The measure of the light signal from the intensifier tube of the night vision devices is incident on the human eye, which is further divided by means of the perceived noise named as SNR that is visible to the naked eyes.
The SNR over the intensifier tube shows the low light resolution of the image on the tube. This formation increases the value of the signal to noise ratio, which makes the ability of the intensifier tube greater to that of the resolving objects with good contrast even in the low light condition.
The signal to noise ratio is directly related to the sensitivity range of the photocathode, to improve the efficiency of the phosphor screen and to perform the image intensification operation. The SNR is one of the single and favorable factors to estimate the overall system ability to view the imaging in the complete dark situations.