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Item Open Access The rocket interferometer tracking (RIT) system(NASA, 1965) Spafford, Michael; Wiack, Richard; Woodman Pollitt, Ronald FranciscoA Rocket Interferometer Tracking (RIT) system is described. It uses a modified 108 Me Minitrack receiver converted for 73.6 Me operation and a newly developed phase measuring system. The output of the system is real time direction cosine data for two channels, East-West and North-South, in analog and digital form. The analog data are recorded on an x-y recorder and on a strip chart recorder; and the digital data are automatically recorded on punched tape. The RIT system has been integrated with the ranging portion of the Radio Doppler Interferometer Tracking system (RADINT) at the Wallops Island Launch facility, and records the range data on the same punched tape.Item Restricted On the control of the F-region drift velocity by the E-region electric field: experimental evidence(Elsevier, 1969) Balsley, Ben B.; Woodman Pollitt, Ronald FranciscoExperimental evidence is presented which shows a good correlation between velocity variations of 1. (1) the vertical motions of the F-region electrons in the equatorial ionosphere, and 2. (2) the horizontal motions of electrons in the underlying E-region. This observation supports the theory that the E-region electric fields are projected into the F-region along the electrically equipotential magnetic field lines.Item Restricted Methods for the measurement of vertical ionospheric motions near the magnetic equator by incoherent scattering(American Geophysical Union, 1969-03-01) Woodman Pollitt, Ronald Francisco; Hagfors, T.Methods are discussed for the measurement of motions of the ionosphere by means of Doppler shifts of incoherent scatter frequency spectra. It is found that velocities can be measured with an accuracy of better than a few meters per second with integration times of a few minutes, provided the antenna beam us directed approximately perpendicular to the geomagnetic field.Item Open Access Investigación ¿Para qué?(Instituto Geofísico del Perú, 1970-03-19) Woodman Pollitt, Ronald FranciscoEl avance que ha experimentado la humanidad en los últimos decenios se debe pura y exclusivamente a la investigación. Los avances científicos y tecnológicos que tanto nos impresionan se deben el mayor y mejor conocimiento que tiene el hombre en todas las diferentes ciencias y sus tecnologías afines. De dónde proceden todos estos nuevos conocimientos? Todos, exclusivamente todos, son frutos de la investigación. No existe ningún otro procedimiento para incrementar el conocimiento de la humanidad que no sea la investigación. Esto lo podríamos tomar aún como la definición misma de la investigación: investigación es toda aquella actividad del hombre destinada a incrementar los conocimientos de la humanidad.Item Restricted Inclination of the geomagnetic field measured by an incoherent scatter technique(American Geophysical Union, 1971-01-01) Woodman Pollitt, Ronald FranciscoA technique to measure the direction of the geomagnetic field by using incoherent scatter techniques is described. The technique has been used to measure the inclination of the magnetic field at the Jicamarca Radar Observatory with an accuracy of the order of 1 minute of arc in the height range from 200 to 800 km. The corresponding inclinations obtained from the Goddard Space Flight Center (12/66) and the International Geomagnetic Reference Field (10/68) models are found to be about 1° in error.Item Open Access Simultaneous measurements of the electric field in the auroral zone and at the equator during intense magnetic activity(Max-Plank Institute für Aeronomie, 1972) Kelley, M.C.; Gonzáles, C.; Mozer, F.S.; Woodman Pollitt, Ronald FranciscoSimultaneous balloon measurements of the auroral zone electric field in Alaska and of the vertical drift velocity of the region at Jicamarca, Peru during the great flow of August 1972 are presented.· The eastward electric field component at the equator was correlated, with a 20 minute time delay, to the westward component of the auroral zone field at College, Alaska. The equatorial horizontal component actually reversed in sign from the normal westward value and, simultaneously, the electrojet then flowing over the dayside hemisphere (at Trivandrum, India, fer example) was greatly depressed. These results show that intense auroral current systems can grossly affect both the normal dynamo current patterns at low latitudes en the dayside and the polarization fields responsible fer the worldwide low latitude zonal electric field component.Item Restricted East-west ionospheric drifts at the magnetic equator(Instituto Geofísico del Perú, 1972-01-01) Woodman Pollitt, Ronald FranciscoA technique has been developed to measure the electromagnetic east-west drift velocity of the F region ionosphere by means of the Jicamarca incoherent scatter radar. Results show a fairly consistent behavior from day to day even during a magnetically disturbed day. Velocities are westward with a maximum of the order of 50 m/sec during the day, and eastward with a maximum of the order of 135 m/sec during the night. They are shown as experimental evidence for the superrotation of the neutral atmosphere at equatorial latitudes, but with a velocity