Measurements of tree attenuation by seasonal change of vegetation using two different elevation angle satellite for Ka-band mobile satellite communication

Abstract

NICT of Japan has performed communications propagation measurements between the WINDS and a moving vehicle earth station. Understanding the propagation environment is an important factor when constructing a communications system. NICT has been made communications propagation measurements between WINDS and the moving vehicle earth station. A shadowing has been identified as having a large impact on satellite communications due to the use of a directional Ka-band antenna with high rectilinearity in these studies. We measure the attenuation of the received signal from the satellite throughout the year with shadowing from several types of trees to capture these seasonal differences. We have already reported the results of our year-long investigation, where we observe seasonal fluctuations in the received power beneath deciduous trees but no such variations beneath evergreen trees using WINDS. We have modified the vehicle earth station so that it can capture satellites other than the WINDS satellite. The WINDS satellite was located at 143 degrees east longitude, but this target satellite is located at 110 degrees east longitude. So, we can measure at a different elevation angle than previous measurements. In this report, we explain comparison of tree attenuation measurement results from two satellites with different elevation angles.