On ionospheric investigations by coherent radiowaves emitted from artificial Earth satellites

Abstract

Results of radio-investigations of the ionosphere with the help of coherent radiowaves emitted by beacons placed on artificial Earth satellites are given. The data discussed cover the period from 1958, after the launch of Sputniks I and 3, until the last years, when the geostationary satellites ATS were launched. It is shown that up to the present justice has not be done in these experiments to investigations of the local properties of the near Earth plasma. This is a great deficiency in this field of investigation. Data are given which illustrate results of investigations of local ionospheric characteristics. Such data may help to solve some problems in the present stage of the near Earth plasma study. A new possibility of radio-investigation of the near Earth plasma with the help of a chain of satellites connected together is pointed out.

Galileo E5 AltBOC Signals: Application for Single-Frequency Total Electron Content Estimations

“…Currently, there are 24 Galileo satellites continuously transmitting wideband E5 Al-tBOC signals, which can be used to estimate the ionospheric TEC via single-frequency combination (3). The number of receiving sites capable of working with that type of signal is also increasing.…”

“…Note that assuming DCBs are known/calibrated carrier leveling or code smoothing procedures can be applied to (1) and ( 2), providing absolute values of TEC, while due to unknown phase ambiguities, single-frequency combination (3) seems to be suitable for monitoring TEC changes rather than absolute TEC values. Nevertheless, the approach for resolving unknown constants in (3), which is quite similar to DCB estimation [34], could be adopted, making single-frequency relative TEC estimates quite useful for applications that require absolute TEC data.…”

“…To estimate TEC, scientists have suggested radio beacons which provide data on the Faraday rotation of the signal polarization plane [1] or the signal phase and pseudorange (group delay) [2,3]. The first approach requires geomagnetic field data along the line of sight and linearly polarized signals.…”

Doppler frequency shift of a wave propagating in a time‐varying, inhomogeneous, anisotropic medium

“…The quantities denoted by the small letters are space projections of those denoted by the capital letters. The previous authors [Schr6dinger, 1956;Kelso, 1960Kelso, , 1961Al'pert, 1964;Rawer, 1964;Kimura and Nishina, 1967;Holt, 1973] We have obtained the formula for the Doppler frequency shift on the basis of differential geometry. The formula thus obtained is general and we can apply it as long as the eikonal approximation makes sense.…”

“…The Doppler method is one of the most fundamental methods used in wave propagation experiments in the ionosphere. Several attempts have been made to obtain the general formula for the Doppler frequency shift in a time-varying, inhomogeneous, anisotropic medium [Kelso, 1960[Kelso, , 1961Al'pert, 1964;Rawer, 1964;Kirnura and Nishina, 1967;Holt, 1973. For a summary see the review by A l 'pert, 1976].…”