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Table of Contents
Broadband radiation
Sun tracker and Radiation sensors installed at Jülich
Principle
Two pyranometers (CMP 21), a pyrheliometer (CHP 1) and a pyrgeometer (CGR 4) are used to measure solar shortwave radiation and terrestrial longwave radiation. One pyranometer receives total downward solar irradiance. The other instruments are mounted on a suntracker (SOLYS 2) measuring diffuse downward solar irradiance (shaded pyranometer), direct solar irradiance (pyrheliometer) and terrestrial downward irradiance (shaded pyrgeometer). All instruments were produced and calibrated by Kipp&Zonen B.V., Netherlands.
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 info@joyce.cloud
| Dataset | Temporal resolution | File size | Filename | Remarks |
|---|---|---|---|---|
| Radar reflectivity factor | 30 seconds | 1 file per day (30-50 MB) | YYYYMMDD_juelich_categorize.nc | available via Cloudnet |
| Doppler velocity | 30 seconds | 1 file per day (30-50 MB) | YYYYMMDD_juelich_categorize.nc | available via Cloudnet |
| Spectral width | 30 seconds | 1 file per day (30-50 MB) | YYYYMMDD_juelich_categorize.nc | available via Cloudnet |
| Linear depolarization ratio | 30 seconds | 1 file per day (30-50 MB) | YYYYMMDD_juelich_categorize.nc | available via Cloudnet |
| Profiles of horizontal wind | 30 minutes | 1 file per day (30-50 MB) | YYYYMMDD_joyrad35_wind_profile.nc | |
| 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
Link to current observations
Data quicklooks can be found in the JOYCE quicklook archive and in the METEK archive
Measurement examples
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 |
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 |