[Elecraft] Spatial Signal Filter

[David Gilbert]

Recently I described a browser-based application designed to measure and 
plot the arrival angle of a signal using the phase difference between 
two antennas spaced some distance apart, and I produced a YouTube video 
showing how multiple arrival paths and local reflections made that 
generally impossible.

However, it is a fact that every arriving signal produces its own phase 
difference, and if multiple signals arrive on the same frequency it 
should be possible to discern between them if they arrive from different 
spatial directions.  As long as they are reasonably stable spatially, of 
course.

So again using ChatGPT for the code, I created another browser-based 
application to do just that utilizing FFT processing of the stereo audio 
from two phase locked receivers.  Specifically, the application uses 
MVDR adaptive beam forming techniques with statistically derived 
variable weighting of the FFT bins associated with the various voice 
signals.  I'm not personally well informed on these techniques, but 
ChatGPT seemed to be and I'll bet K9YC and some of the other audio 
experts here know a lot more about it than I do.

In any case, although it is far from perfect, I was able to distinguish 
signals using some test files surprisingly well.

The application itself is freely available 
www.ab7e.com/SpatialSignalFilter.html

and some pre-recorded audio test files are available at 
www.ab7e.com/SpatialSignalFilter Sample Recordings.zip

A poorly done YouTube video that tries to describe and demonstrate the 
application is available at https://youtu.be/0ZaX4UZ0gqw

As usual, comments pro and con are welcome.

73,
Dave   AB7E