Institute of Meteorology and Climate Research

The Microwave Radiometer 5 (MIRA5)

A new ground-based 22 GHz water vapour radiometer is currently in development at IMK Karlsruhe. In a first stage the instrument was equipped with an Acousto-Optical-Spectrometer (AOS), but in the course of the year a high-resolution digital Fourier spectrometer will be integrated in the system. It's planned to retrieve tropospheric, stratospheric, as well as mesospheric water vapour from the spectra measured by MIRA 5.

MIRA5 in our lab

Here is the new 22 GHz water vapour radiometer MIRA 5 in the laboratory at IMK-ASF.
The dewar containing the cold calibration load can be seen in the foreground, on top is the thermally stabilised warm calibration load.

water vapour spectrum

A water vapour spectrum of 18th May 2008 as measured by MIRA 5 at IMK Karlsruhe.
The tropospheric base as well as the stratospheric signature at 22.235 GHz can be seen. An Acousto Optical Spectrometer (AOS) was used for this measurement.