ABSTRACT

This study analyzed a time series data on solar radiation. The data for this analysis was international Institute of Tropical Agriculture (IlTA), Humid Forest Station, Onne Port Harcourt, Rivers State and covered the period 1996--- 1997. The ultimate objective of this study was to construct a mathematical model, which could be used to forecast a reliable and relevant future solar radiation pattern for Onne Port Harcourt. Simple descriptive time series analysis was used to estimate and consequently isolate the components (trend, seasonal, cyclical and irregular) of the time series data based on the original data. The analysis showed that the trend was constait and so it was estimated using the overall mean. Seasonal variations were found to be present in the data. This seasonal variation were estimated and isolated leaving behind the residuals. Forecasts of future solar radiation pattern were made using the estimates of the trend and seasonal variations. It is recommended that data for prolonged period say twenty years be used a probability model be fitted to the data for better forecast.