scholarly journals Elevation angle-of-arrival determination for a standard and a modified superDARN HF radar layout

Radio Science ◽  
2013 ◽  
Vol 48 (6) ◽  
pp. 709-721 ◽  
Author(s):  
Andrew J. McDonald ◽  
James Whittington ◽  
Sebastien de Larquier ◽  
Edhem Custovic ◽  
Thomas A. Kane ◽  
...  
Keyword(s):  
Elevation Angle ◽  
Hf Radar ◽  
Angle Of Arrival

scholarly journals Mapping ionospheric backscatter measured by the SuperDARN HF radars – Part 2: Assessing SuperDARN virtual height models

2008 ◽  
Vol 26 (4) ◽  
pp. 843-852 ◽  
Author(s):  
T. K. Yeoman ◽  
G. Chisham ◽  
L. J. Baddeley ◽  
R. S. Dhillon ◽  
T. J. T. Karhunen ◽  
...  
Keyword(s):  
Large Scale ◽  
Elevation Angle ◽  
Field Measurements ◽  
Companion Paper ◽  
Hf Radar ◽  
Propagation Path ◽  
Angle Of Arrival ◽  
Virtual Height ◽  
F Region ◽  
Propagation Paths

Abstract. The Super Dual Auroral Radar Network (SuperDARN) network of HF coherent backscatter radars form a unique global diagnostic of large-scale ionospheric and magnetospheric dynamics in the Northern and Southern Hemispheres. Currently the ground projections of the HF radar returns are routinely determined by a simple rangefinding algorithm, which takes no account of the prevailing, or indeed the average, HF propagation conditions. This is in spite of the fact that both direct E- and F-region backscatter and 1½-hop E- and F-region backscatter are commonly used in geophysical interpretation of the data. In a companion paper, Chisham et al. (2008) have suggested a new virtual height model for SuperDARN, based on average measured propagation paths. Over shorter propagation paths the existing rangefinding algorithm is adequate, but mapping errors become significant for longer paths where the roundness of the Earth becomes important, and a correct assumption of virtual height becomes more difficult. The SuperDARN radar at Hankasalmi has a propagation path to high power HF ionospheric modification facilities at both Tromsø on a ½-hop path and SPEAR on a 1½-hop path. The SuperDARN radar at Þykkvibǽr has propagation paths to both facilities over 1½-hop paths. These paths provide an opportunity to quantitatively test the available SuperDARN virtual height models. It is also possible to use HF radar backscatter which has been artificially induced by the ionospheric heaters as an accurate calibration point for the Hankasalmi elevation angle of arrival data, providing a range correction algorithm for the SuperDARN radars which directly uses elevation angle. These developments enable the accurate mappings of the SuperDARN electric field measurements which are required for the growing number of multi-instrument studies of the Earth's ionosphere and magnetosphere.

scholarly journals Optical, radar, and magnetic observations of magnetosheath plasma capture during a positive IMF <I>B<sub>z</sub></I> impulse

2008 ◽  
Vol 26 (3) ◽  
pp. 517-531 ◽  
Author(s):  
V. Safargaleev ◽  
A. Kozlovsky ◽  
T. Sergienko ◽  
T. K. Yeoman ◽  
M. Uspensky ◽  
...  
Keyword(s):  
Frequency Band ◽  
Elevation Angle ◽  
Spectral Width ◽  
Hf Radar ◽  
Doppler Spectrum ◽  
Angle Of Arrival ◽  
Radar Backscatter ◽  
Data Set ◽  
Ionospheric Plasma Density ◽  
Auroral Arcs

