Tropical Cyclone Cloud Height Calculations from Stereoscopic Satellite Imagery

Accurate cloud height measurements are vital for understanding a variety of meteorological phenomena, including extreme weather events such as overshooting cloud tops and tropical cyclone intensity. Standard cloud height calculations based on infrared brightness temperatures compared to vertical atmospheric temperatures are subject to error. This error derives largely from the accuracy of the vertical temperature profile and the number of levels a particular temperature can occur. Stereoscopic comparison of visible imagery from two satellites reduces the error for two reasons. First, visible imagery has a pixel resolution greater than infrared. Second, the geolocation of cloud pixels for both satellites can be calculated precisely using the spacecraft positions rather than comparing brightness temperatures to atmospheric temperatures at multiple levels. This technique is tested on tropical cyclones in order to gain a better understanding of their development, intensity, and structure. Visible satellite data from GOES East and GOES West were analyzed and the resulting images cloud heights were calculated based on satellite positions and image scan vectors. The methods for calculating cloud height and matching pixels between the two data sets are described. Examples of stereoscopic images and cloud height analyses of Atlantic and Pacific tropical storms and hurricanes are also shown.