What causes weather radar "quirks"

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V Williamson
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What causes weather radar "quirks"

Unread post by V Williamson » September 20th, 2016, 7:44 pm

Can anyone tell me why the weather radar images sometimes include some spurious signals? What was happening near Esperance WA for a brief moment?
radar quirk.jpg
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jfoldbar
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Re: What causes weather radar "quirks"

Unread post by jfoldbar » September 21st, 2016, 4:50 am

its the fog dripping off a huge palm tree.

i wanna know how a radar can sometimes pick up rain on a sunny day

nilla60
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Re: What causes weather radar "quirks"

Unread post by nilla60 » September 21st, 2016, 9:50 pm

That image is a composite of various land based radar images. That "flower" is centered on the Esperance radar station:
http://www.bom.gov.au/products/IDR323.loop.shtml

http://www.bom.gov.au/australia/radar/i ... sperance32
"The Esperance Radar, which has its antenna mounted on 10 metre tower, thus providing coverage from 40 metres above sea level (M.O. at 30 metres ASL), has an unrestricted 360 degree view with no permanent echoes. Some anomalous propagation (AP) may occur within 20 kilometres of the radar site and provides a radar image of echoes appearing to dance around the station. When very hot conditions combined with northerly winds exist, speckled AP may be observed. "
Interesting, looks like it's a "thing" that people train-spot and Esperance has a tendency for that error:
https://ausradaranomalies.wordpress.com/

Shann Low
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Re: What causes weather radar "quirks"

Unread post by Shann Low » September 23rd, 2016, 5:00 pm

:crazy: :rolleyes:
Last edited by Shann Low on September 23rd, 2016, 5:04 pm, edited 1 time in total.

Shann Low
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Re: What causes weather radar "quirks"

Unread post by Shann Low » September 23rd, 2016, 5:03 pm

Those aren't the ONLY possibilities.
In Esperance, (as elsewhere) the weather bureaus radar array may not be the ONLY radar operating at any given time.
Radar both broadcasts a signal then looks for the reflected return signal to create its imagery. Whats to stop other broadcast radar signals, from being received by the sending array at the Esperance weather station?
Most all of the ships that use Esperance Port would have their own 72Mile open array Furuno radar units operating when arriving and leaving - as would many of the smaller commercial fishing fleet etc also have varying strength radar arrays operating at any given time!.
Radar when tuned appropriately cab even pick up the reflections from feathers on flocks of sea birds when diving on bait fish schools - but sometimes an unskilled, unqualified, inexperienced operator might interpret the radar returns as a rain event on a sunny day for e.g.
Most often it's just because people haven't seen a radar return of that kind before and aren't quite sure how to interpret it is all.

What does it indicate when a radar image distance is closing, but the bearing remains the same?

Peter Aawen
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Re: What causes weather radar "quirks"

Unread post by Peter Aawen » September 23rd, 2016, 5:24 pm

A contact on the radar with a Closing Range & a Steady Bearing is when you check the range setting, then look out on that bearing for the approaching aircraft aiming to do a flyover; & if there isn't one coming, you start to think pdq about what you gotta do at collision stations!! :eek:

Unless of course, that contact is dead ahead & just happens to be the port you're aiming to berth at; then you'd trim your toe nails! ;) (otherwise you'll wreak - or should that be 'rake' havoc on the sheets! :thumb: )

:p
An Ex-Service person is someone who thought enough about their country & how great it is, how lucky we are to live here, to write a blank cheque made out to 'The People and Commonwealth of Australia' for the value of 'Up to & including my Life!'

nilla60
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Re: What causes weather radar "quirks"

Unread post by nilla60 » September 23rd, 2016, 7:01 pm

I don't know much about radar, but have had a fair bit to do with satellite imagery. The faults typically reflect how the sensor works. Since the radar spins around on a post, I'd expect faults to have variations on a radial theme.

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