Dual-Satellite Stereoscopic Retrieval of Cloud Top Height Using FY-4A and FY-4B

We developed a dual-satellite stereoscopic cloud top height (CTH) retrieval algorithm based on the visible band (0.65 μm) data of FY-4A and FY-4B. This algorithm offers an extensive longitude coverage from 55°E to 177°W. The analysis of system error based on error theory shows that the CTH we retrieved has an accuracy of 0.20–0.88 km and an uncertainty of 0.24–1.08 km over the entire area. The space resolution of the CTH we retrieved reached less than 0.005°. We conducted a CTH retrieval experiment and proceeded to compare our results with FY-4B’s CTH product and CALIPSO. Compared to CALIPSO, the CTH we retrieved has a bias of −2.4 km and the correlation coefficient is 0.80. In general, two next-generation geostationary satellites were used simultaneously to retrieve the CTH in our study, demonstrating the ability of this satellite combination to obtain better-quality CTH products by stereoscopic retrieval.