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Re: Geography and NOAA_14



Hi Ken.  One thing you may want to consider is the bandwidth you obtain
with your scanner.  It is most likely too narrow to receive all the data
NOAA 14 is transmitting.  You are probably not getting all the bright
whites and the dark blacks.  I use a receiver with the bandwidth modified
to be wider and allow for all the NOAA 14 info.

Also, the NOAA 14 afternoon pass is an ascending pass which means the bird
is coming from the equator up over the US from south to north.  The
picture you get will be upside down.  You need to invert the picture to
mean anything.  The early morning passes are descending and you
will receive pictures coming from the north pole to your house.  Those
pictures will not be inverted.

Finally, the NOAA birds send two pictures side by side via APT (what you
are receiving as opposed to the high resolution pictures)  One picture is
visible light (the dark one) and the other is in infrared.  The infrared
pix is usually light grey with many spots of white.  This time of year,
the land will be much darker than the ocean because it is warmer.  In
winter, it is interesting to watch the Great Lakes get very white with all
the ice and cold temperatures.  You should easily pick out the Chesapeake
Bay, Delaware Bay, Cape Cod, the Finger Lakes, Newfoundland, etc.  I
usually get from Cuba up to far north into Canada from my station located
at 40 degrees North latitude.

The use of a sound board, a scanner and free software sounds great but you
are losing some image quality with the narrow band receiver.  The russian
weather birds (Met 3-5) send their pictures using a more narrow band
width.  

A turnstile antenna with circular polarization works real well.

Have fun with the birds.  The best pictures are from days when the
sun is off at an angle and there are great thunderstorms.  The
cumulonimbus clouds cast long shadows on the earth and you can actually see
they go up about 35,000 feet!

Rick, WB3CSY


 On Mon, 20 Jul 1998, Ken Freedman wrote:

> Hi Gang,
> 
>      My curiosity was piqued by the recent group of posts concerning
> weather sats, so I downloaded the WXSAT software and brewed up a cable to
> connect a scanner to my sound card.  To my absolute amazement, I was able
> to copy NOAA-14 this afternoon as it went by, using my 2 meter yagi.
> (crude, but it works!)  There seem to be two pictures, one (much) darker
> than the other.  My problem is: I haven't a clue what area of the world I'm
> looking at.  I don't recognize the terrain that is visible, and a half hour
> trying to match something in my Atlas to what I can see on the screen was
> fruitless.
> 
>      Should I have payed more attention in geography class?  Is there some
> way to know what that bird is transmitting??
> 
> 73, Ken
>  
> Ken Freedman
> AKA N1QQV/QRP  ARRL VE, QRP-L, AMSAT
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