Welcome on the PPA repository for the packages managed by the Net4Sat project.
This PPA is signed using a GPG key, so you'll first want to include the signing key into your filesystem and instruct APT to use it to check packages from this repository. To do so, start by downloading the key to a path of your liking, for instance:
sudo mkdir /etc/apt/keyrings
curl -sS https://raw.githubusercontent.com/CNES/net4sat-packages/master/gpg/net4sat.gpg.key | gpg --dearmor | sudo dd of=/etc/apt/keyrings/net4sat.gpg
Next, you'll want to instruct APT that you want to fetch packages from
this PPA. Run the following command to create the appropriate file in
the /etc/apt/sources.list.d/ folder:
cat << EOF | sudo tee /etc/apt/sources.list.d/github.net4sat.sources
Types: deb
URIs: https://raw.githubusercontent.com/CNES/net4sat-packages/master/focal/
Suites: focal
Components: stable
Signed-By: /etc/apt/keyrings/net4sat.gpg
EOF
Change focal by jammy if appropriate.
You can also use the dev or testing components instead of or alongside stable depending on your needs.
Lastly, you want to populate APT's cache so it knows which packets are available from here:
sudo apt-get update
You're all set-up now, you can install any packet you want from here, e.g.:
sudo apt-get install pepsal