Propagation Characteristics of Infrared Pulse Waves through Windblown Sand and Dust Atmosphere

Abstract

The physics characteristics of the windblown sand and dust atmosphere at the sand bench of Yellow River in China are discussed. The pulse distortion and time delay of infrared nanosecond pulse propagating through the atmosphere having sand and dust particles are investigated at 1.06 and 3.8 μm, respectively. It is shown that the delay of 10 ns laser pulse propagating through 5 km windblown sand and dust atmosphere are over 1 ns and 10 ns at 1.06 and 3.8 μm, respectively. The pulse spread increases slightly with wavelength increase. The pulse spread of a 10 ns laser pulse is over 40 ns at 3.8 μm. The pulse delay and spread increase rapidly with the sand particle density increasing in atmosphere. The narrower the pulse width is, the more the pulse distortion is. Hence, at infrared band, for a laser pulse propagating in sand and dust atmosphere, the pulse delay and spread are quite severe and need be taken into account for a narrower pulse laser system.

A Computationally Efficient Numerical Simulation for Generating Atmospheric Optical Scintillations

“…As discussed in (Fante, 1975;Ishimaru, 1997;Kennedy, 1968), dispersion and beam spreading due to turbulent atmosphere can be neglected. Only for the very short pulses less than 100 ps proposed for high-data rate communications systems, or in extreme scenarios such as the one detailed in (Ruike et al, 2007), where sand and dust particles are likely present, pulse spreading owing to turbulent atmosphere must be included. For this latter case, physically, two possible causes exist for this pulse spreading: scattering (dispersion) and pulse wander (fluctuations in arrival time), although it is found that, under the condition of weak scattering, pulse wandering dominates the contribution to the overall broadening of the pulse Young et al, 1998).…”

Propagating Characteristics of Pulsed Laser in Rain

“…Laser detection becomes more and more important in remote measurement, for its highly monochromatic and coherent, high energy density and fine time resolution [1]. Meanwhile, it is also well known that light propagating in atmosphere is highly scattered by atmospheric hydrometeors and aerosols, occasionally causing an extreme high attenuation of the received power [2][3][4][5][6].…”