This has been a really fun project to work on during the weekends, definitely recommend it. Next step for me will be to get automatic direction finding working, hopefully will finish that during the next year.
Are you using multiple phase matched receivers? I've wanted to try that on P.25 radios here in the US but never gotten the hardware, time, and motivation together. :)
I'm way out of my depth with the ADF. A friend gave me an old rotating marine ADF receiver I've been playing with, but as it turns out I'm not gonna get that spinning fast enough for my purposes.
I've got the mathematics background to eventually get this working, but not the radio background to do so very quickly.
There are UK companies with a similar commercial products https://www.targetblueye.co.uk https://www.pythondetectors.com