Radio-frequency imaging techniques for ionospheric, magnetospheric, and planetary studies

Fung, S. F.; Benson, Robert F.; Galkin, I. A.; Green, James L.; Reinisch, B. W.; Song, P.; Sonwalkar, V. S.

doi:10.1016/b978-0-12-820630-0.00006-4

Cited by 5 publications

(4 citation statements)

References 233 publications

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“…Very few VLF transmitters have actually been flown (e.g., Fung et al., 2022). In 1987, the Progress‐28 transport vehicle demonstrated a successful VLF space‐to‐space transmission to the Mir orbital station (Armand et al., 1988).…”

Section: Historical Reference: Vlf Transmission In Space Plasmasmentioning

confidence: 99%

The VLF Transmitter, Narrowband Receiver, and Tuner Investigation on the DSX Spacecraft

et al. 2023

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Background and MotivationUnderstanding, specification, and mitigation of the geomagnetically trapped radiation effects on human activity in space have been topics of intense interest since the discovery of the Van Allen belts in 1958, for example, Song et al. (2001). Concerns about damage to Earth-orbiting satellite systems and humans in space have led to studies of ways such threats may be mitigated through controlled precipitation of energetic electrons from the radiation belts (Kennel & Petschek, 1966). Loss of energetic electrons from the radiation belts is known to occur as a result of Doppler-shifted gyro-resonance interactions with in situ VLF, or physically, whistler-mode waves, examples being scattering by lightning-generated whistlers, magnetospheric activity-related whistler-triggered wave bursts, bursts of natural whistler-mode noise, and whistler-mode signals from high-power ground-based VLF communication transmitters (Abel & Thorne, 1998;Imhof et al., 1983). Here we note that the whistler mode may cover

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Section: Historical Reference: Vlf Transmission In Space Plasmasmentioning

confidence: 99%

The VLF Transmitter, Narrowband Receiver, and Tuner Investigation on the DSX Spacecraft

et al. 2023

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“…However, it is very difficult to measure in situ n e directly due to the varying spacecraft potential that may distort the ambient plasma density count provided by onboard particle sensors (e.g., Pfaff et al., 1998). Radio wave instruments such as the low‐power resonance relaxation sounder (e.g., Fung et al., 2022) that detect plasma responses at characteristic frequencies (plasma f pe , cyclotron harmonics n f ce , and the upper hybrid f uh =

\sqrt{{f}_{\text{pe}}^{2}+{f}_{\text{ce}}^{2}}

) are less susceptible to the spacecraft‐induced effects. The long‐duration responses are attributed to slowly propagating electrostatic waves (Muldrew, 1972) reaching out 1,000+ meters into the surrounding plasma where instrument effects are negligible.…”

Section: Introductionmentioning

confidence: 99%

Electron Density Specification in the Inner Magnetosphere From the Narrow Band Receiver Onboard DSX

Su,

Carilli,

Parham

et al. 2024

Radio Science

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Electron density plays an important role in the study of wave propagation and is known to be associated with the index of refraction and radiation belt diffusion coefficients. The primary objective of our investigation is to explore the possibility of implementing an onboard signal processing algorithm to automatically obtain electron densities from the upper hybrid resonance traces of wave spectrograms for future missions. U‐Net, developed for biomedical image segmentation, has been adapted as our deep learning architecture with results being compared with those extracted from a more traditional semi‐automated method. As a product, electron densities and cyclotron frequencies for the entire DSX mission between 2019 and 2021 are acquired for further analysis and applications. Due to limited space measurements, a synthetic image generator based on data statistics and randomization is proposed as an initial step toward the development of a generative adversarial network in hopes of providing unlimited realistic data sources for advanced machine learning.

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“…MSTIDs are usually responsible for variations of tenths of TECu, but they can reach up to a few TECu during solar maximum (Hernández-Pajares et al, 2006 and they can also cause an increase in cycle slip occurrence (Poniatowski & Nykiel, 2020). TIDs are sometimes regarded as a "silent killer of accuracy" or "short-range catastrophe" (Fung et al, 2022) as they are hardly detectable when they affect the GNSS signals received on the ground. TIDs are considered a major nuisance for any system using trans-ionospheric radio wave propagation in the mid-latitude regions (Belehaki et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Travelling ionospheric disturbances detection: A statistical study of detrending techniques, induced period error and near real-time observables

Guerra,

Cesaroni,

Ravanelli

et al. 2024

J. Space Weather Space Clim.

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Due to advances in remote sensing of the Earth's Ionosphere through Total Electron Content (TEC) estimates by Global Navigation Satellite System (GNSS) receivers, it is possible to detect and characterize Travelling Ionospheric Disturbances (TIDs) in both post-processing and, to some extent, in near real-time (NRT). A reliable and precise TEC filtering technique must be adopted to characterize waves accurately. Specifically, TEC detrending is widely adopted to extract the amplitude and period of the detected ionospheric waves from the background ionospheric conditions. Therefore, this study aims to understand and compare how different TEC detrending techniques and their settings impact the ability to extract such parameters. We highlight that the novel Fast Iterative Filtering (FIF) and the Savitzky-Golay filter (SGOLAY) techniques are the most reliable overall compared with moving average (MA), multi-order numerical difference (DD), polynomial detrending (POLY) and Finite Impulse response (FIR) band-pass filter (BUTF). Moreover, the impact of general algorithm settings on the extracted TID period is investigated, such as the Ionospheric Piercing Point (IPP) height and elevation cut-off angle, showing that such parameters drastically impact the retrieved period, especially for slower TIDs. Finally, due to the growing interest in real-time (RT) detection and classification of TIDs, the study proposes techniques for accurately estimating the TID amplitude in an NRT scenario. Such NRT techniques are then compared with the widely used post-processing products, such as the calibrated vertical TEC (vTEC), showing a difference that is mostly lower than the typical noise level of GNSS receivers (0.05 TECu).

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Radio-frequency imaging techniques for ionospheric, magnetospheric, and planetary studies

Cited by 5 publications

References 233 publications

The VLF Transmitter, Narrowband Receiver, and Tuner Investigation on the DSX Spacecraft

The VLF Transmitter, Narrowband Receiver, and Tuner Investigation on the DSX Spacecraft

Electron Density Specification in the Inner Magnetosphere From the Narrow Band Receiver Onboard DSX

Travelling ionospheric disturbances detection: A statistical study of detrending techniques, induced period error and near real-time observables

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