Analysis of data‐driven parametric models of the vertical ionospheric profile for use in oblique propagation studies

Barnes, Rod I.; Braendler, S. A.; Coleman, Christopher John; Gardiner-Garden, Robert S.; Hoang, Thong

doi:10.1029/98rs01754

Cited by 8 publications

(5 citation statements)

References 12 publications

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“…The proposed work uses the same principle as previous work [ Wright et al ., ; Barnes et al ., ; Pezzopane and Scotto , ; Scotto , 2009; Ding et al ., ; Vesnin et al ., ], but it improves the performance in several aspects. The QPS model is used to simplify the trace synthesis task.…”

Section: Introductionmentioning

confidence: 99%

“…The process described by Wright et al [1972] estimated the virtual heights coordinates at the specified optimum radio frequencies, and then selected the observations nearest the predicted coordinates from a subsequent digital ionogram. Barnes et al [1998] developed some estimation techniques to fit recorded ionograms, and the approach described by Barnes et al selected ARTIST-3 values as the initial values. Pezzopane and Scotto [2007] used simultaneous fit of O polarization and X polarization traces near critical frequency cusps using a template set of typical trace shapes.…”

Section: Introductionmentioning

confidence: 99%

“…Barnes et al . [] developed some estimation techniques to fit recorded ionograms, and the approach described by Barnes et al selected ARTIST‐3 values as the initial values. Pezzopane and Scotto [] used simultaneous fit of O polarization and X polarization traces near critical frequency cusps using a template set of typical trace shapes.…”

Section: Introductionmentioning

confidence: 99%

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An automatic scaling technique for obtaining F₂ parameters and F₁ critical frequency from vertical incidence ionograms

et al. 2013

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[1] Recent advances in computing technologies have renewed interest in the intelligent systems for automatic interpretation of ionograms, images obtained by remote sensing of the ionospheric plasma. The ionogram "autoscaling" techniques based on the template matching method, previously rendered unrealistic for their computing complexity, have now become feasible. This work presents an automatic scaling technique for extracting the main features of the F 1 and F 2 layers of the ionosphere, such as critical frequency and virtual height, from vertical incidence ionograms that do not distinguish O/X polarization of the echoes. The proposed technique uses the quasi-parabolic segments (QPS) to model the electron density profile shapes that are used to synthesize a pool of candidate traces. Moreover, the empirical orthogonal functions and image technique are applied to reduce the size of the candidate traces so that the auto-scaling algorithm can run in realistic time. With the template matching algorithm, the technique will provide the initial parameters of the QPS model for the F 1 and F 2 layers, which are then fine-tuned to obtain the better fitting parameters. In order to evaluate the performance of this technique, a large data set of ionograms recorded in Wuhan at daytime and nighttime in winter, summer, and equinoctial months, are analyzed and investigated. The automatic scaling results are compared with manually scaling results. Our results indicate that the proposed technique described in this paper is reliable and efficient and will facilitate the statistical study of temporal and spatial ionospheric characteristics over Wuhan.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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An automatic scaling technique for obtaining F₂ parameters and F₁ critical frequency from vertical incidence ionograms

et al. 2013

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“…The success of this compensation is dependent on the accuracy of the electron density profile used to perform the compensation. Ideally, the electron density profile could be provided by a co-located vertical incidence ionospheric sounder (VIS) [34] or a real-time ionospheric model (RTIM) [35,36]. However, for locations such as Buckland Park, where neither a VIS or RTIM is available, a climatological model such as the International Reference Ionosphere (IRI) must be used.…”

