Thanks for all the responses - yes its the tech-behind-the-blurb that I’m interested in.
I thought perhaps a couple of crossed ferrites might be the answer but couldn’t see how the kind of directional accuracy being implied was possible with a setup of that sort - any of you familiar with older ship’s navigation equipment might remember MF RDF - not exactly an accurate position fixing technology! Hence I suspected there might be something else going on.
From the blurb the following facts are clear
(i) the antenna is active (hence the heat methinks)
(ii) distance is derived from signal strength
Whatever about directional accuracy (which I have suspicions about) the distance can’t be terribly accurate - propagation, local interference, etc. will see to that.
I note with interest that the professionals use multiple direction finding stations and triangulate to achieve an approximate position for a strike, thereby eliminating the need to determine distance using other means. I wonder if Boltek could do this by linking customers via their software & the web…