A direction finding ionosonde for ionospheric propagation research

Black, Q. R.; Wood, J. F.; Sonsteby, A. G.; Sherrill, William M.

doi:10.1029/93rs00690

Cited by 14 publications

(4 citation statements)

References 19 publications

(9 reference statements)

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“…Determination of group path delay, 6 dB dispersion bandwidth, direction finding, and real height analysis from measurements of ionosondes plays an important role in channel characterization [ Salous , 1997, 1986, 1994; Goodman , 1992; Fox and Blundell , 1989; Black et al , 1993; Reilly and Kolesar , 1989; Lynn , 1998]. However, current scaling algorithms cannot provide all the parameters, and they are mostly operated manually (or at least require operator intervention) [ Poole and Mercer , 1995; Vugmeister and Radionov , 1995].…”

Section: Proposed Methods For Generation and Analysis Of Ionogramsmentioning

confidence: 99%

A new algorithm for high‐quality ionogram generation and analysis

Arıkan

Salous

2002

Radio Science

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Standard digital ionograms that are generated by fast Fourier transform or autoregressive modeling suffer from high interference levels due to other users of the HF channel which produce artifacts and distortion, hence complicating automatic processing and information extraction. In this paper, a new method is proposed to obtain high‐quality ionograms of the desired layer reflections and automatically extract important information such as critical frequencies. Following the standard procedures, two sets of periodograms are obtained by using rectangular and Blackman windows. These two periodograms are filtered and fused utilizing an automatic edge‐detection‐based time‐frequency detector. The fused ionogram provides sharp description of the layer reflections with very low sidelobe structure (ringing). The performance of this new ionogram algorithm is tested using chirp sounder data collected from an oblique midlatitude path. It is observed that the presented algorithm is highly successful in obtaining robust and sharp ionograms free of artifacts. Furthermore, a new algorithm is proposed for automated computation of dispersion and critical frequencies of the magnetoionic components detected on the ionogram. Since efficient signal‐processing algorithms are utilized, the proposed method can be implemented in real time.

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Section: Proposed Methods For Generation and Analysis Of Ionogramsmentioning

confidence: 99%

A new algorithm for high‐quality ionogram generation and analysis

Arıkan

Salous

2002

Radio Science

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“…While there exist a number of commercially available vertical incidence sounders with an AoA and/or Doppler capability, for example, the Lowell Digisonde (Reinisch et al, 2009) and Dynasonde (Rietveld et al, 2008), such systems are not as common for one-way oblique incidence as they require comparatively large arrays. Many earlier oblique experiments (e.g., Rice, 1973;Sherrill & Smith, 1977;Sweeney, 1970) focused on AoA observations over narrow frequency channels only, although several more modern studies have collected oblique AoA soundings over the full HF band (e.g., Black et al, 1993;Rogers et al, 2003;Sherrill & Brown, 1997;Vertogradov et al, 2013;Wright & Kressman, 1983). For the ELOISE campaign, a new AoA sounding system was built using DST Group's direct-digital HF transmitter (DOTS) and receiver (DORS) designs, which employ a low-power (20 W) wideband chirp waveform to function as a high-fidelity OIS (Gardiner-Garden et al, 2008, 2011.…”

Section: Array Design and Calibrationmentioning

confidence: 99%

Observations and Modeling of Traveling Ionospheric Disturbance Signatures From an Australian Network of Oblique Angle‐of‐Arrival Sounders

et al. 2018

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A network of oblique angle‐of‐arrival (AoA) ionosondes was installed as part of the Elevation‐scanned Oblique Incidence Sounder Experiment (ELOISE) in September 2015. The ELOISE experimental campaign was designed to study the spatial and temporal structure of ionospheric variability at midlatitudes, of which traveling ionospheric disturbances are a key component. The new AoA sounder makes use of Defence Science and Technology Group's direct‐digital high‐frequency transmitter and receiver technology, to enable multichannel collection of both ionograms and channel scattering functions (Doppler spectra) on a common 2‐D array. In this paper, the array design and onboard signal processing for the AoA sounder is described, along with a sample of results showing typical disturbance signatures across the delay, Doppler frequency, bearing, and elevation measurements. Realistic parameterized models of electron density perturbations, along with geometric ray tracing, were used to synthesize the effects of medium‐ to large‐scale traveling ionospheric disturbances on the sounder observables and aid in interpreting the measured signatures.

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“…DOA estimation has many applications in radar [ Haykin , 1985], sonar, seismology [ Bohme , 1995], and ionospheric research [ Black et al , 1993]. The performance of the direction finding (DF) system is significantly dependent to sensor array geometry.…”

Section: Introductionmentioning

confidence: 99%

Uniform and nonuniform V‐shaped planar arrays for 2‐D direction‐of‐arrival estimation

Filik

Tuncer

2009

Radio Science

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[1] In this paper, isotropic and directional uniform and nonuniform V-shaped arrays are considered for azimuth and elevation direction-of-arrival (DOA) angle estimation simultaneously. It is shown that the uniform isotropic V-shaped arrays (UI V arrays) have no angle coupling between the azimuth and elevation DOA. The design of the UI V arrays is investigated, and closed form expressions are presented for the parameters of the UI V arrays and nonuniform V arrays. These expressions allow one to find the isotropic V angle for different array types. The DOA performance of the UI V array is compared with the uniform circular array (UCA) for correlated signals and in case of mutual coupling between array elements. The modeling error for the sensor positions is also investigated. It is shown that V array and circular array have similar robustness for the position errors while the performance of UI V array is better than the UCA for correlated source signals and when there is mutual coupling. Nonuniform V-shaped isotropic arrays are investigated which allow good DOA performance with limited number of sensors. Furthermore, a new design method for the directional V-shaped arrays is proposed. This method is based on the Cramer-Rao Bound for joint estimation where the angle coupling effect between the azimuth and elevation DOA angles is taken into account. The design method finds an optimum angle between the linear subarrays of the V array. The proposed method can be used to obtain directional arrays with significantly better DOA performance.Citation: Filik, T., and T. E. Tuncer (2009), Uniform and nonuniform V-shaped planar arrays for 2-D direction-of-arrival estimation, Radio Sci., 44, RS5006,

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A direction finding ionosonde for ionospheric propagation research

Cited by 14 publications

References 19 publications

A new algorithm for high‐quality ionogram generation and analysis

A new algorithm for high‐quality ionogram generation and analysis

Observations and Modeling of Traveling Ionospheric Disturbance Signatures From an Australian Network of Oblique Angle‐of‐Arrival Sounders

Uniform and nonuniform V‐shaped planar arrays for 2‐D direction‐of‐arrival estimation

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