Sunday, 11 January 2009
A stereoscopic cloud top height retrieval technique from combined geostationary and low earth orbiting satellites
Phoenix Convention Center
Cloud Top Height (CTH) is an important atmospheric parameter which may be used to conduct cloud classification, assign height levels to GOES cloud drift winds, or estimate tropical cyclone intensity. A stereoscopic CTH retrieval technique has been developed which combines data from a geostationary and a low earth polar orbiting satellite. Geostationary observations from the GOES I-M sensor are used in conjunction with measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument to obtain distinct viewing angles of cloud features. The parallax shift of cloud position relative to the surface of the Earth is used to determine cloud height. Cloud velocity is calculated from GOES I-M data and used to correct for cloud motion. A comparison with stereoscopic CTH data from the Multiangle Imaging Spectroradiometer (MISR) produced a mean height difference of –0.21 km relative to MISR and a standard deviation of 2.17 km with a sample size of 805. Conducting a two-sided t-test, the mean difference is not statistically different from 0 at the 99% confidence level. Overall results indicate the algorithm performs well compared to MISR.