The 'Doppler Shift' refers to a physics effect wherein waves emitted by a moving source are frequency shifted depending on the speed and direction of the source. Triangulation in three dimensions works by finding the unique point where all three spheres' surfaces intersect, thereby determining the 3D coordinates of the signal source. A receiver reportin that a signal is X meters away corresponds geometrically to the signal lying on a sphere of radius R, centered at the receiver. TriangulationĪfter each receiver's power reading is converted to a distance, the distances detected by all three receivers are combined with the known positions of the receivers to triangulate the signal. This requires some constant of proportionality (representing a unit conversion) to be calibrated during a controlled trial. In order for the power input from each receiver to be converted to a distance reading, the inverse-square law for power decay is used. The main routine of the app uses hard-coded, fixed positions of three sound receivers, a known signal frequency and a continuous input of decibel (logarithmic) power readings from each of the receivers.

Used triangulation, multiplexing, kalman filtering, pulse-code modulation, & fast fourier transforms to pinpoint location with a high frequency sound wave methodology.

Pinpoint doppler