Below are notes on how to copy NOAA weather images -- directly from weather satellites!
NOAA Polar Weather Satellite Tips
Prepared by Frank (N1UW) January 11, 2020
Satellites and Frequencies
These satellites have active APT (Automatic Picture Taking) working:
NOAA-15 137.62 MHz
NOAA-18 137.9125 MHz
NOAA-19 137.1 MHz
Notes: At AOS, Doppler shift is about 2.8KHz high and at LOS it is about 2.8KHz it is low.
Besides the usual defaults, make these changes:
Make sure the receiver gain setting is about 40 dB.
Set the mode to NBFM
Set the bandwidth to 32 KHz (maximum).
Notes: Use the up/down buttons to change the bandwidth or use the keyboard to enter “32” to the left of the decimal point. If you just type in a value and press “Return”, the bandwidth sets to zero and you must then use the up button to increase the bandwidth to greater than 1.0 before you can re-enter a value with the keyboard. I think this is a software glitch.
Set the frequency step value to 100 Hz.
Set the RECORD bit level to “8-bit”.
Check the “AUDIO” box and uncheck the “BASEBAND” box.
Notes: The WAV file will be written into the folder where the SDR# executable lies.
NOAA-APT Image Decoder Software
Go to https://noaa-apt.mbernardi.com.ar and download Windows x86_64 zip.
Unzip and install the software.
Notes: There is more advanced software available but I haven’t had the opportunity to try them. This software is easy to use and is a good first step.
Set your starting frequency 2.8KHz high.
Don’t forget to start recording audio at AOS.
Start out with your antenna vertically polarized. That seems to work best for me. Twist it to optimize signal strength.
Watch the frequency and track it as the satellite passes overhead. Doppler shift is very slow near AOS and LOS but very rapid when near zenith.
After you end the recording, start the NOAA-APT software, choose the WAV file for input and type in “BMP” for output.
Click on START and enjoy