Transmission Reach Attainable for Single-Polarization and PolMux Coherent Star 16QAM Systems in Comparison to 8PSK and QPSK at 10Gbaud

Recent and archived data from weather radar networks are extensively used for the quantification of continent-wide bird migration patterns. While the process of discriminating birds from weather signals is well established, insect contamination is still a problem. We present a simple method combining two Doppler radar products within a Gaussian mixture model to estimate the proportions of birds and insects within a single measurement volume, as well as the density and speed of birds and insects. This method can be applied to any existing archives of vertical bird profiles, such as the European Network for the Radar surveillance of Animal Movement repository, with no need to recalculate the huge amount of original polar volume data, which often are not available.

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Comparison of Radar-Based Hail Detection Using Single- and Dual-Polarization

Remote Sensing ◽

10.3390/rs11121436 ◽

2019 ◽

Vol 11 (12) ◽

pp. 1436 ◽

Cited By ~ 1

Author(s):

Skripniková ◽

Řezáčová

Keyword(s):

Comparative Analysis ◽

Heavy Rain ◽

Radar Data ◽

Severe Weather ◽

Detection Methods ◽

Polarimetric Radar ◽

Dual Polarization ◽

Rain Events ◽

Single Polarization ◽

Strong Agreement

The comparative analysis of radar-based hail detection methods presented here, uses C-band polarimetric radar data from Czech territory for 5 stormy days in May and June 2016. The 27 hail events were selected from hail reports of the European Severe Weather Database (ESWD) along with 21 heavy rain events. The hail detection results compared in this study were obtained using a criterion, which is based on single-polarization radar data and a technique, which uses dual-polarization radar data. Both techniques successfully detected large hail events in a similar way and showed a strong agreement. The hail detection, as applied to heavy rain events, indicated a weak enhancement of the number of false detected hail pixels via the dual-polarization hydrometeor classification. We also examined the performance of hail size detection from radar data using both single- and dual-polarization methods. Both the methods recognized events with large hail but could not select the reported events with maximum hail size (diameter above 4 cm).

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A New 21-cm Line Survey of the LMC

Symposium - International Astronomical Union ◽

10.1017/s0074180900040560 ◽

1984 ◽

Vol 108 ◽

pp. 395-396

Author(s):

K. Rohlfs ◽

J. Kreitschmann ◽

J. V. Feitzinger

Keyword(s):

Noise Temperature ◽

Beam Width ◽

Main Beam ◽

Corrugated Waveguide ◽

Line Survey ◽

Single Polarization ◽

Switching Mode ◽

Half Power ◽

Channel Separation ◽

Made In

The measurements were made in Feb. 1982 with the Parkes 64 m telescope using a corrugated waveguide horn with total half-power beam width of 15′, the first sidelobes being 19 dB down, resulting in an aperture efficiency ηA=0.53±0.007, a main beam efficiency of ηmb=0.80±0.005 and a ratio of source flux to antenna temperature of Γ=0.62±0.1 K/Jy (Murray, priv. comm.). A cooled two channel FET frontend used in the frequency switching mode with Δν = 2 MHz resulted in a system noise temperature at zenith of Tsyst = 40 K for one channel and Tsyst = 50 K for the other. Each frontend channel received a single polarization mode, and this radiation was then further analysed in a 2 × 512 channel autocorrelation spectrometer set at a channel separation of 3.906 KHz corresponding to a velocity resolution of V = 0.824 km s−1. Hanning smoothed this resulted in a σT = 0.05 K for the average of both polarization.

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