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pix on main page updated


 

I have found what could be the source of all the satellite
pix you see on all those weather websites. The files at:



get updated as often as once every 8 minutes and are unprocessed and
do not have map overlays applied.

To me, the "weather products" one sees on commerical weather sites
look like processed version os these images.

So, I thought "Hey, I could hack my own satellite images." (rubbing
hands rapidly with glee).

I wrote a script to combines the 3.9, 6.75, 10.7 and 12.0 micrometer
infrared images of the south east ontario area.

I am trying to create a near-realtime map of clouds around the ottawa
area. The problem is dont understand the science that would allow one
to derive total cloud cover from sat images. So I played around with
a compositing algorithm. I'd say it so-so at the moment. When its
clear in ottawa, the map shows reasonably dark. Cloudy shows up
at grey or white. I think i'll need to keep tweaking it.

You can see the results on the OAFs mainpage. The image is quite small
to keep the processing times low. But I it gets updated as often
as every 8 minutes (NASA willing). I think that is cool since the
weather websites seem to do it only once per hour.

If you have ideas on how to make that image more useful, please
let me know. (I'd really like to know the algorithm for deriving
total cloud cover from sat pix.)

Clear skies, in near-realtime

-ad

"its wafer thin!"


Mike Wirths
 

Very cool Attilla!

Having images every 8 minutes would allow for a much nicer animation (it
always looks so choppy that I never get much of an idea of the actual
movement). We know a guy (Fred Richardson) that does some horse tranport for
us, he also happens to be an ex-parrot....No an ex- meteorologist! He might
be able to help you out I'll grab his e-mail when I go to the barn and pass
that on to you, hes a super nice guy and I'm sure he'd get a kick out of
what you're trying to do!

clear skies--

Mike W

-----Original Message-----
From: attilla.danko@... <attilla.danko@...>
To: OAFs@... <OAFs@...>
Date: Sunday, March 18, 2001 7:10 PM
Subject: [OAFs] pix on main page updated


I have found what could be the source of all the satellite
pix you see on all those weather websites. The files at:



get updated as often as once every 8 minutes and are unprocessed and
do not have map overlays applied.

To me, the "weather products" one sees on commerical weather sites
look like processed version os these images.

So, I thought "Hey, I could hack my own satellite images." (rubbing
hands rapidly with glee).

I wrote a script to combines the 3.9, 6.75, 10.7 and 12.0 micrometer
infrared images of the south east ontario area.

I am trying to create a near-realtime map of clouds around the ottawa
area. The problem is dont understand the science that would allow one
to derive total cloud cover from sat images. So I played around with
a compositing algorithm. I'd say it so-so at the moment. When its
clear in ottawa, the map shows reasonably dark. Cloudy shows up
at grey or white. I think i'll need to keep tweaking it.

You can see the results on the OAFs mainpage. The image is quite small
to keep the processing times low. But I it gets updated as often
as every 8 minutes (NASA willing). I think that is cool since the
weather websites seem to do it only once per hour.

If you have ideas on how to make that image more useful, please
let me know. (I'd really like to know the algorithm for deriving
total cloud cover from sat pix.)

Clear skies, in near-realtime

-ad

"its wafer thin!"









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--- In OAFs@y..., "Mike Wirths" <mwirths@s...> wrote:
Having images every 8 minutes would allow for a much nicer
animation (it
always looks so choppy that I never get much of an idea of the
actual
movement
It turns out that Nasa has already done that. Have a look
at this .mov file (warning 3meg):


/0000_latest.mov

(you may need to cut and paste that url onto so its one line)

Thats pretty much the smoothest animation i've seen on the web.
I'm not sure how often they update it, but as I am writing now,
the timestamp on the web page is only 20 minutes old.

Anybody know of a script-drivable program or library that can
be used to crop .mov files? I'd like to be able to create an animation
for the region around ottawa. (Mostly because it ought to be
a lot smaller than 3 meg). Something that bursts .movs into
individual frames and then collectes tham back again would be
almost as good.

Well, I figure, if we have to look at clouds ('cause it's cloudy)
it might as well be fun.

-ad

ps. i've posted this link to OAFs/booksmarks