This is an old revision of the document!
Table of Contents
Instruments operated by RG Integrated Remote Sensing
The Atmospheric Emitted Radiance Interferometer (AERI) measures downwelling infrared radiation from 3-25 µm at less than one wavenumber resolution to derive profiles of tropospheric temperature and humidity. It is also sensitive cloud properties and CO2.
Our ceilometer CT25K is based on the light detecting and ranging (LIDAR) principle: it sends out laser pulses and measures the backscattered light (at 905 nm). From the time delay it derives cloud base height (i.e. the ceiling in aviation) up 7.5 km hieght as well as boundary layer structures. We also operate a high-power ceilometer CHM15k which can detect clouds up to 15 km height. For background information see the EG-CLIMET wiki.
Our scanning cloud radar JOYRAD-35 is a pulsed Doppler radar which measures profiles of reflectivity, Doppler velocity, Doppler spectral width, and linear depolarization ratio at 35.5 GHz. From these, various macro- and microphysical properties of clouds and precipitation can be derived. In addition, we operate the 94 GHz FMCW cloud radar cloud radar JOYRAD-94 which can resolve cloud structures down to a resolution of 5 m. For background information see the EG-CLIMET wiki.
The Doppler Lidar sends out pulses of light in the near-infrared part of the spectrum. The Doppler shift of the signal backscattered by aerosol can be used to infer line-of-sight wind speed within the boundary layer. Scanning in elevation and azimuth allows derivation of the full wind vector. For background information see the EG-CLIMET wiki.
Forschungszentrum Jülich operates as 120 m high meteorological tower with platforms for measuring wind, humidity and temperature.
Microwave radiometers measure spectral radiance emitted and scattered by atmospheric gases and hydrometeors. Our reserach group operates three Humidity And Temperature PROfilers (HATPRO) which are suited for continuously monitoring the hemispheric distribution of cloud Liquid Water Path (LWP) and Integrated Water Vapor (IWV) as well as tropospheric temperature profiles.
Additionally, a Dual Polarization Radiometer (DPR) is operated which measures in mm wavelength atmospheric windows and is highly sensitive to snowfall and super-cooled liquid water. Click here for a list of relevant references. For background information see the EG-CLIMET wiki.
The Micro Rain Radar (MRR) is a vertically pointing FMCW Doppler radar operating in the K-band. From the Doppler spectra the radar reflectivity factor (Ze) and the terminal fall velocity distribution as well as microphysical rain properties can be derived.
Multi-Filter Rotating Shadowband Radiometer
The Multi-Filter Rotating Shadowband Radiometer (MFRSR) allows the retrieval of aerosol optical depth, aerosol size information as well as cloud optical depth for single-layer “horizontally homogeneous” liquid clouds.
A complete surface radiation balance is possible with the radiation sensors measuring at JOYCE.
Surface precipitation is measured with a standard Pluvio gauge (weighing principle) as well as with an optical didrometer Parsivel yielding information on the size and fall velocity of the precipitation particles.
A Scintillometer measures the path-averaged structure parameter of the refractive index of air over horizontal path. In combination with standart meteorological observations (air temperature, wind speed, and air pressure) this can be used to derive the surface sensible heat flux.
A SODAR is a wind profiler based on the SOnic Detecting And Ranging principle. A sound is emitted and backscattered at inhomogeneities of the temperature field. Travel time of the backscattered sound signal is related to distance, Doppler shift gives the wind speed along the sound beam. Several tilted sound beams allow to infer the vector components of the wind.
Our Total Sky Imager (TSI) is used to identify cloud types and derives cloud coverage complementing the observations of the other instruments.