USDA UV-B Monitoring System: An Application of Centralized Architecture

In order to monitor the spatial and temporal variations of solar ultraviolet-B (UV-B) radiation reaching the Earth surface, US Department of Agriculture (USDA) UV-B monitoring system has been developed to make ground-based measurements of UV-B radiation, photosynthetically active radiation (PAR), and temperature as well as to provide essential information to the research community, decision makers, and the public. This data collection and processing system was designed as a centralized system with a star network topology covering the domain of the United States with two sites in Canada and one in New Zealand. The system is controlled by a central data server and measurements are collected through programmed data loggers. While a centralized architecture has the single failure problem, it makes the system less complex to build, implement, and maintain. In this paper, we present the system architecture, algorithms for data collection, and data flow in the data processing procedures. Samples of our measurements and products are also shown. This work shows the principle application of centralized architecture in distributed computing and is a good reference for designers of similar systems.