Abstract

The measurement error depends on a great deal of factors when measuring the average frequency of the Doppler Lidar. One of the main factors is the turbulent wind velocity fluctuations. The existence of these fluctuations is the cause that the particles occurring in a scattering volume have different fluctuation velocities. Moreover, the positions of the particles within the scattering volume are random. Therefore, the photocurrent statistical characteristics of the Doppler Lidar and, consequently, the measurement error depend on the state of the turbulent atmosphere and dimensions of the scattering volume. For example, the statistical characteristics of the photocurrent signal part are the non-Gaussian ones in the case of small value of the dimensions of the scattering volume and the statistical characteristics can be considered the Gaussian ones in the case of large value of the dimensions of the scattering volume. Thus the usual methods of the estimate of the measurement accuracy of the average Doppler frequency based on the assumption of the Gaussian statistics of the photocurrent signal part (see Ref. ¹) have a limited application area. The behavior of the measurement error of the average frequency of the pulsed and cw- Doppler Lidar as a function of parameters of the turbulent atmosphere and the dimensions of the scattering volume is studied for the autocorrelation function method. The consideration is based on the results of Ref. ² in which the non-Gaussian random process is analyzed.

© 1995 Optical Society of America