KrakenRF
The KrakenSDR is a coherent software defined radio. Coherence allows very interesting applications such as radio direction finding and beamforming The most common application of the KrakenSDR is radio direction finding. Radio Direction Finding (RDF) refers to any technique used to determine the direction towards a radio frequency transmitter. The simplest method is to use an antenna that only receives signals from the direction it is pointed, and then manually sweep through 360 degrees to identify the azimuth that receives the strongest signal. You can then do this from multiple locations and note where the bearings intersect. Unfortunately, this "simple" method requires a tuned directional antenna and a manual, error-prone process. There are other techniques such as Pseudo-Doppler and Watson-Watt. However, because the KrakenSDR is a coherent SDR, we are able to use a more advanced technique called Correlation Interferometry, which exploits the phase information found in an array of antennas that are spaced apart in some known pattern. Running this information through an algorithm like MUSIC produces a bearing in the direction of the emitter. By taking multiple bearing readings at different locations, we are able to triangulate the position of the transmitter.