A collection of Jupyter notebooks to explore the transmission and reception of the FT8 digital mode.
FT8 is a digital mode used by amateur radio operators that has become quite popular since it was first introduced in 2017. It was created by Dr. Joe Taylor (K1JT) and Dr. Steven Franke (K9AN) and their collaborators who develop the WSJT-X program.
I was interested in how FT8 works, so I decided to read the source code of WSJT-X and document what I learned in a series of Jupyter notebooks, as there is no formal specification for FT8. As part of this process I have re-implemented most of the FT8 protocols used by WSJT-X in a Python module called ft8.
The main notebooks in this repository are:
- Background - Background material to level set an audience prior to diving into how FT8 works.
- Transmit - A walkthrough of how FT8 signals are transmitted.
- Receive - A walkthrough of how FT8 signals are received.
The github renderer for Jupyter notebooks has some limitations that I haven't been able to work around. Therefore, it is best to view notebooks via nbviewer. This repository can be accessed through nbviewer here.
Each of the main notebooks includes the additional metadata required to enable the notebooks to be presented using the presentation mode of nbviewer.
The remaining notebooks focus on narrow aspects of FT8 and do not include any presentation metadata.
This repository is a work in progress and does not yet fully implement all the features of the FT8 implementation in WSJT-X. There are also some aspects of the WSJT-X FT8 implementation that I do not yet fully understand.
These notebooks are based on reviewing the source code of WSJT-X. I thank Dr. Joe Taylor and his collaborators for open sourcing WSJT-X to enable others to study the code and learn from it.
The code is this repository uses similar algorithms to those used in WSJT-X in many instances. However, in some instances the algorithms have been modified significantly to enable better performance in the Python programming language.
There are a few other repositories on Github that may be of interest:
- rtmrtmrtmrtm/basicft8 is a basic Python implementation of a FT8 receiver. Note that it has not been updated to reflect changes to the FT8 protocol that were made in 2018 so it will not work with the signals generated by the current version of WSJT-X.
- rtmrtmrtmrtm/weakmon is a very comprehensive set of Python scripts that explore FT8 and other weak signal digital modes.
- kgoba/ft8_lib is a C++ library intended for use with microcontrollers.
Copyright (C) 2019 James Kelly, VK3JPK
The ft8 Python module in this repository is licensed under the GNU General Public License Version 3.0.
All other materials are licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.