Deterministic retrieval of ionospheric phase screen from amplitude scintillations

Abstract

Abstract. In the phase screen theory of ionospheric scintillations the ionospheric irregularities are considered as pure phase objects, and the diffraction pattern produced on the ground, by radio waves propagating through this phase screen, is obtained from conventional Fresnel diffraction theory. In the present paper the inverse problem of retrieving phase variations in the screen from the diffraction pattern on the ground is treated by using the transport-of-intensity equation (TIE), which is derived from the Fresnel diffraction theory result. An approximate version of the TIE is solved to obtain the phase variation in the screen from the intensity distribution on the ground. It is seen that when the phase variations involve spatial scale lengths ,,,400 m, phase fluctuations of •,5 tad can be recovered from intensity variations on the ground, for a 300-MHz signal. For larger spatial scale lengths and higher frequencies this method can be used to retrieve larger phase variations in the screen.

Effects of Solar Radio Emission and Ionospheric Irregularities on GPS/GLONASS Performance

“…The rms of error for the dynamic stress of the receiver is where dR 3 /dt 3 is the maximum dynamic stress of the receiver along the "satellite-receiver" line of sight. Expressions (11) and (12) are written for the third-order loop filter which is typically used for signal phase tracking in navigation receivers.…”

“…In the phase-screen approximation, variations in the signal phase and amplitude at the receiving point are interconnected (Bhattacharyya, 1999):…”

Low frequency modulation of transionospheric radio wave amplitude at low-latitudes: possible role of field line oscillations

“…Radio waves scattered by small-scale irregularities with scales typically less than the Fresnel scale (Bhattacharyya, 1999) form a diffraction pattern on the ground and as the irregularities drift in space, the received signals at a fixed station 'scintillate' with a time scale of a fraction of seconds with amplitudes (depth of scintillations) of the order of the received signal itself. The diffraction pattern on the ground is often treated under the phase screen approximation.…”

Customer selection for direct marketing: bi-objective optimization using support vector machine

“…These techniques include but are not limited to decision tree, neural networks, and evolutionary algorithm. Decision tree Haughton and Oulabi (1997), Ling and Li (1998), Freund and Schapire (1996) Artificial neural networks Zahavi and Levin (1997), Gruca et al (1999), Kim and Street (2004), Ha et al (2005), Kim et al (2005), Shin and Sohn (2004) Evolutionary algorithm Yu et al (2005), Bhattacharyya (1998), Bhattacharyya(1999), Bhattacharyya(2000), Dou et al (2008)…”

“…Then Bhattacharyya (1999) presents a GA based approach for obtaining models with explicit consideration of the mailing depth and performs experiments based on a real-life data set. Bhattacharyya (2000) proposes the use of evolutionary computation based procedures for obtaining a set of non-dominated models with respect to multiple stated objectives.…”