Hyperspectral Infrared Atmospheric Sounder (HIRAS) Atmospheric Sounding System

Accurate atmospheric temperature and moisture profiles are essential for weather forecasts research. Satellite-based hyperspectral infrared observations meaningful in detecting profiles, especially over oceans where conventional can seldom be used. In this study, a HIRAS (Hyperspectral Infrared Atmospheric Sounder) Sounding System (HASS) was introduced, which retrieves using one-dimension variational scheme based on observations. A total of 274 channels were optimally selected from the entire spectrum through information entropy analyses, group retrieval experiments independently performed different fields views (FOVs). Compared with ECMWF reanalysis data version-5 (ERA5), RMSEs (relative humidity) low-, mid-, high-troposphere layers 1.5 K (22.3%), 1.0 (33.2%), 1.3 (38.5%), respectively, similar magnitude to those derived other sounders. Meanwhile, retrieved respect satellite radio occultation (RO) products increased 1.7 K, 1.8 1.9 layers, could attributed accurate RO upper atmospheres. It also found that RMSE varied FOVs latitude, may caused by current angle-dependent bias correction unique background profiles.