Table of Contents

NYRAD35 35 GHz cloud radar

Mentor: M. Mech, Data: K. Ebell

NYRAD35 (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

Deployment

Period Place Project
23/01/2025 - today AWIPEV at Ny-Ålesund, Norway (AC)3
01/10/2021 - 06/03/2024 AWIPEV at Ny-Ålesund, Norway (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 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