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Cloud radar JOYRAD-35

JOYCE-JOYRAD35 ©B. Pospichal
Cloud radar JOYRAD-35 installed at Jülich


JOYRAD-35 is a scanning Doppler cloud radar MIRA-35 manufactured by METEK GmbH. It is installed at the Forschungszentrum Jülich as part of JOYCE. The radar transmits a linearly polarized signal at 35.5 GHz (Ka-Band) 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 has full 3D-scanning possibilities for the entire upper hemisphere.

Measurement modes

  • Vertically pointing observations with integration times up to 1 seconds.
  • Full azimuth/elevation scanning capability for horizontal variability of clouds as well as 3D wind vectors in clouds

JOYCE-CF Standard Operation Procedures

  • Standard measurement mode is vertically pointing, 2 second integration time
  • Every 30 minutes one azimuth scan at 83° elevation angle with 6° azimuth resolution (duration ~2 minutes) for horizontal wind within clouds and the boundary layer (if sufficient insects are present)

Calibrations and data quality assurance procedures

  • Check with co-located disdrometer to find out reflectivity offsets
  • Consistency check with other cloud radars

Data availability

Some of the following data products are provided via Cloudnet ACTRIS cloudnet website with a temporal resolution of 30 seconds. If you would like to have additional data with better resolution or raw Doppler spectra please fill the data request sheet and send it to

Dataset Temporal resolution File size Filename Remarks
Radar reflectivity factor 30 seconds 1 file per day (30-50 MB) available via Cloudnet
Doppler velocity 30 seconds 1 file per day (30-50 MB) available via Cloudnet
Spectral width 30 seconds 1 file per day (30-50 MB) available via Cloudnet
Linear depolarization ratio 30 seconds 1 file per day (30-50 MB) available via Cloudnet
Profiles of horizontal wind 30 minutes 1 file per day (30-50 MB)
Radar moments 2 seconds variable size (up to 30 MB/hour in case of thick clouds) YYYYMMDD_HHMM.mmclx.gz zipped NetCDF file
Doppler spectra, Radar moments 2 seconds variable size (up to 2 GB/hour in case of thick clouds) YYYYMMDD_HHMM.znc NetCDF file
Doppler spectra 2 seconds variable size (up to 1 GB/hour in case of thick clouds) YYYYMMDD_HHMM.zspc Binary file

Composite products using data from JOYRAD-35

  • Dual-wavelength ratio Ka/X-Band and Ka/W-Band Link to Quicklooks
  • Cloudnet target classification uses Radar moments data from JOYRAD-35. Combined with microwave radiometer and ceilometer observation, clouds are characterized by their geometrical extent as well as their microphysical properties. Link to Cloudnet

Data quicklooks can be found in the JOYCE quicklook archive and in the METEK archive

Measurement examples

JOYRAD-35_obs JOYRAD-35_wind
Example time series of JOYRAD-35 observations (radar moments / horizontal wind)

Example time series of Cloudnet target classification

JOYRAD-35 History

Period Place Project
2017 Instrument upgrade
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

JOYRAD-35 ©B. Pospichal
Cloud radar JOYRAD-35 installed at Jülich

Technical 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
joyrad35.txt · Last modified: 2021/02/03 10:02 by bpospich