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Plasma Line Measurements At Chatanika With High-Speed Correlator And Filter Bank, W. Kofman, Vincent B. Wickwar
Plasma Line Measurements At Chatanika With High-Speed Correlator And Filter Bank, W. Kofman, Vincent B. Wickwar
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In the spring and fall of 1978 we made an extensive series of plasma line and correlative observations with the Chatanika incoherent scatter radar. To make these measurements, we greatly modified the radar receiving system. In addition to enlarging the plasma line filter bank the most significant change was the incorporation of a high-speed correlator provided by the French. This was the first use of a correlator in a monostatic radar to obtain the intensity spectra of naturally occurring plasma lines. In this paper we develop the signal-processing theory that we use to obtain the plasma line intensities from these …
High-Latitude Convection: Comparison Of A Simple Model With Incoherent Scatter Observations, Jan Josef Sojka, J. C. Foster, W. J. Raitt, Robert W. Schunk, J. R. Doupnik
High-Latitude Convection: Comparison Of A Simple Model With Incoherent Scatter Observations, Jan Josef Sojka, J. C. Foster, W. J. Raitt, Robert W. Schunk, J. R. Doupnik
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We have compared a simple model of plasma convection at high latitudes with data obtained from simultaneous measurements made by the incoherent scatter facilities at Chatanika, Alaska and Millstone Hill, Massachusetts in June 1978 during moderately disturbed conditions. The measured horizontal plasma drift velocities were averaged for four days to emphasize gross features of the convection pattern and reduce the effects of substorms. The convection model includes the offset of 11.5° between the geographic and geomagnetic poles, the tendency of plasma to corotate about the geographic pole, and a constant dawn/dusk magnetospheric electric field mapped to a circle about a …
A Comparison Of Model Predictions For Plasma Convection In The Northern And Southern Polar Regions, Jan Josef Sojka, W. J. Raitt, Robert W. Schunk
A Comparison Of Model Predictions For Plasma Convection In The Northern And Southern Polar Regions, Jan Josef Sojka, W. J. Raitt, Robert W. Schunk
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We have presented model calculations to show how the plasma flow distributions in the northern and southern polar regions differ when viewed from a geographic inertial frame. This reference frame was selected because it is the natural frame for geophysical plasma flow measurements, there being well-known velocity corrections for either satellite or ground-based observations. Although the magnetic invariant latitude, magnetic local time reference frame is better suited to studying magnetospheric processes, a transformation from the geographic inertial frame to this magnetic frame requires both a spatial and velocity transformation, and since the latter correction has generally been neglected, we prefer …