Section: Discussionmentioning

confidence: 99%

Space Domain Awareness Observations Using the Buckland Park VHF Radar

Holdsworth,

Spargo,

Reid

et al. 2024

Remote Sensing

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There is increasing interest in space domain awareness worldwide, motivating investigation of the use of non-traditional sensors for space surveillance. One such class of sensor is VHF wind profiling radars, which have a low cost relative to other radars typically applied to this task. These radars are ubiquitous throughout the world and may potentially offer complementary space surveillance capabilities to the Space Surveillance Network. This paper updates an initial investigation on the use of Buckland Park VHF wind profiling radars for observing resident space objects in low Earth orbit to further investigate the space surveillance capabilities of the sensor class. The radar was operated during the Australian Defence “SpaceFest” 2019 activity, incorporating new beam scheduling and signal processing functionality that extend upon the capabilities described in the initial investigation. The beam scheduling capability used two-line element propagations to determine the appropriate beam direction to use to observe transiting satellites. The signal processing capabilities used a technique based on the Keystone transform to correct for range migration, allowing the development of new signal processing modes that allow the coherent integration time to be increased to improve the SNR of the observed targets, thereby increasing the detection rate. The results reveal that 5874 objects were detected over 10 days, with 2202 unique objects detected, representing a three-fold increase in detection rate over previous single-beam direction observations. The maximum detection height was 2975.4 km, indicating a capability to detect objects in medium Earth orbit. A minimum detectable RCS at 1000 km of −10.97 dBm2 (0.09 m2) was observed. The effects of Faraday rotation resulting from the use of linearly polarised antennae are demonstrated. The radar’s utility for providing total electron content (TEC) measurements is investigated using a high-range resolution mode and high-precision ephemeris data. The short-term Fourier transform is applied to demonstrate the radar’s ability to investigate satellite rotation characteristics and monitor ionospheric plasma waves and instabilities.

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“…These sounders constantly monitor the ionosphere for the purpose of generating a near RTIM, which is required for the JORN coordinate registration system [23]. The RTIM is built from quasi-parabolic layers [24], [25] that parameterize the electron density profile. A 3-D grid of ionospheric electron densities with a temporal resolution of 5 min, and a spatial resolution of 1 • in latitude and longitude and 1 km height steps was constructed from the JORN RTIM parameters for the purpose of calculating the propagation losses described in Section II-C.…”

Section: B Real-time Ionospheric Modelmentioning

confidence: 99%

High Frequency Land Backscatter Coefficients Over Northern Australia and the Effects of Various Surface Properties

Edwards

Cervera

MacKinnon

2022

IEEE Trans. Antennas Propagat.

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Over-the-horizon radars (OTHRs) utilize the refractive properties of the ionosphere to illuminate targets beyond the Earth's horizon. Consequently, the performance of this type of radar is highly dependent on the ionosphere. Reliable models of the radar ground backscatter are required to accurately assess the ionospheric propagation conditions and, thus, the expected performance of OTHRs. The ground backscatter coefficient characterizes the amount of radiation scattered back from a surface toward a receiver per unit area. While the backscatter coefficient of the sea is well understood and may be calculated from theory if the sea state is known, the backscatter coefficient of land at high frequencies is not well understood. To calculate the land backscatter coefficients over Northern Australia, a methodology that compares observed backscatter ionograms to those synthesized using high-frequency (HF) radio wave raytracing techniques through model ionospheres was developed. Maps of the backscatter coefficients across Northern Australia were produced. The effects of surface properties, including topography, soil moisture, and vegetation cover on the backscatter coefficients, were investigated. A weak positive correlation between the backscatter coefficient and the soil moisture and surface roughness was observed; however, it was found that the vegetation had the largest effect on the backscatter coefficient.

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Analysis of data‐driven parametric models of the vertical ionospheric profile for use in oblique propagation studies

Cited by 8 publications

References 12 publications

An automatic scaling technique for obtaining F₂ parameters and F₁ critical frequency from vertical incidence ionograms

An automatic scaling technique for obtaining F₂ parameters and F₁ critical frequency from vertical incidence ionograms

Space Domain Awareness Observations Using the Buckland Park VHF Radar

High Frequency Land Backscatter Coefficients Over Northern Australia and the Effects of Various Surface Properties

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Analysis of data‐driven parametric models of the vertical ionospheric profile for use in oblique propagation studies

Cited by 8 publications

References 12 publications

An automatic scaling technique for obtaining F2 parameters and F1 critical frequency from vertical incidence ionograms

An automatic scaling technique for obtaining F2 parameters and F1 critical frequency from vertical incidence ionograms

Space Domain Awareness Observations Using the Buckland Park VHF Radar

High Frequency Land Backscatter Coefficients Over Northern Australia and the Effects of Various Surface Properties

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An automatic scaling technique for obtaining F₂ parameters and F₁ critical frequency from vertical incidence ionograms

An automatic scaling technique for obtaining F₂ parameters and F₁ critical frequency from vertical incidence ionograms