smaller than the values inferred from satellite drag.Item Restricted Synthesis of data obtained at Jicamarca, Peru, during the September 11, 1969, eclipse(American Geophysical Union, 1972-02) Sterling, D. L.; Hanson, W. B.; Woodman Pollitt, Ronald FranciscoContinuous measurements of electron temperatures, electron concentrations, and vertical plasma drift were made at Jicamarca during the September 11, 1969, solar eclipse. Control measurements were made on September 13, 1969. Synthesis of the observed electron concentrations was made, using a model that solved the time‐dependent electron‐ion continuity equations. Ions O+, NO+, O2+, and N2+ were treated. Physical and chemical processes pertinent to the F region were considered in a realistic way. At noon, 300 km above Jicamarca, we obtained the values q = 290−3 sec−1 for the O+ production rate, β = 1.94 × 10−4 sec−1 for the loss coefficient, and H = 59 km for the atomic oxygen scale height. All large‐scale features observed in the F2 region were synthesized by the model. This synthesis was not sensitive to a simultaneous 30% reduction of q and β.Item Restricted Synthesis of Jicamarca Data During the Great Storm of March 8, 1970(American Geophysical Union, 1972-07) Woodman Pollitt, Ronald Francisco; Sterling, D. L.; Hanson, W. B.Continuous measurements of electron temperature and electron concentration were made at Jicamarca from 0700 to 0830 LT and from 1130 to 2000 LT during the great magnetic storm of March 8, 1970, when the F2 peak rose as high as 800 km. Continuous measurements of the vertical component of E×B drift were made from 1130 to 1730 LT. A synthesis of the observed electron concentrations was made using a model that solved the time‐dependent electron‐ion continuity equation for O+ and the molecular ions; the latter chemistry was included to improve the solutions at lower heights. It was found, using the observed values of vertical drift, that most of the observed features of the F2‐region ionosphere were synthesized by the model. An interpretation of the synthesis that emphasizes the importance of horizontal diffusion at the equator is given. Observations are presented for March 7, 8, and 9, 1970, including the Huancayo magnetograms, which display a close correlation with the drift measurements.Item Restricted Radar observations of equatorial spread F in a region of electrostatic turbulence(American Geophysical Union, 1972-10-01) McClure, J. P.; Woodman Pollitt, Ronald FranciscoRadar observations of a welldeveloped layer of strong equatorial spread F are presented. The scattering cross section, correlation lifetime, and vertical electromagnetic drift velocity of the spread-F irregularities were measured as a function of altitude and time with resolutions of 10 km and I min, respectively. The vertical drift velocities were often 100 m/sec, which is greater by a factor of 3 to 4 times than the vertical drift velocity of the normal undisturbed equatorial ionosphere at similar times. Also the velocity pattern exhibited a turbulent structure, changing sign irregularly every few tens of km and every few minutes, on the average. This observation confirms a recent satellite implication that, based on similarities in their statistical occurrence patterns, electrostatic turbulence and spread F are related. Finally, the finding that the correlation lifetimes of the 3-meter irregularities responsible for radar backscatter vary inversely with the scattering cross section confirms and extends earlier radar results.Item Restricted Source and identification of heavy ions in the equatorial F layer(American Geophysical Union, 1972-10-01) Hanson, W. B.; Sterling, D. L.; Woodman Pollitt, Ronald FranciscoFurther evidence is presented to show that the interpretation of some Ogo 6 retarding potential analyzer (RPA) results in terms of ambient Fe+ ions is correct. The Fe+ ions are observed only within dip latitudes of ±30°, and the reason for this latitudinal specificity is discussed in terms of a low‐altitude source region and F region diffusion and electrodynamic drift. It is shown that the polarization field associated with the equatorial electrojet will raise ions to 160 km out of a chemical source region below 100 km but it will do so only in a narrow region centered on the dip equator. Subsequent vertical E × B drift, coupled with motions along the magnetic fields, can move the ions to greater heights and greater latitudes. There should be a resultant fountain of metallic ions rising near the equator that subsequently descends back to the E and D layers at tropical latitudes. Even if the metallic ions do have access to the lower F region at higher latitudes, the downward plasma flow at the F peak will restrict their access to the upper F region.Item Open Access Simulación digital-analógica por computadora de comunicaciones vía electrochorro ecuatorial(Editor no identificado, 1973) Valladares, César; Woodman Pollitt, Ronald FranciscoEste trabajo muestra una técnica de simulación en un computador de comunicaciones vía electrochorro ecuatorial para determinar la calidad de cada sistema de comunicaciones e implementar el sistema óptimo, como la calidad de un sistema de comunicación, está determinado por su inmunidad contra el ruido y siendo el electrochorro ecuatorial parte del sistema pero tal que no puede