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--- mfrsr [2020/08/30 17:46] – [Multi-Filter Rotating Shadowband Radiometer (MFRSR)] bpospich
+++ mfrsr [2021/03/01 10:16] (current) – [Link to current observations] bpospich
@@ Line 6: / Line 6: @@
 ===== Principle =====
-The **Micro Rain Radar (MRR)** is a vertical pointing FM-CW (frequency modulated –continuous wave) Doppler radar operating at 24.1 GHz (K-band, 12.4 mm wavelength). The emitted radar signal (only 50 mW transmitting power) is backscattered by falling hydrometeors (rain, graupel, snow). From the Doppler spectra the radar reflectivity factor (Ze) and the terminal fall velocity distribution can be derived.
+The **Multifilter Rotating Shadowband Radiometer (MFRSR)** is a passive instrument that measures global and diffuse components of solar irradiance at one broadband channel and at six narrowband channels, i. e. at 415, 500, 615, 673, 870, and 940 nm. Direct irradiance is subsequently calculated from the diffuse and global measured components. Each MFRSR measurement sequence includes measurements at four different shadowband positions: 1) at nadir (home position), 2) at the first side-band position, 3) sun-blocked, 4) at the second side-band position. The side-band measurements are used to correct for the portion of the sky obscured by the shadowband. From the MFRSR measurements, the aerosol optical depth at the wavelengths 415, 500, 615, 673 and 870 nm as well as the Angstrom exponent can be derived. For single-layer “horizontally homogeneous” liquid clouds, layer cloud optical depth and effective radius can also be retrieved.
-In case of rain the Doppler spectra can be used to derive vertical profiles of microphysical rain properties like drop size distribution and rain rate.
-The MRR system was also studied for its potential to observe snowfall ([[https://link.springer.com/article/10.1007/s00703-011-0142-z|Kneifel et al., 2011]]). Also, an improved MRR algorithm **IMProToo** most suitable for snowfall observations has been developed at IGMK ([[https://amt.copernicus.org/articles/5/2661/2012/amt-5-2661-2012.html|Maahn and Kollias, 2012]]). It is freely available on [[https://github.com/maahn/IMProToo|Github]].
-===== 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
+  * Direct, diffuse, and total irradiance in 5 spectral bands
-  * Vertical resolution 35 meters (max. range = 1085 m)
+  * Temporal resolution 15 seconds
+ ===== Calibration and data quality control =====
+  * Absolute calibration
-===== 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 =====
@@ Line 31: / Line 27: @@
 ^ 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)   |
+| Radiances   | 15 seconds    | 1 file per day (~1.5 MB)     | //DayYYYYMMDD.txt//  |    |
-| IMProToo (NetCDF)   | 1 minute    | 1 file per day (20-30 MB)     | //YYYYMMDD_jue_mrr_improtoo_0-101.nc.gz//  | [[https://github.com/maahn/IMProToo|IMProToo]] product (zipped) |
-Both available datasets include Doppler spectra, drop spectra, radar reflectivity, rain rate, and fall velocity.
@@ Line 40: / Line 33: @@
 ===== Link to current observations =====
-Data quicklooks can be found in the [[http://gop.meteo.uni-koeln.de/~Hatpro/dataBrowser/dataBrowser3.html?site=JOYCE&date=-1&UpperLeft=MRR_IMProToo&UpperRight=MRR_AveData&LowerRight=Parsivel-Pluvio-MRR_precipitation-rate|JOYCE quicklook browser]].
+Data quicklooks can be found in the [[http://atmos.meteo.uni-koeln.de/~hatpro/dataBrowser/dataBrowser2.html?site=JOYCE&date=-1&UpperLeft=MFRSR_Narrowband&UpperRight=MFRSR_Broadband|JOYCE quicklook browser]].
 ===== Measurement examples =====
-{{wiki:examples:20200617_jue_mrr_improtoo.png?direct&400|MRR_IMProToo}}
+{{wiki:examples:20200806_mfrsr_jue_l1_narrowband.png?direct&350|)}} \\
-{{wiki:examples:rr_pars_plu_mrr_20200617.png?direct&400|Rain_rate}} \\
+//Example time series of MFRSR spectral irradiances (total, diffuse, and direct) on 6 August 2020 at JOYCE.//
-//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 =====
+===== MFRSR History =====
 ^  Period  ^  Place  ^  Project  ^
-| 03/2012 - today | Research Centre Jülich | [[http://www.tr32.de|TR32]] |
+| 06/07/2015 - today | [[http://www.fz-juelich.de/|Research Center Jülich]], Germany | JOYCE |
-| 04/2008 - 10/2011 | [[http://www.fz-juelich.de/icg/icg-4/index.php?index=500|Selhausen]], Germany | [[http://www.tr32.de|TR32]] |
-| 05 - 12/2007 | Heselbach, Blackforest, Germany | COPS |
-| 2006 - 2007 | Nangatchori, Benin | [[http://amma-international.org/|AMMA]] |
@@ Line 63: / Line 53: @@
 ===== Technical Specifications =====
-^  Parameter  ^  Specification  ^
+^ Parameter  ^ Specification ^
-| Frequency | 24.1 GHz |
+| Wavelengths | Silicon broadband pyranometer, 415, 500, 615, 673, 870, 940 nm |
-| Wavel | 12.4 mm |
+| FWHM bandwidth | 10 nm |
-| Radar Type | FM-CW |
+| Cosine response | Better than 5% for 0 - 80° zenith angle; better than 1% with corrections  |
-| Transmit Power | 50 mW |
+| Temporal Resolution | 15 s |
-| Receiver | Single Polarization |
+| Weight | 4.55 kg |
-| Power consumption (radar) | 25 W |
+| Power Consumption | 110/220 VAC, 50/60 Hz (50 watts maximum) |
-| Total power cons. incl heating | 525 W |
+| Manufacturer | [[http://www.yesinc.com/|YES Inc.]]  |
-| Max. range | 6 km |
-| Range Resolution | 10-200 m |
-| No. of range gates | 30 |
-| Temporal resolution | 10 s |
-| Antenna diameter | 0.5 m |
-| Beam width (2-way, 6 dB) | 1.5° |
-| Manufacturer | [[http://www.metek.de/|Metek]] |