Browsing by Author "Pomalaza, J."

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    Equion, an equatorial ionospheric irregularity experiment
    (American Geophysical Union, 1977-02-01) Morse, F. A.; Edgar, B.C.; Koons, H. C.; Rice, C. J.; Heikkila, W. J.; Hoffman, J. H.; Tinsley, B. A.; Winningham, J. D.; Christensen, A. B.; Woodman Pollitt, Ronald Francisco; Pomalaza, J.; Teixeira, N. R.
    This paper describes a coordinated rocket and ground‐based study to investigate equatorial spread F irregularities. Measurements by the Jicamarca backscatter radar, ionosondes, and airglow instrumentation and of radio scintillations were correlated with high spatial resolution measurements of electron densities, particle fluxes, and VLF‐ELF fields from a rocket probe. Experimentally, we find that (1) very high positive and negative electron density gradients are responsible for the enhanced radar echoes, (2) energetic particles are not part of the spread F phenomena, (3) wave measurements are strongly correlated with the Doppler character of the radar signals, and (4) there is a one‐to‐one correspondence of the large‐scale irregularities responsible for scintillations of satellite radio transmissions and ionosonde spread echoes with the small‐scale irregularities responsible for the backscatter of VHF radar signals. We present and discuss the implications of the data.
    Palabras clave:IonosphereIncoherent scattering radarDoppler effect
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    Statistical study of equatorial scintillations at Ancon, Peru
    (Instituto Geofísico del Perú, 1970) Tisnado, G.; Woodman Pollitt, Ronald Francisco; Pomalaza, J.
    The 136 MHz interferometric system at the past NASA Satellite Track­ing Station in Ancón, Perú, consists of two orthogonal baselines aligned along the North-South and East-West directions. A sizable number of interferometric records intended far operation­al tracking was spoiled by large amplitude and phase fluctuations. Ir - regularities In the ionosphere, those associated with the spread-F phenomena, are the cause of these fluctuations (scintillations). In most of the distorted records the North-South baseline inter­ferometer shows only a slight distort(on from the expected satellite graph whlle in the East-West interferometer the distortions are severe. This clearly shows the anisotropy of the irregularities and that they are elongated and aligned the magnetic field lines(Z) as have been found by other authors. The absence of North-South phase distortions when East­West distortions are present facilitates the detection of weak scintillations against the background noise. Far the purpose of this report the East-West baseline interferometric distortion was taken as an indication of scintillations.
    Palabras clave:ScintillationInterferometryFluctuations