Abstract. We present a multi-instrument study of the ionospheric response to a northward turning of the IMF. The observations were made in the near-noon (11:00 MLT) sector on Svalbard (at 75° MLAT). The data set includes auroral observations, ionospheric flows obtained from the EISCAT and CUTLASS radars, the spectral width of the HF radar backscatter, particle precipitation and plasma flow data from the DMSP F13 satellite, and Pc1 frequency band pulsations observed by induction magnetometers. Careful collocation of all the observations has been made with the HF radar backscatter located by a ray-tracing procedure utilizing the elevation angle of arrival of the signals and an ionospheric plasma density profile. Prior to IMF turning northward, three auroral arcs were observed at the poleward boundary of the closed llbl, inside the llbl, and in the equatorward part of the llbl, respectively. The northward IMF turning was accompanied by enhanced HF radar returns with a broad Doppler spectrum collocated with the arcs. The auroral arcs shifted poleward whereas the backscatter region moved in the opposite direction, which is consistent, respectively, with reconnection beyond the cusp and the capturing of magnetosheath plasma during northward IMF. Locally, magnetic noise enhancement in the Pc1 frequency band occurred simultaneously with the anomalous radar backscatter, and the absence of such signals at more remote magnetic observatories indicates a local generation of the Pc1 turbulence, which is collocated with the radar backscatter. Finally, we discuss possible interpretation errors which may be caused by limited observational data.

scholarly journals Effects of high-latitude atmospheric gravity wave disturbances on artificial HF radar backscatter

2006 ◽  
Vol 24 (9) ◽  
pp. 2347-2361 ◽  
Author(s):  
A. Senior ◽  
M. J. Kosch ◽  
T. K. Yeoman ◽  
M. T. Rietveld ◽  
I. W. McCrea
Keyword(s):  
Pump Wave ◽  
Temporal Structure ◽  
Elevation Angle ◽  
Hf Radar ◽  
Angle Of Arrival ◽  
Atmospheric Gravity Wave ◽  
Radar Backscatter ◽  
Wave Disturbances ◽  
Spatio Temporal ◽  
Atmospheric Gravity

Abstract. Observations of HF radar backscatter from artificial field-aligned irregularities in an ionosphere perturbed by travelling disturbances due to atmospheric gravity waves are presented. Some features of the spatio-temporal structure of the artificial radar backscatter can be explained in terms of the distortion of the ionosphere resulting from the travelling disturbances. The distorted ionosphere can allow the HF pump wave to access upper-hybrid resonance at larger distances from the transmitter than are normally observed and can also prevent the pump wave reaching this resonance at close distances. The variation in altitude of the irregularities sometimes results in a significant variation in the elevation angle of arrival of the backscattered signal at the radar implying that the radar "sees" a target moving in altitude. We suggest that this may be evidence of off-orthogonal scattering from the irregularities.

scholarly journals Mapping ionospheric backscatter measured by the SuperDARN HF radars – Part 1: A new empirical virtual height model

2008 ◽  
Vol 26 (4) ◽  
pp. 823-841 ◽  
Author(s):  
G. Chisham ◽  
T. K. Yeoman ◽  
G. J. Sofko
Keyword(s):  
Elevation Angle ◽  
Propagation Path ◽  
Angle Of Arrival ◽  
Velocity Measurements ◽  
Actual Distribution ◽  
Virtual Height ◽  
Radar Network ◽  
Straight Line ◽  
Target Locations ◽  
Height Model

Abstract. Accurately mapping the location of ionospheric backscatter targets (density irregularities) identified by the Super Dual Auroral Radar Network (SuperDARN) HF radars can be a major problem, particularly at far ranges for which the radio propagation paths are longer and more uncertain. Assessing and increasing the accuracy of the mapping of scattering locations is crucial for the measurement of two-dimensional velocity structures on the small and meso-scale, for which overlapping velocity measurements from two radars need to be combined, and for studies in which SuperDARN data are used in conjunction with measurements from other instruments. The co-ordinates of scattering locations are presently estimated using a combination of the measured range and a model virtual height, assuming a straight line virtual propagation path. By studying elevation angle of arrival information of backscatterred signals from 5 years of data (1997–2001) from the Saskatoon SuperDARN radar we have determined the actual distribution of the backscatter target locations in range-virtual height space. This has allowed the derivation of a new empirical virtual height model that allows for a more accurate mapping of the locations of backscatter targets.

