates(.5 meters compared
to the 20 meters my radar operates at). That having been said, if this isn't a
dual polarization radar, which it sounds like it isn't, then this is still
significantly behind the state of the art.

The trend has been to move to higher frequency, lower power radars at X, Ku,
and Ka band. Also modern weather radars transmit both H and V polarizations
allowing us to measure the shape of the raindrops as well as retrieve full
drop size distributions. See <http://www.casa.umass.edu/main/research/> and
<http://pmm.nasa.gov/science/ground-validation/D3R> as examples of newer
systems.

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ck2
So why are we spending all this money on "stealth" fighters if essentially
other advanced countries like Russia can certainly have similar technology.

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tsotha
What makes you think this radar is any good at picking up an aircraft like the
F-22?

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stevenrace
But it may be great detecting small drones, however.

Filtering out all the noise, I suspect, is 'the hard part'. One would have to
detect objects in a point cloud and determine if their paths are
'organic/random' such as animals - versus those that take more direct paths...

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yock
The article doesn't mention anything about the physical dimensions or the
power requirements, but I wonder if putting this on a mobile platform would be
at all practical. It's one thing to put them on common storm paths, but
imagine aiming a few of these at different axis at a tornado. Being able to
analyze the motion of individual bits of debris in a tornado would teach us a
lot, I think.

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forgotusername
> 3MW power

So "not small" at a guess.

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shabble
That figure is almost certainly the peak pulse power, not the actual supply
requirements. Modern radar almost all operate by firing very very short pulses
at relatively low repetition rates[1]

I don't know about the system in question (and if it's still a prototype, it's
going to be bigger than it could be), but I think I've heard of systems with
similar pulse power being installed in (fighter) aircraft.

[1] <https://en.wikipedia.org/wiki/Pulse_repetition_frequency>

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vonmoltke
Fighter nose radars are still in the kilowatt range. Those systems are also
rather light (~700lbs all totaled, not counting coolant). There may be pylon-
mounted systems that get to the upper end of that (>100kW). High power
airborne radars are typically carried by larger, purpose-built platforms such
as the E-2C, E-3, and E-8.

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espeed
Will this help in detecting stealth aircraft since modern stealth aircraft
have signatures of large insects
(<http://en.wikipedia.org/wiki/Stealth_technology#Measuring>)?

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cjg_
Still need to distinguish between a large insect and a plane having the
signature of a large insect. Otherwise you'd have a lot of false positives.

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waterlesscloud
If it can track it continuously, I imagine speed will pretty much clear up any
confusion.

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cjg_
Yeah, continuously is the point here. The frequency of the data points is
largely dependent of the distance to the object. And you need to be able to
identify the object in two subsequent images.

I guess there's not that many insects at high altitudes either.

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BlackNapoleon
So this is what they're letting us know about...imagine what they're working
on now.

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tazzy531
Is this a "bug" that is being marketed as a "feature"?

It's great that you can see individual raindrops, but with radar, I'd think
you'd want to filter the raindrops out.

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ceejayoz
> It's great that you can see individual raindrops, but with radar, I'd think
> you'd want to filter the raindrops out.

Article says it was developed to spot stuff falling off the Space Shuttle
during launch, so no.

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IanDrake
PHP gets the spear, but objective-c gets a pass? I'm not a PHP dev, but at
least I can look at it and understand it.

Beauty is in the eye of the beholder I guess.

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IanDrake
Hah, how'd this get posted here! Sorry.

