gnss-sdr software package provides Global navigation satellite systems software defined receiver, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install gnss-sdr
gnss-sdr is installed in your system.
Make ensure the gnss-sdr package were installed using the commands given below,
$ sudo dpkg-query -l | grep gnss-sdr *
You will get with gnss-sdr package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Ham Radio |
| Package | gnss-sdr |
| Version | 0.0.8-1+b3 |
| Description | Global navigation satellite systems software defined receiver |
| Sub Section | hamradio |