Within the EPOS-PL project (POIR.04.02.00-14-A003/16) two microwave radiometers RPG-HATPRO-G5, supplied by Radiometer Physics GmbH, were purchased. The instruments were installed on the building of the Faculty of Environmental Engineering and Geodesy of the Wrocław University of Environmental and Life Sciences and in the Geodetic-Geophysical Observatory Borowa Góra. RPG-HATPRO series develops microwave radiometers designed for continuous measurement of temperature and humidity profiles in the troposphere, parallely in several selected frequency channels.
Radiometers enable continuous monitoring of troposphere condition with one-second frequency of recording parameters. The use of infrared radiometer, which is a module of the instrument, allows to detect clouds and to measure the height of the base of clouds. Radiometers are also equipped with Vaisala meteorological stations (WXT530) that allow to conduct surface measurement of pressure, temperature, relative humidity, wind speed, wind direction and rainfall. In addition to the temperature and humidity profiles, the instruments measure integrated quantities such as the Integrated Water Vapour (IWV) and the Liquid Water Path (LWP).
In the context of research conducted in the Institute of Geodesy and Geoinformatics, one of the most important functions of the acquired equipment is detection of microwave signal delays in the troposphere in the zenith direction. Moreover, one of the purchased radiometers (located in Wrocław) has been equipped with an azimuthal positioner with a controller that enable to scan the sky for given vertical angles. The combination of these modules will allow to determine the microwave signal delay due to the presence of water vapour in the troposphere for all GNSS satellites visible above the horizon, on the direction to the satellite. The data from the instrument will serve as a reference data source for the NRT system for the determination of zenith tropospheric delays developed within the EPOS-PL project. Moreover, the measurements of slant tropospheric delay will expand the set of observations of the tomographic model TOMO2 developed at the Institute.
The instrument software provides access to data at all levels: raw measurement data, calibrated brightness temperatures and atmospheric products, which in the future will supply the resources of national scientific consortia, such as the Aerosol Research Network Poland-AOD.
Fig. 1. Microwave radiometer RPG-HATPRO-G5 in the Geodetic-Geophysical Observatory Borowa Góra
Fig. 2. Profiles of absolute humidity, temperature and liquid water path registered by the microwave radiometer RPG-HATPRO-G5 in the Institute of Geodesy and Geoinformatics at the Wrocław University of Environmental and Life Sciences