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(meteorobs) Doppler Radar; Japan; Perseids in Hawaii
>
>Ummmm...I dislike being a naysayer, but based upon my limited knowledge of
>doppler radars, I don't think that they can be used to detect meteors.
>There are a few reasons for this:
>
Jim's pretty much got it all, except:
The current NWS doppler radar, the WSR-88D (NEXRAD) uses a scan strategy as
follows:
1 rotation at 1/2 degree elevation
1 rotation at 1 degree elevation
etc., increasing in elevation, until the last of 8 rotations is up at 65
degrees.
In this way it builds up a picture of a volume of airspace.
Then there's a couple of minutes of processing time, so the 'latest' picture
you see is around ten minutes old since the scan started.
Any given point is scanned only once in eight minutes, max. Not the optimum
for meteor detection.
The horizontal range of the thing is about 200 miles, I don't know what the
pulse duration and repetition rate is. The dopplers work by sensing the
motion and density of particulates in the air. I've seen some really cool
stuff of airborne insects on WSR-88Ds. I was at NCAR in Boulder, CO with
some of the thunderstorm wizards, and I saw them doing things like seeing
tiny convergence lines forming on the radar by the bugs and dust being
lifted in the air, and forecasting a line of thunderstorms to pop there,
which they promptly did, 30 minutes later.
But I digress... Meteor trains are not made of particulate matter, so would
not show on doppler.
>From: Lew Gramer <dedalus>
>Date: Mon, 02 Jun 97 14:52:18 -0400
>Subject: (meteorobs) FWD: IAU22: Companion Meetings/Tour IAU Kyoto Nippon
Meteor Society
>
>Is anyone from IMO or AMS participating in the following? Just curious,
>
>Lew
I'll be there, Lew. I'll be giving a brief presentation on the latest
happenings in the AMS. Jim Richardson is the official nominee to the Pro/Am
committee, but his schedule doesn't permit it, while mine does... barely.
While I'm on here, Lew, just let me mention that Meteor Group Hawaii will be
out in force for the Perseids this year, and if anyone happens to be in
Hawaii in August, we'd be glad to have you come watch with us, at our VERY
dark site on Mauna Loa.
Jim Bedient
AMS Electronic Information Coordinator
Honolulu, Hawaii