Three Bearing Method for Passive Triangulation in Systems with Unknown Deterministic Biases

An operationally simple method for triangulation in systems with strong biases is presented. The method requires three bearing measurements and two turns by the aircraft. Analysis of the method shows that accurate triangulation can be performed without knowing the bias function. The method has been tested by numerical simulation and in actual flights, and the test results are reported. An approximate method for including small random fluctuations and confidence contours about the point of triangulation is given.