Table of Contents
Cloud Radar JOYRAD-35
Mentor: K. Ebell, S. Kneifel
Principle
The cloud radar JOYRAD-35 is a Doppler radar that transmits a linear polarized signal at 35.5 GHz and receives co- and cross-polarized signals simultaneously. In this way, vertical profiles of reflectivity, Doppler velocity, Doppler spectral width and of linear depolarization ratio are detected from 150 m to 15 km above ground. Given these measurements, information on the macrophysical (cloud boundaries, type of cloud particles) and microphysical (e.g., liquid and ice water content) properties of the detected cloud can be derived. The radar can be operated in a vertically pointing mode but also has scanning capabilities in order to better capture the 3-dimensional structure of the cloud.
Instrument
MIRA36-S (Metek) at Forschungszentrum Jülich on the roof of the IEK-8 (Institut für Energie- und Klimaforschung: Troposphäre).
Data
- If you are interested in receiving data please contact the instrument mentors: S. Kneifel, K. Ebell
Current measurements:
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<a href="http://atmos.meteo.uni-koeln.de/~hatpro/jue/VAPs/radar_mwr/latest_l2_radar_lwp.png" target="_blank"> <img src="http://atmos.meteo.uni-koeln.de/~hatpro/jue/VAPs/radar_mwr/latest_l2_radar_lwp.png" width=500> </a> click to enlarge
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The figure shows the LWP from the HATPRO MWR as well as radar reflectivity factor, linear depolarization ratio, Doppler velocity and Doppler spectral width of MIRA zenith measurements.
Gray areas indicate no data.
History
Period | Place | Project |
---|---|---|
09/03/2012 - today | Research Center Jülich, Germany | JOYCE |
08/11/2011 - 08/03/2012 | Munich Airport, Germany | iPort campaign |
03/2011 - 07/11/2011 | Research Center Jülich, Germany | JOYCE |
Specifications
Parameter | Specification | Remark |
---|---|---|
Frequency | 35.5 ± 0.15 GHz | corresponds to wavelength of 8.5 mm |
Peak power (max) | 25 kW | |
Average power | ~ 24 W | |
Pulse width | 200 ns | adjustable (100, 200, or 400 ns) |
Pulse repetition frequency | 5 kHz | adjustable (5-10 kHz) |
Minimum height | 150 m | full sensitivity above 400 m |
Measuring range | 15 km | adjustable (7.5-30 km) |
Range resolution | 30 m | adjustable (15, 30, or 60 m) |
Antenna beam width | 0.6° | |
Doppler velocity resolution | 0.025 m/s | depends on FFT length |
Maximum unambiguous velocity | ±20 m/s | |
Maximum sensitivity at 5 km (integration 0.1 s) | -45 dBZ | |
Calibration system accuracy | ±0.5 dB | |
Number of gates (with simultaneous stored raw data) | 500 | |
Number of averaging spectra | 200 | adjustable (1-32768) |
Manufacturer | Metek |