Browsing by Author "Villanueva, Fernando"

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    Comparison of electric fields measured at F-region heights with 150 km - irregularity drift measurements
    (Editor no identificado, 1995) Woodman Pollitt, Ronald Francisco; Villanueva, Fernando
    The potential to observe the E-W electric field in the equatorial ionosphere using the strong coherent echoes obtained by the Jicamarca radar from irregularities present at the Magnetic Equator, in the altitude range between 135 and 175 km, has been established by Kudeki and Fawcett (September, 1993). They based their claims by comparing vertical drift measurements at these altitudes with simultaneous ground magnetogram records made in Ancon, which showed a high non linear correlation between the two. In this paper we present more direct correspondence by comparing simultaneous measurements made at F-region heights, using the standard I.S. technique with measurements made using the coherent echoes at the 135-175 km altitude. The correspondence is one to one. In addition, it is shown that there is also correspondence between the E-W drifts (vertical component of the electric field) measured at these two altitude ranges. Furthermore, it is shown that samples taken, for the last 3 years, at the 190 km nominal altitude, with the usual Jicamarca F-region drift mode, are strongly "contaminated" by the filtered tail from the stronger lower altitude coherent echoes and carry the same vertical drift information. The correspondence again is one to one, with the added advantage that their error bars are much smaller. This "contaminated" data was excluded in the past from the usual analysis. We are now recovering it to produce cleaner vertical and E-'N drifts drift series during the day. The new data presents special advantages in studding the effects of magnetic storms at a highcr resolution. Previously, one minute resolution data was too noisy to detect small and fast electric field perturbations.
    Palabras clave:Electric fieldsIonosphereEchoes
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    Desarrollo de un prototipo de conmutador TR de radar de 800 kW
    (Instituto Geofísico del Perú, 2010) Villanueva, Fernando; Castillo, Otto
    Diapositivas presentadas en el XIII Encuentro Científico Internacional, (ECI 2010i), realizado del 2 al 6 de agosto de 2010 en la ciudad de Lima, Perú.
    Palabras clave:RadarTecnología electrónicaIngeniería eléctrica
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    Observaciones de las inestabilidades KH en la tropósfera, usando un radar de alta resolución
    (Instituto Geofísico del Perú, 2010) Villanueva, Fernando; Woodman Pollitt, Ronald Francisco; Castillo, Otto
    El Radio Observatorio de Jicamarca (ROJ), cuenta con el radar SOUSY de alta resolución, el cual fue donado al Instituto Geofísico del Perú, por el Instituto Max Plank, de Alemania a mediados del 2001. La antena del radar, está constituida por un arreglo cuadrado de 65 m de lado, conformada por 256 antenas Yagi, ubicada cerca del cuarto Sur de la antena principal de Jicamarca (figura 1). Su ubicación permitirá realizar experimentos, que requieran, por ejemplo, una línea de base larga Norte-Sur, y que es usada particularmente para estudios de sensibilidad de aspecto de irregularidades en la ionosfera (figura 2). Los resultados que se presentan en el presente poster corresponden a observaciones de la tropósfera, y han sido obtenidos con la antena en posición vertical, utilizando en el transmisor la etapa previa driver, esto equivale a una potencia de 20 Kw, con codificación del pulso del transmisor de 64 baudios, y ancho de código de 250 ns (resolución de 18.75m). La figura 3 nos muestra la respuesta del sistema, transmisor-receptor.
    Palabras clave:AeronomíaTropósferaRadar