RETRIEVAL OF MESOSPHERIC NEUTRAL WIND BASED ON AGILEDARN HF RADAR

2022 ◽  
Vol 107 ◽  
pp. 25-34
Author(s):  
Guangming Li
Keyword(s):  
Hf Radar ◽  
Neutral Wind

scholarly journals Mid-latitude <i>E</i>-region bulk motions inferred from digital ionosonde and HF radar measurements

2004 ◽  
Vol 22 (11) ◽  
pp. 3789-3798 ◽  
Author(s):  
G. C. Hussey ◽  
C. Haldoupis ◽  
A. Bourdillon ◽  
J. Delloue ◽  
J. T. Wiensz
Keyword(s):  
Hf Radar ◽  
Neutral Wind ◽  
Angle Of Arrival ◽  
Neutral Winds ◽  
Sporadic E Layers ◽  
E Region ◽  
Radar Measurements ◽  
Sporadic E ◽  
Coherent Radar ◽  
Coherent Backscatter

Abstract. In the mid-latitude E-region there is now evidence suggesting that neutral winds play a significant role in driving the local plasma instabilities and electrodynamics inside sporadicE layers. Neutral winds can be inferred from coherent radar backscatter measurements of the range-/azimuth-time-intensity (RTI/ATI) striations of quasi-periodic (QP) echoes, or from radar interferometer/imaging observations. In addition, neutral winds in the E-region can be estimated from angle-of-arrival ionosonde measurements of sporadic-E layers. In the present paper we analyse concurrent ionosonde and HF coherent backscatter observations obtained when a Canadian Advanced Digital Ionosonde (CADI) was operated under a portion of the field-of-view of the Valensole high frequency (HF) radar. The Valensole radar, a mid-latitude radar located in the south of France with a large azimuthal scanning capability of 82° (24° E to 58° W), was used to deduce zonal bulk motions of QP echoing regions using ATI analysis. The CADI was used to measure angle-of-arrival information in two orthogonal horizontal directions and thus derive the motion of sporadic-E patches drifting with the neutral wind. This paper compares the neutral wind drifts of the unstable sporadic-E patches as determined by the two instruments. The CADI measurements show a predominantly westward aligned motion, but the measured zonal drifts are underestimated relative to those observed with the Valensole radar.

scholarly journals An Improved Meteor Echo Recognition Algorithm for SuperDARN HF Radar

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1971
Author(s):  
Guangming Li ◽  
Jingye Yan ◽  
Ailan Lan
Keyword(s):  
Power Distribution ◽  
Power Doppler ◽  
Spectral Width ◽  
Hf Radar ◽  
Integration Time ◽  
Doppler Velocity ◽  
Neutral Wind ◽  
Extraction Algorithm ◽  
Radar Meteor ◽  
Improved Algorithm

The SuperDARN HF radars can be used for meteor observation and inversion of mid-upper atmosphere neutral wind using observed meteor echo Doppler velocities. Aiming at the problem that the extraction of meteor echo based on echo power, Doppler velocity and spectral width is rough and contains ionospheric echo, this paper optimizes the extraction algorithm of meteor echo. Based on the AgileDARN HF radar’s digital characteristics, the observation method of meteor echo was improved, and we designed a meteor observation mode without changing the hardware system: using a meteor observation with a 7.5 km range resolution and a 2 s integration time, we extracted the Doppler characteristics of different echo types at meteor echo ranges; according to these features, the extraction algorithm of meteor echo was optimized. By analyzing the measured data, the characteristics of diurnal variation, power distribution, Doppler velocity distribution and spectral width distribution of meteor echo extracted by the optimization algorithm were obtained. The meteor echo characteristics obtained by the improved algorithm are more consistent with the theoretical analysis; thus, the improved algorithm is better than the SuperDARN high frequency radar meteor echo extraction algorithm and has good performance. The meteor echo extraction algorithm presented in this paper can extract the meteor echo more accurately, so that the atmospheric neutral wind can be retrieved more accurately. At the same time, the proposed algorithm is not only applicable to AgileDARN HF radar meteor observation mode data, but also to AgileDARN and SuperDARN normal mode data, which is beneficial to expand the data application of SuperDARN radars.

scholarly journals Gap Filling of the CALYPSO HF Radar Sea Surface Current Data through Past Measurements and Satellite Wind Observations

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Adam Gauci ◽  
Aldo Drago ◽  
John Abela
Keyword(s):  
Oil Spills ◽  
Surface Current ◽  
Radar Data ◽  
Current Data ◽  
Hf Radar ◽  
Sea Surface ◽  
Machine Learning Techniques ◽  
Learning Techniques ◽  
Spatial Coverage ◽  
Essential Components

