Improvement of the signal to noise ratio of Lidar echo signal based on wavelet de-noising technique

► The algorithms of wavelet transforms and wavelet de-noising are illustrated. ► The characteristics of Lidar echo signal with the noises are described. ► The steps of Lidar echo signal noise removal are demonstrated. ► Lidar echo signals taken during daytime are de-noised effectively in practice. ► Extinction coefficients of original signal and de-noised signal are compared.