You're missing a key piece of the understanding of the KrakenSDR information. Unlike legacy RDF systems that use a single antenna and radio to find only the direction of the emitter, the Kraken has multiple antennas and radios working together with a microprocessor. Those elements allow not only finding the direction, but also the DISTANCE to the emitter via DTOA (Differential Time Of Arrival) of the signal. That allows a single Kraken unit to quite accurately locate an emitter. If you have more than one Kraken unit (as in legacy RDF) then the accuracy is even greater. That is how a single Kraken located an emitter in 84 seconds.
Errr...no.
The Kraken does not calculate distance by DTOA (or TDOA, or multilateration).
The Kraken measures the phase of arrival of a signal on each antenna element. Knowing the phase on each element, and having the element configuration and size as an input value (and so element spacing), it can then calculate angle or direction of arrival (DOA) from that phase. Of course, it can be argued that phase is time, and so the Kraken does determine (if not measure) DTOA, but the important part is not what it is measuring, but rather what it is calculating via that measurement. It calculates direction of arrival, not distance.
The base, the distance between elements, is too small to measure distance via TDOA at any meaningful distance.
If the Kraken never moves that is all you get, angle or direction of arrival. But if the Kraken moves you now create a synthetic aperture. At location A the Kraken has a DOA. The software plots that DOA on a map (or in 2D space). A few seconds later, at location B, it takes another DOA, since the platform is in motion this results in different DOA, and the cuts intersect someplace. A few seconds later, at location C, it takes another, and another, etc.
Each of these cuts is from a different location (the platform is in motion, yes?) It is like having multiple RDF sources reporting direction cuts.
The software then continually calculates the intersection point of each of the cuts, refining the location of the emitter. To the best of my knowledge, it only does this when using the App, and having access to the GPS location of the device the App is on. If it can do this from another GPS source I have not figured out how yet.
The first thing I did with my Krakken was to find out who it was in my neighborhood that had the temperature sensors pinging on 434 MHz. The second thing was to track down a jammer hitting a local GMRS freq. Slick, easy, and relatively accurate with minimal effort.
T!