ICEBEAR: Recent Results from a Bistatic Coded Continuous-Wave E-region Coherent Scatter Radar

2020 ◽  
Author(s):  
Devin Huyghebaert ◽  
Adam Lozinsky ◽  
Glenn Hussey ◽  
Kathryn McWilliams ◽  
Draven Galeschuk ◽  
...  
Keyword(s):  
Plasma Density ◽  
Continuous Wave ◽  
Random Noise ◽  
Azimuthal Angle ◽  
Elevation Angle ◽  
Field Of View ◽  
Angle Of Arrival ◽  
Coherent Scatter ◽  
Scatter Radar ◽  
E Region

&lt;p&gt;The Ionospheric Continuous-wave E-region Bistatic Experimental Auroral Radar (ICEBEAR) is located in Canada and has a field of view centered at (58&amp;#176;N, 106&amp;#176;W) overlooking the terrestrial auroral zone. &amp;#160;This 49.5 MHz coherent scatter radar measures plasma density irregularities in the E-region ionosphere using a pseudo random noise phase modulated continuous-wave (CW) signal. &amp;#160;ICEBEAR uses this coded CW signal to obtain simultaneous high temporal (1 s) and spatial (1.5 km) resolutions of E-region plasma density turbulence over a 600 km x 600 km field of view, providing insights into the Farley-Buneman plasma density instability and wave-like structures evident in the coherent scatter. &amp;#160;The initial results from ICEBEAR were obtained with a 1D receiving array, providing azimuthal angle of arrival details of the incoming scattered signal. &amp;#160;This azimuthal determination, along with the range determined using the coded signal, allowed the scatter to be mapped in 2D. &amp;#160;A recent reconfiguration of the receiving array has allowed the elevation angle of the received signal to be calculated, providing 3D determination of the location of the plasma density irregularities. &amp;#160;This presentation will demonstrate the capabilities of ICEBEAR, displaying measurements of highly dynamic plasma density irregularities with wave-like behaviour on 1 second time scales.&lt;/p&gt;

scholarly journals The Impact of Antenna Height on 3D-MIMO Channel: a Ray Launching Based Analysis

2017 ◽  
Author(s):  
Qi Hong ◽  
Jiliang Zhang ◽  
Hui Zheng ◽  
Hao Li ◽  
Haonan Hu ◽  
...  
Keyword(s):  
Channel Model ◽  
Elevation Angle ◽  
Base Station ◽  
Mimo Channel ◽  
Delay Spread ◽  
Three Dimension ◽  
Angle Of Arrival ◽  
3D Mimo ◽  
The Impact ◽  
Ray Launching

Three dimension (3D) Multi-input-multi-output (MIMO) scheme, which exploits another dimension of the spatial resource, is one of the enabling technologies for the next generation mobile communication. As the elevation angle in 3D-MIMO channel model might varies against the height of the base station transmit antenna, it has to be taken into account carefully. In this paper, the impact of antenna height on the channel characteristics of 3D MIMO channel is investigated by using the intelligent ray launching algorithm (IRLA). Three typical street scenarios, i.e., the straight street, the fork road and the cross road, are selected as benchmarks. On the basis of simulations, joint and marginal probability density functions (PDFs) of both the elevation angle of departure (EAoD) and the elevation angle of arrival (EAoA) are obtained. The elevation angle spread (AS) and the delay spread (DS) under various antenna heights are also discussed. Simulation results indicate that the PDFs of EAoD and EAoA vary characteristics under different street scenarios. Moreover, the minimum value of the DS can be achieved when the antenna height is half of the building height.

scholarly journals Calibrating HF Radar Elevation Angle Measurements Using E  Layer Backscatter Echoes

Radio Science ◽  
2018 ◽  
Vol 53 (11) ◽  
pp. 1438-1449 ◽  
Author(s):  
P. Ponomarenko ◽  
J.‐P. St.‐Maurice ◽  
K. A. McWilliams
Keyword(s):  
Elevation Angle ◽  
Hf Radar ◽  
Angle Measurements

Root-MUSIC-based azimuth-elevation angle-of-arrival estimation with uniformly spaced but arbitrarily oriented velocity hydrophones

1999 ◽  
Vol 47 (12) ◽  
pp. 3250-3260 ◽  
Author(s):  
K.T. Wong ◽  
M.D. Zoltowski
Keyword(s):  
Elevation Angle ◽  
Angle Of Arrival
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