High frequency (HF) radar installations are becoming essential components of operational real-time marine monitoring systems. The underlying technology is being further enhanced to fully exploit the potential of mapping sea surface currents and wave fields over wide areas with high spatial and temporal resolution, even in adverse meteo-marine conditions. Data applications are opening to many different sectors, reaching out beyond research and monitoring, targeting downstream services in support to key national and regional stakeholders. In the CALYPSO project, the HF radar system composed of CODAR SeaSonde stations installed in the Malta Channel is specifically serving to assist in the response against marine oil spills and to support search and rescue at sea. One key drawback concerns the sporadic inconsistency in the spatial coverage of radar data which is dictated by the sea state as well as by interference from unknown sources that may be competing with transmissions in the same frequency band. This work investigates the use of Machine Learning techniques to fill in missing data in a high resolution grid. Past radar data and wind vectors obtained from satellites are used to predict missing information and provide a more consistent dataset.

Spatio-Temporal Deep Learning for Ocean Current Prediction Based on HF Radar Data

2019 ◽  
Author(s):  
Nathachai Thongniran ◽  
Peerapon Vateekul ◽  
Kulsawasd Jitkajornwanich ◽  
Siam Lawawirojwong ◽  
Panu Srestasathiern
Keyword(s):  
Deep Learning ◽  
Radar Data ◽  
Hf Radar ◽  
Ocean Current ◽  
Spatio Temporal

scholarly journals High resolution observations of spectral width features associatedwith ULF wave signatures in artificial HF radar backscatter

2004 ◽  
Vol 22 (1) ◽  
pp. 169-182 ◽  
Author(s):  
D. M. Wright ◽  
T. K. Yeoman ◽  
L. J. Baddeley ◽  
J. A. Davies ◽  
R. S. Dhillon ◽  
...  
Keyword(s):  
High Resolution ◽  
Plasma Source ◽  
Spectral Width ◽  
Hf Radar ◽  
Mhd Waves ◽  
Small Scale ◽  
Ulf Waves ◽  
Source Population ◽  
Radar Backscatter ◽  
Field Lines

Abstract. The EISCAT high power heating facility at Tromsø, northern Norway, has been utilised to generate artificial radar backscatter in the fields of view of the CUTLASS HF radars. It has been demonstrated that this technique offers a means of making very accurate and high resolution observations of naturally occurring ULF waves. During such experiments, the usually narrow radar spectral widths associated with artificial irregularities increase at times when small scale-sized (high m-number) ULF waves are observed. Possible mechanisms by which these particle-driven high-m waves may modify the observed spectral widths have been investigated. The results are found to be consistent with Pc1 (ion-cyclotron) wave activity, causing aliasing of the radar spectra, in agreement with previous modelling work. The observations also support recent suggestions that Pc1 waves may be modulated by the action of longer period ULF standing waves, which are simultaneously detected on the magnetospheric field lines. Drifting ring current protons with energies of ∼ 10keV are indicated as a common plasma source population for both wave types. Key words. Magnetospheric physics (MHD waves and instabilities) – Space plasma physics (wave-particle interactions) – Ionosphere (active experiments)

Lagrangian coherent structures deduced from HF radar measurements

2015 ◽  
Author(s):  
Francesco Enrile ◽  
Giovanni Besio ◽  
Marcello G. Magaldi ◽  
Carlo Mantovani ◽  
Simone Cosoli ◽  
...  
Keyword(s):  
Coherent Structures ◽  
Hf Radar ◽  
Lagrangian Coherent Structures ◽  
Radar Measurements

scholarly journals On the fast movements of the thermosphere: an interpretation

2000 ◽  
Vol 18 (12) ◽  
pp. 1651-1656
Author(s):  
J. Lilensten ◽  
P. O. Amblard
Keyword(s):  
Rotation Velocity ◽  
Atmospheric Composition ◽  
Neutral Wind ◽  
Typical Size ◽  
F Region ◽  
Optical Experiment ◽  
Atmospheric Composition And Structure ◽  
Composition And Structure ◽  
Eiscat Radar

Abstract. We examine the oscillations of the meridional neutral wind in the F region as seen by the EISCAT radar. We propose an interpretation in term of eddies (tourbillons) of typical size of a few tens to a few hundreds of kilometers. The observed rotation velocity is a few hundreds of meters per second. We suggest that the tourbillons are a common feature of thermospheric movements. We propose an optical experiment to check the validity of this assumption.Key words: Atmospheric composition and structure (thermosphere · composition and chemistry) · Ionosphere (ionosphere · atmosphere interactions)

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