Radio Occultation Reprocessed Climate Data Record - Multimission

This ROM SAF multi-mission data record is derived from measurements by the Radio Occultation (RO) instruments onboard the Metop, CHAMP, COSMIC and GRACE satellites in low-Earth orbit.
The RO technique utilizes the bending due to refraction of GNSS radio signals as they pass through the Earth's atmosphere. Each occultation event gives a vertical profile of atmospheric refractivity, from which temperature, pressure, and humidity are retrieved. The data have a global coverage and are insensitive to clouds and the underlying surface.
The ROM SAF multi-mission climate data record covers the time period from late 2001 to the end of 2016. The data are available as monthly means on a regular latitude-height grid. The gridded monthly means include several geophysical variables: the bending angle of the GNSS signals, atmospheric refractivity, temperature and pressure in the so called 'dry' approximation, as well as temperature and tropospheric humidity obtained by so called 1D variational retrieval(using background model data as a priori). This retrieval also include surface pressure. In addition, the ROM SAF data record include tropopause heights as gridded monthly means.
The bending angle data record constitute an FCDR, while the temperature and humidity data records constitute TCDRs of GCOS Essential Climate Variables (ECVs).