Formed in 2009, the Archive Team (not to be confused with the archive.org Archive-It Team) is a rogue archivist collective dedicated to saving copies of rapidly dying or deleted websites for the sake of history and digital heritage. The group is 100% composed of volunteers and interested parties, and has expanded into a large amount of related projects for saving online and digital history.
NOAA APT Decoder
Decode analog, APT signals from the NOAA weather satellites.
Images are decoded from WAV files with a sample rate of 20800Hz. Files can be resampled using two methods.
Installation on Linux
sudo apt install git
pip install pillow numpy scipy
git clone https://github.com/zacstewart/apt-decoder
cd apt-decoder
Resampling
-
Method 1: Using a Python script with no additional dependencies.
cd apt-decoder python3 resample.py recording.wav resampled.wav -
Method 2: Using SoX and a bash script. This method is faster and filters the signal to improve the quality of the image.
sudo apt install sox cd apt-decoder ./resample.sh recording.wav resampled.wav
Usage
cd apt-decoder
python3 apt.py resampled.wav image_out.png
Images will probably look upside down if the satellite passed from south to north instead of north to south. In fact, the following examples are upside down.
Examples
Alternatives
You can also try wxtoimg but looks dead.
Alternatively atp-dec/apt-dec works really good. Keep in mind that the 1.7 release looks newer than the repo's master branch.