Breakthrough Listen REU 2023 GNU Radio materials

This repository contains miscellanous materials used on the GNU Radio tutorials of the Breakthrough Listen Research Experience for Undergraduates summer program. The material was elaborated in the context of the collaboration between GNU Radio and SETI Institute.

Outline

The material is organized in the following folders:

Session 1. introduction-slides. some introductory slides for the tutorials.
Session 1. audio. A simple example showing how to generate and display audio (soundcard) signals with GNU Radio.
Session 1. rtl-sdr. A simple example showing how to receive signals with the RTL-SDR in GNU Radio.
Session 2. spectral-analysis. Shows how to simulate narrowband and wideband signals and how to do custom spectral analysis with FFTs. Includes real world example applications with a spectral line (W3OH maser) and a spacecraft (Voyager-1) recording.
Session 3. scripting. Shows how to control a flowgraph using Parameter blocks by running it from the command line or from Python. As a demo, there is an "observation" with an RTL-SDR scanning different frequencies and producing IQ and waterfall data.
Session 4. doppler. Shows how to do a simulation of a signal having constant Doppler drift using a sawtooth Signal Source, how to do Doppler simulations with the Doppler Correction block and data from Astropy or HORIZONS, and how to measure frequency very accurately by using a PLL to measure phase.
Session 5. beamforming. Shows how beamforming works by aligning the phase and delay of the signals from multiple antennas. A demo of a linear array is done to show how beam steering works, and its relationship with interferometric imaging.
Session 6. Hydrogen_line. Hands-on activity during the visit to the Allen Telescope Array. Measurement of the Doppler spectra of the galactic HI line.