Comparative Analysis of Terahertz Propagation Under Dust Storm Conditions on Mars and Earth

Abstract

Reliable Terahertz (THz) links are necessary for outdoor point-to-point communication with the exponential growth of wireless data traffic. This study presents a modified Monte Carlo simulation procedure for estimating THz link attenuation due to multiple scattering by charged dust particles on the THz beam propagation path. Scattering models are developed for beams through dust, based on Mie and Rayleigh approximations for corresponding frequencies on Earth (0.24 THz) and Mars (0.24 & 1.64 THz). The simulation results are compared, considering parameters such as the number of Monte-Carlo photon (MCP) packets, visibility, dust particle placement density along the beam, frequency, and distance between the transmitter and the receiver. Moreover, a channel capacity model was proposed, considering THz link attenuation due to dust storms, spreading loss, and molecular absorption loss for Earth and Mars outdoor environments. Simulation results for Earth show that the link attenuation increases with dust particle placement density, distance, and frequency, and attenuation decreases with visibility and MCP packets. On Mars, similar results are obtained for both frequencies, except that the attenuation varies around a constant value with the frequency increase. Moreover, attenuation is slightly higher at 0.24 THz frequency compared to 1.64 THz when more dust particles are present on the beam propagation path. Channel capacity is estimated for Earth and Mars environments considering time and distance-dependent scenarios. Time windows that show a sudden drop of dust particles along the beam provide opportunities to communicate with high reliability. Moreover, increasing the distance between the transmitter and receiver severely reduces the channel capacity measurement in strong dust storm conditions in both environments. Our study has found that weak dust storms have relatively little effect on Mars but much more significant effects on Earth.