The data logger is programmed to collect the data from each sensor every second and the data are summarized at 15- minute intervals. At midnight, the daily totals as well as daily maximum, minimum and average values are calculated. Communication with these weather stations is critical. Each station has a dedicated telephone line and modem to download the weather data. In our laboratory in Griffin, we maintain several personal computers that operate 24 hours per day, seven days per week, to download and process the weather data from the weather stations.
All processing is done automatically without any human interaction.
The computer is programmed to call all weather stations once a day at midnight. It downloads the weather data collected for the previous day, especially the daily total rainfall and maximum and minimum temperature. For more than 20 sites, the current weather conditions are downloaded at least once an hour and made available via the World Wide Web. Although all data processing is done automatically, it involves many different steps. After the weather data have been received by our personal computer, the quality of the data is checked.