Cloud detection and height from GOES.

摘要

The Bi-spectral Threshold and Height (BTH) method is introduced as a technique for twenty-four hour cloud detection and height assignment from the Geostationary Operational Environmental Satellite-8 Imager and Sounder instruments. The BTH cloud algorithm utilizes 3.9 and 10.7 mum differencing thresholds and twenty-day composite imagery for cloud detection. A quantitative comparison for three two-week case studies shows that the BTH technique significantly improves diurnal cloud detection over the previous Bi-spectral Spatial Coherence method by 53% during the nighttime, 36% at sunrise, and 60% at sunset. The daytime hours showed the smallest improvement in cloud detection by 5%. Other comparisons between similar cloud products show the National Environmental Satellite, Data, and Information Service technique detects 6% more clouds than the BTH method, but over determines 37% of the clear pixels. The BTH cloud pressure product is 135 mb higher on average, when compared to the University of Wisconsin-Madison technique.