scholarly journals End to end simulator for the WIVERN W-band Doppler conically scanning spaceborne radar

2021 ◽  
Author(s):  
Alessandro Battaglia ◽  
Paolo Martire ◽  
Eric Caubet ◽  
Laurent Phalippou ◽  
Fabrizio Stesina ◽  
...  
Keyword(s):  
Doppler Radar ◽  
Cloud Model ◽  
W Band ◽  
Trade Offs ◽  
Phase 0 ◽  
Wind Lidar ◽  
End To End ◽  
Scanning Geometry ◽  
First Time ◽  
Spaceborne Radar

Abstract. The WIVERN (WInd VElocity Radar Nephoscope) mission, soon entering in Phase-0 of the ESA Earth Explorer program, promises to complement Doppler wind lidar by globally observing, for the first time, vertical profiles of winds in cloudy areas. This work describes an end to end simulator of the WIVERN conically scanning 94 GHz Doppler radar, the only payload of the mission. Specific features of the simulator are: the conically scanning geometry; the inclusion of cross-polarization effects and of the simulation of a radiometric mode; the applicability to global cloud model outputs via an orbital model; the incorporation of a mispointing model accounting for thermo-elastic distortions, microvibrations, star-trackers uncertainties, etc.; the inclusion of the surface clutter. Some of the simulator capabilities are showcased for a case study involving a full rotational scan of the instrument. The simulator represents a very useful tool for studying the performances of the WIVERN concept and possible trade-offs for the different configurations (e.g. different antenna sizes, pulse lengths, antenna patterns, .....). Thanks to its modular structure the simulator can be easily adapted to different orbits, different scanning geometries and different frequencies.

scholarly journals A unique mating pattern of Panorpodes kuandianensis (Mecoptera: Panorpodidae)

2017 ◽  
Vol 86 (3) ◽  
pp. 229-237 ◽  
Author(s):  
Xin Tong ◽  
Lu Jiang ◽  
Bao-Zhen Hua
Keyword(s):  
Mating Behavior ◽  
Sexual Conflict ◽  
Sperm Transfer ◽  
Nuptial Gift ◽  
Mating Pattern ◽  
End To End ◽  
Mating Behaviors ◽  
First Time

Sexually reproductive insects exhibit diverse mating behaviors. However, the mating pattern remains unknown for Panorpodes of Panorpodidae to date. In this study, we investigated the mating behavior and copulatory mechanism of the short-faced scorpionfly Panorpodes kuandianensis Zhong, Zhang and Hua, 2011 for the first time. The results show that the male provides a salivary mass as a nuptial gift to the female and starts to copulate with the female in a V-shaped position, then changes to an end-to-end position by temporarily twisting the female abdominal segments VII−IX by 180°. During mating the basal processes and the basal teeth of the gonostyli and the hypandrium are used to obtain copulation and sustain the coupling of genitalia to secure successful sperm transfer. This unique mating pattern is greatly different from that of other Mecoptera reported and is likely evolved as an adaptation in the context of sexual conflict.

scholarly journals Non-Contact Measurement of Human Respiration and Heartbeat Using W-band Doppler Radar Sensor

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5209 ◽  
Author(s):  
Heesoo Kim ◽  
Jinho Jeong
Keyword(s):  
Doppler Radar ◽  
Band Pass Filter ◽  
Radar Sensor ◽  
Pass Filter ◽  
Contact Measurement ◽  
W Band ◽  
Compact Size ◽  
Human Respiration ◽  
Low Pass ◽  
Respiration Signal