ser afectado o mejorado se trabaja sobre la otra parte del sistema ensayando tipos de transmisiones y técnicas no convencionales de recepción con el fin de obtener un conjunto que afecte al mínimo las señales.Item Open Access Comparison of Te and Ti from Ogo 6 and from various incoherent scatter radars(American Geophysical Union, 1973-01-01) McClure, J. P.; Hanson, W. B.; Nagy, A. F.; Cicerone, R. J.; Brace, L. H.; Baron, M.; Bauer, P.; Carlson, H. C.; Evans, J. V.; Taylor, G. N.; Woodman Pollitt, Ronald FranciscoLangmuir probe and retarding potential analyzer (RPA) data on the electron and ion temperatures Te and Ti obtained from Ogo 6 are compared with Te and Ti values obtained from the incoherent scatter network. The satellite to radar temperature ratio TeS/TeR is 1.15 on the average for these comparisons. This discrepancy is larger than the uncertainties usually placed on the probe and radar Te values. It is, however, a smaller discrepancy than that found in many previous comparisons of this type. Our data do not appear to give any insight into the cause of the discrepancy. The ion temperature ratio TiS/TiR is approximately 1.0, independent of the particular radar examined. The internal accuracy of the RPA Ti data set was ±5% or better. Thus this comparison serves as an intercalibration of the incoherent scatter network. Since no significant systematic errors (i.e., errors larger than the statistical errors) exist between the RPA and radar Ti data, it appears very unlikely that any significant systematic errors exist in either data set. It should be noted, however, that the comparison data were limited to mainly nighttime hours and thus to relatively low temperatures and were heavily weighted to altitudes between 400 and 600 km, where suspected sources of systematic error are minimum.Item Open Access Correlation between ionospheric drift motions measured at low dip latitudes by the ion-cloud technique and at the equator by incoherent scatter(University of Texas at Dallas, 1973-05) Valenzuela, A.; Kappler, H.; Haerendel, G.; Föppl, H.; Hippman, H.; Woodman Pollitt, Ronald FranciscoThe Max-Planck-Institut für extraterrestrische Physik, Munich, Germany, and the National Commission on Space Research from Argentina conducted cooperative experiment involving the release of barium and europium clouds at altitudes between 140 and 250 kn. Three rockets were launched from. Chamical, Argentina (14.9° Dip Lat) in November 1972. Electric fields of the order of 2.0 mV/m were deduced from the ion cloud drifts during evening twilight and 0.5 mV/m during morning twilight. If projected along field lines to the magnetic equatorial plane the drift velocities can be compared with velocities measured simultaneously with the incoherent scatter radar at Jicamarca and with earlier measurements at the magnetic equator. This comparison suggests that the times of reversal of the vertical and horizontal velocities during evening and morning hours depend on altitude in the sense that the reversals occur earlier at greater heights.Item Restricted Evidencia arqueológica del levantamiento continental al norte del Perú en los últimos 4 mil años(Sociedad Geográfica de Lima, 1974) Woodman Pollitt, Ronald Francisco; Polla, MarioQuien ha tenido la oportunidad de visitar el balneario de Colán (Piura, Perú, Long. 81°05' Oeste, Lat 5°01' Sur) es muy probable que se haya extrañado al notar la distancia a la que se encuentra el pueblo de pescadores de la playa desde la cual inician sus labores de pesca. Si bien las casas de veraneo, construidas relativamente en fecha reciente (hace unos cuarenta años), se encuentran a la orilla del mar, el pueblo de pescadores de Colán, que da el nombre de balneario, se encuentra cerca de un kilómetro y medio de la playa. Diariamente a los pescadores se les ve hacer este largo recorrido acarreando sus instrumentos de pesca al atardecer, y al día siguiente, los frutos de sus trabajo, al amanecer. Basta notar el nivel relativamente bajo de la explanada salitrosa que separa al pueblo del mar, para llegara a la conclusión que el mar les debe haber hecho una mala jugada. El pueblo debe de haber nacido cuando las orillas del mar se encontraban al borde de éste, luego el mar se debe haber retirado, en laguna forma, a donde se encuentra actualmente. Para explicar la retirada del mar caben dos alternativas: o el mar, en un proceso de sedimentación, ha creado las tierras ahora secas que lo separan del pueblo, o ha "bajado de nivel" con relación al pueblo, alejándose en el proceso a una distancia correspondiente a la pendiente de lo que originalmente fue el fondo marino de sus orillas.Item Open Access Radar observations of the development of tropical thunderstorms and convection cells using the Arecibo radar(Instituto Geofísico del Perú, Radio Observatorio de Jicamarca, 1974) Larsen, M.F.; Swartz, W.E.; Woodman Pollitt, Ronald FranciscoIn the period from 13 Sept to 20 Sept 1979, the 430 MHz radar system at the Arecibo Observatory was used to study profiles of vertical velocity in developing and mature thunderstorms during the afternoon hours. During the eight day period, five days produced significant convective activity. The great sensitivity of the Arecibo radar facility allowed vertical velocities to be measured up to an altitude of 20 km. Since the tropopause