A radio frequency electron density probe for rocket investigation of the ionosphere

MacKenzie, E.C.; Sayers, Jentery

doi:10.1016/0032-0633(66)90103-6

Cited by 14 publications

(4 citation statements)

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“…-En plus du vecteur position x nous utiliserons les grandeurs c = (m/2 kTe)1/2 w et qJ = -eV/kTe , (A. 1) où w est le vecteur vitesse et V le potentiel. Pour le régime stationnaire, l'équation de Vlasov s'écrit :…”

Section: Appendice Iunclassified

“…Introduction. -Une sonde, destinée à mesurer la densité électronique dans l'ionosphère et conçue par le Professeur Sayers [1 ], a été utilisée à bord du satellite FR-1. Les résultats obtenus [2] n'ont pu jusqu'à présent être interprétés, ce qui nécessite d'approfondir l'étude du comportement de cette sonde.…”

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“…D'après ce qui précède, le courant alternatif décroît depuis les potentiels négatifs jusqu'au potentiel plasma. Si l'on excepte l'interprétation erronée des premiers travaux [1 ], Sayers et al [3] se bornent à affirmer qu'au-delà du potentiel plasma, la vitesse moyenne des particules croît, donc leur densité décroît dans la région de la sonde. Le courant alternatif mesuré aux bornes du condensateur passerait alors par un minimum au potentiel plasma.…”

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Diagnostic d'un faisceau de plasma autour d'un corps positif et application à la sonde de sayers

Fournier

1973

Rev. Phys. Appl. (Paris)

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Reçu le 14 février 1973)Résumé. -On analyse la constitution des gaines autour d'un corps polarisé positivement en vol ionosphérique. Ces résultats permettent d'expliquer les difficultés de mise en oeuvre de la sonde de Sayers destinée à mesurer la densité électronique.Abstract. 2014 Space-charge sheaths of positively biased bodies in ionospheric flight are analyzed. These results explain the difficulties encountered in using the Sayers' electron-density probe.

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Section: Appendice Iunclassified

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Diagnostic d'un faisceau de plasma autour d'un corps positif et application à la sonde de sayers

Fournier

1973

Rev. Phys. Appl. (Paris)

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“…However, such measurement campaigns are limited in their geographic coverage and may also be limited in their vertical resolution. The high-resolution vertical structure of Es has been studied using sounding rockets (Aubry et al, 1966;MacKenzie & Sayers, 1966;Wakabayashi et al, 2005). However, such measurements are even more geographically sparse.…”

Section: Introductionmentioning

confidence: 99%

Semi-supervised classification of lower-ionospheric perturbations using GNSS radio occultation observations from Spire Global’s Cubesat Constellation

Savastano¹,

Nordstrom²,

Angling³

2022

J. Space Weather Space Clim.

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In this study, we present a new methodology to automatically classify perturbations in the lower ionosphere using GNSS radio occultation (RO) observations collected using Spire’s constellation of CubeSats. This methodology combines signal processing techniques with semi-supervised machine learning by applying spectral clustering in a metric space of wavelet spectra. A “bottom-up” algorithm was applied to extract E layer information directly from Spire’s high-rate (50 Hz) GNSS-RO profiles by subtracting the effect of the F layers. This processing algorithm has been implemented in our ground segment to operationally produce high rate sTEC profiles with a vertical resolution of better than 100 m. The key idea behind the semi-supervised classification is to produce a database of labeled clusters that can be used to classify new unlabeled data by determining which cluster it belongs to. A dataset of more than 12000 GNSS-RO profiles collected in 2019 containing sTEC perturbations is used to find the initial clusters. This dataset is used as a representation of the climatology of ionospheric perturbations, such as MSTIDs and sporadic Es. The wavelet power spectrum (WPS) is computed for these profiles, and a metric space is defined using the Earth mover's distance (EMD) between the WPS. A self-tuning spectral clustering algorithm is used to cluster the profiles in this metric space. These clusters are used as a reference database of perturbations to classify new sTEC profiles by finding the cluster of the closest profile of the clustered dataset in the EMD metric space. This new methodology is used to construct an automated system to monitor ionospheric perturbations on a global scale.

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Radio-frequency impedance probes

Kaiser

Tunaley

1968

Space Science Reviews

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A radio frequency electron density probe for rocket investigation of the ionosphere

Cited by 14 publications

References 3 publications

Diagnostic d'un faisceau de plasma autour d'un corps positif et application à la sonde de sayers

Diagnostic d'un faisceau de plasma autour d'un corps positif et application à la sonde de sayers

Semi-supervised classification of lower-ionospheric perturbations using GNSS radio occultation observations from Spire Global’s Cubesat Constellation

Radio-frequency impedance probes

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