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Table of Contents
Disdrometer
Parsivel disdrometer installed at Jülich
Principle
The OTT Parsivel2 is a laser-based optical system for complete and reliable measurement of all types of precipitation. The size range of measurable liquid precipitation particles is from 0.2 … 5 mm, for solid precipitation particles it is from 0.2 … 25 mm. In the process, precipitation particles can have a velocity of from 0.2 … 20 m/s. The precipitation particles are categorized as follows:
- Drizzle
- Drizzle with rain
- Rain
- Rain, drizzle with snow
- Snow
- Snow grains
- Freezing rain
- Hail
Measurement modes
- Vertically pointing observations with integration times from 10 to 3600 seconds.
- The range resolution can be varied from 10 to 200 m which determines together with the 30 range gates the system's maximum height range of 300 to 6000 m.
JOYCE-CF Standard Operation Procedures
- Temporal resolution 10 seconds
- Vertical resolution 35 meters (max. range = 1085 m)
Calibrations and data quality assurance procedures
- ImProToo features a noise removal based on recognition of the most significant peak and a dynamic dealiasing routine which allows observations even if the Nyquist velocity range is exceeded.
Data availability
Data are available on request, please fill the data request sheet and send it to info@joyce.cloud.
| Dataset | Temporal resolution | File size | Filename | Remarks |
|---|---|---|---|---|
| Raw data (ASCII) | 10 seconds | 1 file per day (~15 MB) | YYYYMMDD_jue_mrr_raw_txt.gz | METEK format (zipped) |
| IMProToo (NetCDF) | 1 minute | 1 file per day (20-30 MB) | YYYYMMDD_jue_mrr_improtoo_0-101.nc.gz | IMProToo product (zipped) |
Both available datasets include Doppler spectra, drop spectra, radar reflectivity, rain rate, and fall velocity.
Link to current observations
Data quicklooks can be found in the JOYCE quicklook browser.
Measurement examples
Example time series of MRR observations (left: IMProToo radar reflectivity, spectral width, rain rate and mean spectral noise / right: rain rates from MRR (bottom), compared to Parsivel and Pluvio)
MRR History
Technical Specifications
| Parameter | Specification |
|---|---|
| Wavelength | 780 nm |
| Output power | 0,5mW |
| Beam dimension | W x D 180 x 30 mm |
| Measurement area | 54 cm², detection of border events |
| Particle size of liquid precipitation | 0.2 … 5 mm |
| Particle size of solid precipitation | 0.2 … 25 mm |
| Particle velocity | 0.2 … 20 m/s |
| Rain rate Minimal intensity | 0.001 mm/h drizzle/rain |
| Rain rate Maximal intensity | 1,200 mm/h |
| Prod. Temporal Resolution | 60 s |
| Accuracy | ±5 % (liquid) / ±20 % (solid) |
| Dimensions (HxWxD) | 670 x 600 x 114 mm |
| Power supply | 10 … 28V DC, reverse polarity protection |
| Current drawn | Electronics 65 mA at 24 V DC / Heating 2/4 A; 12/24 V DC |
| Manufacturer | OTT |