This paper presents a W-band continuous-wave (CW) Doppler radar sensor for non-contact measurement of human respiration and heartbeat. The very short wavelength of the W-band signal allows a high-precision detection of the displacement of the chest surface by the heartbeat as well as respiration. The CW signal at 94 GHz is transmitted through a high-gain horn antenna to the human chest at a distance of 1 m. The phase-modulated reflection signal is down-converted to the baseband by the quadrature mixer with an excellent amplitude and phase matches between I and Q channels, which makes the IQ mismatch correction in the digital domain unnecessary. The baseband I and Q data are digitized using data acquisition (DAQ) board. The arctangent demodulation with automatic phase unwrapping is applied to the low-pass filtered I and Q data to effectively solve the null point problem. A slow-varying DC component is rejected in the demodulated signal by the trend removal algorithm. Then, the respiration signal with a frequency of 0.27 Hz and a displacement of ~6.1 mm is retrieved by applying a low-pass filter. Finally, the respiration signal is removed by the band-pass filter and the heartbeat signal is extracted, showing a frequency of 1.35 Hz and a displacement of ~0.26 mm. The extracted respiration and heartbeat rates are very close to the manual measurement results. The demonstrated W-band CW radar sensors can be easily applied to find the angular location of the human body by using a phased array under a compact size.

A W-band comet-jet Doppler radar prototype

2018 ◽  
Author(s):  
Ken B. Cooper ◽  
Raquel Rodriguez Monje ◽  
Maria Alonso-delPino ◽  
Robert J. Dengler ◽  
Corey J. Cochrane ◽  
...  
Keyword(s):  
Doppler Radar ◽  
W Band

X- and W-band mobile Doppler radar observations from VORTEX2 and current developments

2011 ◽  
Author(s):  
S. J. Frasier ◽  
V. Venkatesh ◽  
K. Orzel ◽  
T. Hartley ◽  
J. Salazar ◽  
...  
Keyword(s):  
Doppler Radar ◽  
Radar Observations ◽  
W Band

scholarly journals Understanding Heavy Lake-Effect Snowfall: The Vertical Structure of Radar Reflectivity in a Deep Snowband over and downwind of Lake Ontario

2016 ◽  
Vol 144 (11) ◽  
pp. 4221-4244 ◽  
Author(s):  
Dan Welsh ◽  
Bart Geerts ◽  
Xiaoqin Jing ◽  
Philip T. Bergmaier ◽  
Justin R. Minder ◽  
...  
Keyword(s):  
Vertical Velocity ◽  
Doppler Radar ◽  
Lake Ontario ◽  
Radar Reflectivity ◽  
Distribution Data ◽  
W Band ◽  
Lake Effect ◽  
X Band ◽  
Axis Parallel ◽  
Frictional Convergence

Abstract The distribution of radar-estimated precipitation from lake-effect snowbands over and downwind of Lake Ontario shows more snowfall in downwind areas than over the lake itself. Here, two nonexclusive processes contributing to this are examined: the collapse of convection that lofts hydrometeors over the lake and allows them to settle downwind; and stratiform ascent over land, due to the development of a stable boundary layer, frictional convergence, and terrain, leading to widespread precipitation there. The main data sources for this study are vertical profiles of radar reflectivity and hydrometeor vertical velocity in a well-defined, deep long-lake-axis-parallel band, observed on 11 December 2013 during the Ontario Winter Lake-effect Systems (OWLeS) project. The profiles are derived from an airborne W-band Doppler radar, as well as an array of four K-band radars, an X-band profiling radar, a scanning X-band radar, and a scanning S-band radar. The presence of convection offshore is evident from deep, strong (up to 10 m s−1) updrafts producing bounded weak-echo regions and locally heavily rimed snow particles. The decrease of the standard deviation, skewness, and peak values of Doppler vertical velocity during the downwind shore crossing is consistent with the convection collapse hypothesis. Consistent with the stratiform ascent hypothesis are (i) an increase in mean vertical velocity over land; and (ii) an increasing abundance of large snowflakes at low levels and over land, due to depositional growth and aggregation, evident from flight-level and surface particle size distribution data, and from differences in reflectivity values from S-, X-, K-, and W-band radars at nearly the same time and location.

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