A Kalman filter approach for microwave radiometric profiling of the Antarctic atmosphere

The retrieval of atmospheric parameters such as temperature profiles and columnar water vapor and liquid, or their profiles, can be obtained continuously and automatically in nearly all weather conditions by using microwave radiometers; they are particularly suitable for the development of profiling systems to be installed in hostile environments. Within the framework of the National Program of Researches in Antarctica the authors have already defined the specifications of the radiometric channels, in terms of optimum number, frequencies and sensitivities, of a ground-based temperature profiler [Basili et al., 1994]. In the present paper the authors have assumed the availability of measurements of pressure, temperature and relative humidity at the surface, of two water (vapor and liquid) sensing channels at 23.8 and 36.5 GHz and the temperature sensing radiometric channels selected in a previous analysis along the 60 GHz O₂ absorption complex [Basili et al.]. The authors have also considered the addition of the atmospheric sensing channels of SSM/T and/or MSU. On the basis of these measurements and radiosounding data for the Antarctic atmosphere the authors have developed a Kalman filtering algorithm, suitable for the foreseen operational mode of a continuously working profiler