Abstract:
Interferometer can be used in the measurement of thermospheric wind velocities and there are strict requirements on the measurement system since the intensity of source (emission of airglow) is very weak. Based on the modulation property of a laser diode (LD) and high optical spectrum resolving power of Fabry-Perot Interferometer (FPI), a method to simulate wind velocity with simple equipment is discussed. Dopplers shift of airglow is simulated by changing the modulation current of LD, which leads to change in frequency of output laser. The equivalent wind velocity can be derived by analyzing interferometric images obtained by FPI. Relative errors of simulated velocities are less than 6.5%, and the least simulated velocity is 20.01m/s. The results agree with the liner modulation property of LD perfectly. This method can be applied in analysis and evaluation of the principles, data processing methods, system performance and measurement errors.