over Puerto Rico is at an altitude of approximately 14 km at that time of year, the lower part of the stratosphere was also observed during the period of cloud development. Many studies have been carried out using Doppler radars to probe the interior of convective cells (see Wilson and Miller, 1972 for an excellent review and bibliography; also Battan, 1973). This is particularly true of radars operating at shorter wavelengths of 3 or 10 cm whích are more sensitive to reflections from precipitation within the clouds. The Arecibo radar, operating ata wavelength of 70 cm, receives echoes from variations in the index of refraction with a scale size of half the wavelength, or 35 cm. The fact that vertical velocities could be measured in both the troposphere and lower stratosphere is of particular interest.in view of the theory that the upward flux of mass in the tropical branch of the Hadley cell is concentrated in the cumulus towers (Riehl and Malkus, 1958; Reiter, 1975). Puerto Rico, at approximately 13°N latitude, is in this branch of the Hadley cell.Item Open Access Radar measurements of gravity waves in the ionosphere(Akademie-Verlag, 1974) Woodman Pollitt, Ronald FranciscoSome characteristic parameters of gravity waves at D and E region heights such as amplitude, frequency spectrum and spatial properties can and have been measured by means of VHF radars. One of the techniques makes use of ionization trails produced by meteors as tracers of the neutral atmosphere motions in the region from 80 to 100 km. A recently developed technique at the Jicamarca Radio Observatory uses background enhanced fluctuations in the dielectric properties of the medium as tracers of the neutral motions in the region between 60 and 85 km. Profiles of the velocity field can be obtained continuously with a time resolution of the order of a minute allowing observations of gravity waves from its lowest periods, of the order of a few minutes, to tidal periods. Gravity waves in the lower F region have also been detected using incoherent scatter techniques. The methods, potential and limitations of the above mentioned techniques are reviewed as well as some of the results obtained.Item Open Access Beobachthung der Brillouin-Instabilität in der Ionosphäre(Editor no identificado, 1974) Fejer, J.A.; Rinnert, K.; Woodman Pollitt, Ronald FranciscoObservations of weak stimulated Brillouin scattering with the 50 MHz incoherente scatter radar at Jicamarca are described. The non-linear interaction uf the upgoing radar wave with the downcoming waves, incoherently backscattered fromm greater heights, causes an asymmetry in the incoherent "ion" backscatter spectrum. For a given antenna aperture this asymmetry increases with increasing power and decreasing frequency of the rdar. The theoretically predicted effect was unambiguuosly verified, using 3 msec pulses and long integration time. Model calculations show good agreement with the observations.Item Open Access Radar observations of winds and turbulence in the stratosphere and mesosphere(American Meteorological Society, 1974-03) Woodman Pollitt, Ronald Francisco; Guillén, AlbertoA technique for the observation of radar echoes from stratospheric and mesospheric heights has been developed at the Jicamarca Radio Observatory. Signals are detected at the altitude ranges between 10–35 km and from 55–85 km with powers from many to several tens of decibels above noise level. The three most important frequency spectrum characteristics-power, Doppler shift and spectrum width-are observed in real time. The power levels as well as the spectral width are explained in terms of turbulent layers, with a thickness of the order of 100 m, in regions with a positive potential temperature or electron density vertical gradients. Continuous wind velocity records are obtained with a precision of the order of 0.02–0.2 m sec−1 for the vertical component and 0.20–2 m sec−1 for the horizontal, with a time resolution of the order of 1 min. The highest precisions are obtained at stratosphere heights. Fluctuations in velocity in the mesosphere are observed at the shortest gravity wave periods with amplitudes of the order of 1 m sec−1 for the vertical component and of 10 m sec−1 for the horizontal. Tidal components at these altitudes are not as large as predicted by theory. A technique to obtain the power, the Doppler shift, and the width of the frequency spectrum of the echo signals from only two points of the correlation function is described.Item Restricted Mesospheric studies using the Jicamarca incoherent-scatter radar(Elsevier, 1974-07) Rastogi, P. K.; Woodman Pollitt, Ronald FranciscoResults from a VHF backscattering experiment using the Jicamarca incoherent-scatter radar are described for a mesospheric height. The echo power during the day varies intermittently and sporadically over a range of almost 30 dB with a median strength about 4 dB above the incoherent-scatter level. The enhanced echo power is generally associated with a wider autocorrelation function. The autocorrelation function often exhibits a second peak. Vertical and zonal or meridional velocities have been obtained from the complex autocorrelation function using two closely pointed antennas. Long sequences of these velocity measurements have been shown to correspond to internal gravity waves.