Table 3 Parameters used for simulation.

Background count rate

\(8 \times 10^{-6}\)

Error correction efficiency f

1.15

Detector efficiency

14.5%

Aperture diameter, D

\(15 \times 10^{-2}\) m

\(C_{n}^{2}\)

\(10^{-14} \text {m}^{-2/3}\)

Wavelength of the beam, \(\lambda\)

1550 nm

Terminal velocity of rain, \(v\,(D_{\text {rain}})\)

9 m/s

Rain-drop size distribution , \(n\,(D_{\text {rain}})\)

\(10^{5}\)

Percentage rain volume, \(m\,(D_{\text {rain}})\)

1

Number of particles per unit volume, \(N_{\text {fog}}\)

\(10^{15}\)