COMPARISON OF GROUND TECHNIQUES USED TO ESTIMATE CLOUD COVER

Cloud cover is a key feature in Earth images acquired from space. Cloud cover data play a significant role in the weather forecast and climate knowledge, as well as in several human activities. Several studies have been conducted to establish a methodology and experimental setup in order to acquire reliable cloud cover data from remote sense observations performed on the surface. This research aimed at comparing ground data acquired by different systems for the same atmospheric scenario regarding cloud cover. Solar radiation data and sky images acquired at SONDA station located in Florianin 2002, were used to evaluate cloud cover. Also, cloud cover data collected at the international airport meteorological station distant 7,700 m from the SONDA station were used. This work compares these two sets of data acquired for sky scenarios with only one type of cloud. The results show good agreement in clear and completely overcast sky conditions. Future studies using longer time series will be developed in order to evaluate the influence of seasonal variability and atmospheric scenarios with several cloud types (low, medium and high