Ka-band propagation studies using the ACTS propagation terminal and the CSU-chill multiparameter radar

Propagation through the atmosphere is studied utilizing satellite data along with radar based propagation models. In September 1993, the National Aeronautics and Space Administration's (NASA) Advanced Communications Technology Satellite (ACTS) was deployed into geostationary orbit, near 100;In order to gain more understanding about the physical processes that are responsible for Ka-band attentuation, the CSU-CHILL polarimetric radar is used to take radar measurements along the slant path. The Colorado Front Range experiences a variety of weather conditions throughout the year, ranging from upslope rain conditions to winter storms. Four such events measured along the slant path are illustrated here. They include two "bright band" cases, a weak convective case, and a strong convective case where the 27 GHz attentuation exceeded 30 dB. The S-band polarimetric radar data is used to initialize two newly developed radar driven propagation models. One is a propagation model that incorporates the Mueller and extinction matrices, while the other uses a simpler approach, namely, a power function law to relate S-band reflectivity to Ka-band attentuation. Results using the S-band reflectivity/Ka-band attentuation relationship for concurrent CSU-APT and CSU-CHILL measurements of the four events mentioned above are presented. A case study using the Mueller propagation model is also presented along with discussions of future applications.