Noise cancellation - CL61

CL61 User Guide

Document code
M212475EN
Revision
D
Language
English (United States)
Product
CL61
Document type
User guide

The transmitted laser power is set so that the noise of the ambient light exceeds the backscattered signal. To overcome this, a large number of laser pulses are sent, and the returns are summed. During this process the noise, being random, partially cancels itself. The degree of cancellation for white (Gaussian) noise equals the square root of the number of samples; thus, the resulting signal-to-noise ratio improvement is equal to the square root of the number of samples. However, this processing gain cannot be extended endlessly since the environment changes and, for example, clouds move.