Presentation at the 2021 CEDAR Virtual Workshop, June 20-25.

Diapositivas presentadas en 2008 Annual Summer CEDAR Workshop, 16-21 June 2008. Midway, Utah, USA.

Diapositivas presentadas en el XIII Encuentro Científico Internacional, (ECI 2010v), realizado del 5 al 8 de enero de 2010 en la ciudad de Lima, Perú.

Diapositivas presentadas en The Meeting of the Americas (AGU), llevado a acabo del 8 al 12 de agosto 2010 en la ciudad de Foz do Iguassu, Brasil.

Diapositivas presentadas en el II Encuentro Nacional de Radio Científicos e Investigadores Afines 2010 (URSI- PERÚ), llevado a cabo en la Pontificia Universidad Católica del Perú.

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.

Diapositivas presentadas en el Encuentro Científico Internacional, ECI-2010, celebrado en Lima, Perú.

In this dissertation, Coulomb collisions and magnetoionic propagation effects on the incoherent scatter radar measurements have been studied and analyzed in detail. The present study aims at modeling radar observations of the equatorial ionosphere carried out at the Jicamarca Radio Observatory (Lima, Peru) using antenna beams pointed perpendicular to the Earth’s magnetic field B.

Presentation at the 2020 CEDAR Virtual Meeting, June 22-26.

The ALTAIR UHF radar was used in an incoherent scatter experiment to observe the low-latitude ionosphere during the Equis 2 rocket campaign. The measurements provided the first high-resolution electron density maps of the low-latitude D- and E-region in the Pacific sector and also extended into the F-region and topside ionosphere. Although the sampling frequency was well below the Nyquist frequency of F-region returns, we were able to estimate Te/Ti ratio and infer unbiased electron density estimates using a regularized inversion technique described here. The technique exploits magnetic aspect angle dependence of ISR cross-section for Te>Ti.

A multi-beam incoherent scatter radar technique has been developed at the Jicamarca Radio Observatory in order to maximize the number of ionospheric parameters that can be estimated simultaneously. The technique interleaves radar observations with antenna beams pointing perpendicular and oblique to the Earth's magnetic field. For the estimation of the ionospheric parameters, we have modeled the magnetic aspect angle variations of the signal power and cross-correlation data measured in multiple directions. The data model, formulated in terms of soft-target radar equations, was built based on the theories of incoherent scattering and magneto-ionic propagation. Applying a nonlinear least-squares inversion algorithm, we have succeeded in measuring simultaneously ionospheric electron densities Ne, electronto-ion temperature ratios Te=Ti as well as vertical and zonal plasma drifts. In the past...

The main concern of this thesis is the estimation of ionospheric parameters from incoherent scatter (IS) power data collected with the ALTAIR radar. The estimation is performed using a radar calibration and inversion technique based on a forward model of the scattered power. The model considers the physics of the ionosphere in terms of IS radar cross section (RCS) of the medium. The inversion procedure provides the estimates of plasma density and electron-ion temperature ratio (Te/Ti) of the probed ionosphere.

Diapositivas presentadas en: ISEA 12 - 12th International Symposium on Equatorial Aeronomy, May 18-24, 2008. Crete, Greece.

El informe de investigación se enfoca en uno de los principales retos de una empresa de gestión de cobranzas el cual consiste en entender cómo mejorar la generación de compromisos de pago en las llamadas telefónicas a clientes deudores. Para esto se usan modelos predictivos aplicados a variables del entorno de la negociación en la llamada y variables de la segmentación, que luego se comparan sus desempeños predictivos. La realización de este objetivo se desarrolla bajo la metodología CRISP-DM para la estructuración del proyecto, así mismo se propuso un plan de trabajo para cumplir en 15 semanas el desarrollo del modelo de mejor desempeño. La empresa objeto de estudio es RECSA, una compañía con más de 30 años de experiencia en gestión de cobranza en América Latina. El trabajo investiga cómo mejorar la efectividad de las llamadas de cobranza y generar compromisos de pag...

La tesis tuvo como objetivo determinar de qué manera se relaciona el aprendizaje cooperativo y las actitudes hacia el Cálculo I. El enfoque de la investigación fue cuantitativo de tipo aplicado. El diseño fue no experimental, transversal, descriptivo y correlacional. La población estuvo conformada por 85 estudiantes. La técnica utilizada fue la encuesta y el instrumento un cuestionario con escala tipo Likert. La validez por Juicio de expertos resultó de 96,5% para el cuestionario de aprendizaje cooperativo y 96,6% para el cuestiorario de Actitudes hacia el cálculo I, por lo que el instrumento tiene validez excelente. La confiabilidad con Alfa de Cronbach resultó 0,95 (aprendizaje cooperativo) y 0,978 (actitudes hacia el Cálculo I). Los resultados indican que el 81,2% de los encuestados afirman que la relación entre el aprendizaje cooperativo y las actitudes hacia el Cálculo I...

Contenido de la charla: 1. Planteamiento del Problema -Modos de Dispersion Incoherente 2. Non Linear Least-Square -Algoritmo de Levenberg-Marquardt 3. JRO Cluster -Software - Hardware 4. Implementacion del Algoritmo - Método de Trabajo 5. Resultados.

A novel technique for radar-imaging inversions is proposed which leverages ideas from the emerging field of compressed sensing. This new method takes advantage of the transform sparsity inherent in natural images. Theoretical recovery results are promising and are borne out by simulations in which this technique outperforms Capon’s method and the Maximum Entropy method. Preliminary results using data collected at the Jicamarca Radio Observatory are also presented.

A small network of HF beacon transmitters and receivers has been deployed in Peru for specifying the F region ionosphere in the sector. The effort is motivated by ionospheric disturbances associated with equatorial spread F (ESF) and specifically disturbances arising under inauspicious conditions for ESF as determined by numerical simulations. The beacons operate at dual frequencies (2.72 and 3.64 MHz). They are CW but incorporate pseudorandom noise (PRN) coding so that the group delays of the links can be measured. Other observables are power, Doppler shift, bearing, and polarization. A transmitter is currently deployed at Ancon (11∘46’37’’S, 77∘09’1’’W, 51 m above sea level (asl)), while receivers are at Jicamarca (11∘57’5.8’’S, 76∘52’27’’W, 510 m asl) and Huancayo (12∘02’30’’S, 75∘19’15’’W, 3315 m asl). An algorithm for inverting the bea...

Poster presented at the 2021 CEDAR Virtual Workshop, June 20-25.

Previous studies of the Earth's low‐latitude ionosphere using in situ measurements made by sensors on the Communication/Navigation Outage Forecasting System (C/NOFS) satellite showed an unexpected predominance of equatorial spread F (ESF) events in the postmidnight sector during June and December solstice months of the 2008–2009 deep solar minimum. It has been suggested that these events might have been driven by the unusual behavior of the equatorial plasma drifts, which showed an abnormal upward peak around midnight during the same period. We use coherent backscatter radar (Jicamarca Unattended Long‐term Investigations of the Ionosphere and Atmosphere ‐ JULIA) measurements made at the Jicamarca Radio Observatory (11.95°S, 76.87°W, ∼1∘ dip lat) in Peru to better understand the origin of the ESF irregularities observed by C/NOFS. The radar observations show that ESF events ...