====== Disdrometer ======

{{:wiki:instruments:parsivel07.jpg?direct&600|Parsivel ©B. Pospichal}} \\
//Parsivel disdrometer installed at Jülich//

===== Principle =====
The **OTT Parsivel<sup>2</sup>** 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





===== JOYCE-CF Standard Operation Procedures =====

  * Temporal resolution 1 minute
  * Precipitation amount 
  * Particle concentration and fall velocity per velocity class and diameter class)
  * Equivalent radar reflectivity factor from particle size distribution (6th moment)
  * Fall velocity in 32 classes (0.05, 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0.85, 0.95, 1.1, 1.3, 1.5, 1.7, 1.9, 2.2, 2.6, 3, 3.4, 3.8, 4.4, 5.2, 6, 6.8, 7.6, 8.8, 10.4, 12, 13.6, 15.2, 17.6, 20.8 ms<sup>-1</sup>)
  * Particle diameter in 32 classes (0.062, 0.187, 0.312, 0.437, 0.562, 0.687, 0.812, 0.937, 1.062, 1.187, 1.375, 1.625, 1.875, 2.125, 2.375, 2.75, 3.25, 3.75, 4.25, 4.75, 5.5, 6.5, 7.5, 8.5, 9.5, 11, 13, 15, 17, 19, 21.5, 24.5 mm)



===== Data availability =====

Data are available on request, please fill the {{ :joyce_data_request_form.pdf |data request sheet}} and send it to [[mailto:info@joyce.cloud|info@joyce.cloud]].


^ Dataset     ^ Temporal resolution       ^ File size          ^ Filename   ^ Remarks   ^ 
| All variables (see above)   | 1 minute    | 1 file per day (6-7 MB)     | //sups_joy_dm00_l1_any_v00_YYYYMMDD.nc//  | in future available via SAMD |




===== Link to current observations =====

Data quicklooks can be found in the [[http://atmos.meteo.uni-koeln.de/~hatpro/dataBrowser/dataBrowser3.html?site=JOYCE&date=-1&UpperLeft=Parsivel_Overview&UpperRight=Parsivel-Pluvio-MRR_precipitation-rate&LowerRight=Parsivel-Pluvio-MRR_Accumulated_Precipitation|JOYCE quicklook browser]].

===== Measurement examples =====

{{wiki:examples:parsivel_overview_20200617.png?direct&400|Parsivel Overview}}
{{wiki:examples:rr_pars_plu_mrr_20200617.png?direct&400|Rain_rate}} \\
//Example time series of Parsivel disdrometer (left: Parsivel drop diameter, fall speed, particle type, precipitation rate / right: rain rates from Parsivel (top), compared to [[pluvio|Pluviometer]] and [[mrr|MRR]])//




===== Disdrometer History ====
^  Period  ^  Place  ^  Project  ^
| 08/2013 - today | [[http://www.fz-juelich.de/|Research Center Jülich]], Germany | [[http://www.tr32.de|TR32]] |



===== 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 | [[https://www.ott.com/products/meteorological-sensors-26/ott-parsivel2-laser-weather-sensor-2392/|OTT]]  |