Technology of passive location has broad prospects in applications.In this paper

the method using phase difference rate of change for single observer-passive location is introduced based on existing methods.We can obtain the direction of the target with phase difference information of two orthogonal interferometers on the observer and the radial distance with corresponding phase difference rate of change.Then the target can be located with high speed and precision.When flying posture of the observer is changed

the target can be located in the new coordinate system according to measurement data.And its position in the original coordinate system can be obtained through the rotating matrix between two coordinate systems.Related locating expressions are given.Simulations show that this method is effective.