Analysis Of Attenuation For Millimeter Wave Propagation In Atmosphere

Since the millimeter-wave radar has a broad development space and broadapplication prospects in meteorology, remote sensing, detection and guidance and othercivil and military fields, the study of the millimeter wave propagation attenuation inatmosphere become a key issue for the development of millimeter-wave radar. Themillimeter-wave attenuation caused by the absorption of atmosphere, cloud, rain anddust are studied, the main content and the results are as fllows:Based on the atmospheric absorption model recommended by the ITU-R at thehorizontal path and slant path, the atmospheric absorption at millimeter wave band iscalculated. The results show that in horizontal path oxygen absorption peak is at afrequency of60GHz, and in slant path the atmospheric attenuation decreases as theelevation angle increases, increases as the frequency increases.The cloud attenuation at millimeter wave band is calculated on the vertical pathand slant path. The results show that the cloud attenuation relate with the water contentand the frequency. The greater the water content and the frequency, the greater the cloudattenuation.Based on the rain attenuation prediction model recommended by the ITU-R, therain attenuation at millimeter wave band is calculated. The results show that thefrequency and the rainfall rate have a strong impact on the rain attenuation. The rainfallrate is an important factor for the millimeter wave propagation in atmosphere.The attenuation in explosion sand-dust, dust chariots and natural sand-dust arecalculated. The attenuation increases with the increase of frequency and moisturecontent.This results are significant for the millimeter wave radar development andapplication.