Under the condition of formation flying

the relation between InSAR phase characteristic and flat earth

was deduced as well as the relation between phase characteristic and terrain height.The influence of flat earth and terrain height to phase was thoroughly analyzed.Flat earth and terrain height have common effect on InSAR phase.Thus the phase can be written in the form of sum of 2 partial derivatives.An example of cone was given as simulated real terrain.Simulation of different look angle

different radar wavelength and different baseline length was performed.The simulated result was in accordance with theoretical analysis result.