The horizontal velocity at the outermost edge and thickness of bubbly flow are measured by laser Doppler velocity technique.

To meet the seism detections require of high accuracy, high resolving power, the measurement technique of Laser Doppler and detection technique of faint signal are further researched.

Feasibility is discussed that a multi-longitudinal mode laser is employed as the detection light source of the double-edge technique for Doppler lidar wind measurement.