====== NYRAD35 35 GHz cloud radar ======
//Mentor: [[https://geomet.uni-koeln.de/institut/beschaeftigte/mech|M. Mech]], Data: [[https://geomet.uni-koeln.de/institut/beschaeftigte/ebell|K. Ebell]] //

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NYRAD35 ([[http://www.radiometer-physics.de/|RPG]]) on the roof of the AWIPEV atmospheric observatory.


===== Principle =====
The NYRAD35 is a dual-polarization simultaneous transmission and simultaneous reception (STSR; also referred to as hybrid-mode, or STAR, simultaneous transmission and reception) radar, with elevation-scanning capabilities. The scanner can perform full 180° scans in elevation and is operated at a constant azimuth of approximately 27°, i.e., along the north-north-east to south-south-west direction. STSR radars receive at both horizontal and vertical polarization but transmit a linearly polarized signal at 45° (between the vertical and horizontal polarization planes). This allows both for linear depolarization ratio (LDR) observations in zenith and typical dual-polarization variable observations at low elevations, such as differential reflectivity (ZDR) or specific differential phase (KDP). Matching Ka- and W-band observations at zenith allows calculation of the DWR, providing information on the characteristic size of the ice particle population.


===== Data =====

  * If you are interested in receiving data please contact: // [[http://www.geomet.uni-koeln.de/das-institut/mitarbeiter/ebell/|Kerstin Ebell]] //

  * [[https://atmos.meteo.uni-koeln.de/~hatpro/dataBrowser/dataBrowser2.html?site=Ny-Alesund&date=0&UpperLeft=NyRAD35-Overview&UpperRight=NyRAD35-Polarimetry | Quicklook archive]]

===== Deployment =====
^  Period  ^  Place  ^  Project  ^
|  23/01/2025 - today       | [[http://www.awipev.eu/|AWIPEV at Ny-Ålesund]], Norway | [[http://www.ac3-tr.de/|(AC)3]] |
|  01/10/2021 - 06/03/2024  | [[http://www.awipev.eu/|AWIPEV at Ny-Ålesund]], Norway | [[http://www.ac3-tr.de/|(AC)3]] |

===== Specifications =====
^ Parameter  ^ Specification  ^ Remark  ^
| Frequency | 35 GHz | corresponds to wavelength of 8.6 mm; bandwidth up to ± 100 MHz |
|IF Range | 0.3 to 3.7 MHz |  |
| Transmitter Power | 15 W | solid state amplifier  |
| Antenna gain | 48.0 dB |  |
| Beam Width | 0.8° FWHM |  |
| Polarisation | Dual-polarization (STSR) | receives V/H polarised radiation and emits at 45° (between vertical and horizontal directions) linearly polarized radiation (="simultaneous transmission simultaneous reception" (STSR)) |
| Dynamic Range | -43 dBZe to +30 dBZ | valid for 5 km distance, 30 m resolution, and 10 s sampling time  |
| Ranging | 50 m to 12 km | maximum 18 km |
| Calibration | Transmitter power monitoring, Receiver Dicke switch (for radar and passive channel), Hot/Cold absolute receiver calibration | Accuracy ±1 dB |
| A/D Sampling Rate | 11.45 MHz |  |
| Profile Sampling Rate | ≥1 s | adjustable |
| Vertical Resolution | 4 m to 30 m | 4 m in a limited distance range |
| Doppler Resolution | ± 4 cm/s | or better |
| Doppler Range | ± 10 m/s max. |  |
| Chirp Variations | 3 typical | 5 possible, re-programmable |
| Passive Channels | 31.4 GHz | for integral liquid water (LWP) detection (200 MHz BW) |
| Passive Channel Noise Figure | 3.7 dB |  |
| Data Products | Raw spectra, Spectral polarimetric parameters, Reflectivity, Mean Doppler velocity, Doppler width, Skewness, Kurtosis, Differential reflectivity, Differential phase shift, Correlation coefficient |  |
| Data Formats | proprietary binary, netCDF (conformity with CF convention) |  |
| Rain/Snow/Dew Mitigation System | Strong dew blower (4000 m3/h ), radomes with hydrophobic coating | |
| Weight | Radar main body: 160 kg, Table: 35 kg, Blower: 109 kg |  |
| Maximum Power Consumption | Radar: max. 1100 W, Blower: 850 W, Scanner: 800 W, 230 V AC, 50-60 Hz |  |
| Elevation Scanning | zenith mode, 30° low-elevation mode | azimuth direction fixed to 27° (along north-north-east to south-south-west direction); elevation angle adjustable; alternating continuous zenith/low-elevation measurements with 1°/sec elevation scan  in-between |
| Manufacturer | [[http://www.radiometer-physics.de/|RPG]] | 

===== References =====
Chellini, G., R. Gierens, K. Ebell, T. Kiszler, P. Krobot, A. Myagkov, V. Schemann, and S. Kneifel, 2023: Low-level mixed-phase clouds at the high Arctic site of Ny-Ålesund: A comprehensive long-term dataset of remote sensing observations, Earth Syst. Sci. Data, 15, 5427–5448, https://doi.org/10.5194/essd-15-5427-2023

Chellini, G., R. Gierens, and S. Kneifel, 2022: Ice aggregation in low-level mixed-phase clouds at a high Arctic site: Enhanced by dendritic growth and absent close to the melting level. Journal of Geophysical Research: Atmospheres, 127, e2022JD036860. https://doi.org/10.1029/2022JD036860