Terrestrial radio link is challenged by clear air environmental factors like multipath fading, diffraction fadingrnand atmospheric gaseous losses. These radio link impairments need to be discovered using right meteorologicalrnparameters and applying appropriate models so that its result will be used in design of terrestrialrnradio link of line-of-sight communications. Ethiopia and other countries found in tropical regions are relyingrnon ITU-R database for designing of terrestrial line-of-sight link communication which could end up to overrnprediction or under prediction of impairments. ITU-R data source was initially prepared from climates ofrncountries located in Temperate region that might not fit for a tropical region.rnThe investigation of finding clear-air radioclimatic parameters for the terrestrial radio-link requires intensiverndata collection from local meteorological sources. The input parameters to design radio link thatrncomes from investigation depend on local data is expected to be more reliable when it compares to the ITU-Rrndatabase. Most researchers have used their local data to investigate secondary radioclimatic parameters,rnthat are used as inputs for the design of terrestrial radio-link. But, the meteorological data are limited torntheir local weather condition, that may not be applied at different geographic locations.rnThis thesis has utilized five to ten years, 15 minutes intervals, surface data of temperature and humidityrnwith one year daily data of Radiosonde were collected from the National Meteorological Agency of Ethiopia.rnSatelliteâ€™s monthly pressure data of "FLDAS Noah Land Surface Model L4 Global" was used and integratedrnusing the Haversine formula with surface data from the meteorological agency to have full information aboutrntemperature, pressure, and humidity of selected 58 geographical places in Ethiopia. The Radiosonde datarnwere used for developing a new vertical atmospheric profile model in Addis Ababa. The secondary parameterrnof the modeled atmospheric profile result was compared with the result of the ITU-R law latitude modelrnand with the ITU-R database. MAE and RMSE are used as the error comparison between the results ofrnthe ITU-R results and the proposed model. The performance of the proposed models is found to be betterrncompared to the other models. ArcMap, ExceLab, Ms-Excel, and Python programming are the tools thatrnare used to analyze and demonstrate results in graphs, charts, and maps.rnThis thesis work produces results from the investigation of refractivity, point refractivity gradient, geoclimaticrnfactor K, and k-factor at the selected locations in Ethiopia. The distribution of each parameterrnis presented in monthly, seasonal, and average year time. The curve fitting approximated for the k-factorrndistribution is Gaussian normal distribution and the corresponding Integral Square Error approach is usedrnfor error checking. The maps and databases are generated using Ordinary-kriging with ArcGIS softwarerntool. The resulting database can be used for consumption by radio link designers.