[colanderman]

https://khanfar-spectrum-analyzer.web.app/ also has some phase-based direction-finding software and upcoming hardware.

For triangulation though, if you have a reference signal at a known location, TDoA (time difference of arrival) requires less hardware (just a single receiver at each location, e.g. an RTL-SDR). I don't know of any open-source software which does that though I've been slowly building some for my own use (it's pretty janky at the moment).

[advy]

You could perhaps compare notes with the author of [0] who did manage to achieve multilateration with rtl-sdrs using TDoA.

[0] https://jenda.hrach.eu/

[colanderman]

Oh wow that's a fantastic resource thank you!

[ortusdux]

I want to experiment with stationary receivers around the perimeter of my property. It would be fun to document and pinpoint every RF source on my land, but I'd settle for being able to reliably find my dog.

[colanderman]

Ah TDoA might not have the resolution you need for that, unless you are working with very wideband signals. Probably ~100 m resolution is the best you can get from it.