Browsing by Author "Pacheco, Edgardo E."
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Item Restricted Automatic identification and observations of blanketing sporadic E events in the equatorial region over Jicamarca(Institute of Electrical and Electronics Engineers, IEEE, 2020-10-20) Suclupe, José; Pacheco, Edgardo E.; Condor, PercyIn equatorial regions, equatorial electrojet (EEJ) echoes often overlap with blanketing sporadic E (Esb) echoes. Also, Esb events could be classified as rare events over the Jicamarca Radio Observatory (JRO). For that reason, Esb identification is a big challenge for current software. Until now, the conventional method identifies Esb echoes visually. In this work, an innovative approach for automatic identification and observation of Esb events is presented. We developed an algorithm and implemented the first software to identify Esb events using image processing techniques and machine learning algorithms getting a sensitivity of 89%. We proposed a new criterion to identify Esb events taken into account the normal tendency of the F-layer minimum frequency due mainly to absorbance of the D region. We report the results of the first statistical study of Esb occurrence over JRO (11.95° S, 76.87° W and dip angle ~1°) using the Digital Portable Sounder (DPS) - 4 Digisonde data from 2001 to 2018. We found Esb occurs mainly during the December solstice and also during minimum solar years. We observe the occurrence of Esb with a main peak at 1600 LT and a second peak around 0800 - 0900 LT. Furthermore, we obtained the ΔH between Jicamarca and Piura to measure the intensity of EEJ and counter electrojet (CEJ) and its behavior in time when Esb occurs. Finally, we discuss possible conditions that favor the formation of Esb.Item Restricted Design of a Programmable Radar Controller ASIC on VHDL for a Modular Radar System(IEEE, Institute of Electrical and Electronics Engineers, 2021) Verastegui, Joaquin; Manay, Ivan; Pacheco, Edgardo E.; Milla, MarcoThe Jicamarca Radio Observatory (JRO), funded by the USA National Science Foundation (NSF), operates several radars for different applications, from the main radar, an incoherent scatter radar used mainly for ionospheric activity observations, to ionosondes and wind profilers. Most of these radars use a centralized modular control system that commands all the radar sequences that require the radar modules, these tasks and sequences are controlled by pulsed digital signals. The device responsible for this operation is called the Radar Controller. A large number of customized Radar Controller versions were developed and built at JRO for decades, since the utilization of its first acquisition system. The current version of the Radar Controller is based on an RTL design written on VHDL language that implements a custom arbitrary waveform generator connected to an SRAM memory that stores all the data a given waveform needs. The Radar Controller uses a register based architecture to communicate between blocks internally. In JRO we use a Spartan 6 FPGA and it is controlled by a Tiva C microcontroller board which has an Ethernet port. A Restful API has been implemented on the microcontroller for user configuration. This paper will cover the VHDL RTL design of the current version of the Radar Controller core.Item Open Access Diseño e implementación de un sistema receptor para la estimación del contenido total de electrones relativo (rTEC)(Universidad Peruana de Ciencias Aplicadas, 2017) Gómez Sócola, Josemaría; Salas Arriarán, Sergio; Pacheco, Edgardo E.En el Radio Observatorio de Jicamarca (ROJ) se ha desarrollado un sistema receptor digital de señales de radiofrecuencia provenientes de satélites de baja órbita. Este receptor terrestre calcula la variación del Contenido Total de Electrones (rTEC, del inglés relative Total Electron Content) en la ionosfera que tal y como su nombre lo diceel rTEC está relacionado al contenido total de electrones o densidad de iones en la ionosfera. Este sistema tiene la capacidad de obtener señales transmitidas desde nano satélites y satélites en general que cuenten con un payload específico. En un futuro el sistema receptor será capaz de captar las señales del transmisor del nanosatélite desarrollado por el ROJ. Las mediciones del rTEC obtenidas permitirán investigar la ionósfera ecuatorial y observar eventos y fenómenos de interés cuando se presenten irregularidades. En el presente trabajo de tesis, se hará una descripción del sistema y se explicará cómo el sistema receptor determina el rTEC usando la técnica llamada Differential Doppler. Asimismo se mostrarán los resultados de detección del rTEC utilizando las señales de radio frecuencias transmitidas por satélites que se encuentran operativos como COSMOS, CASSIOPE y DMSP-F15. Finalmente se mostraran las comparaciones de estos resultados con mediciones obtenidas por otro receptor del tipo analógico, las cuales presentan un alto índice de correlación.Item Open Access Estudio de las capas E esporádicas tipo Blanketing sobre el Radio Observatorio de Jicamarca(Universidad Nacional de Ingeniería, 2019) Suclupe Osorio, José Manuel; Pacheco, Edgardo E.En esta tesis se ha desarrollado el primer estudio estadístico de la ocurrencia de las capas Esb sobre el Radio Observatorio de Jicamarca usando ionogramas de la Digital Portable Sounder (DPS) – 4 registrados entre 2001 y 2018. Se ha encontrado que estas capas Esb ocurren principalmente en los meses del solsticio de Diciembre sobre todo en años de mínima actividad solar. Además presentan mayor ocurrencia en años de mínima actividad solar respecto a años de máxima actividad solar. Estas capas ocurren principalmente entre las 0700 y las 2000 horas LT con un pico principal alrededor de las 1600 LT y un segundo pico alrededor de las 0800-0900 LT. Se ha propuesto un nuevo criterio para identificar las capas Esb teniendo en cuenta la tendencia normal de la frecuencia mínima de la capa F de la ionósfera debido principalmente a la absorción de la región D (región entre 50 y 80 km de altura). Además se ha realizado comparaciones de eventos Esb registrados por la digisonda DPS-4 y por la ionosonda VIPIR. Adicionalmente se ha obtenido el ΔH entre los magnetómetros de Jicamarca y Piura para medir la intensidad del electrochorro ecuatorial y contra electrochorro ecuatorial y su comportamiento en los tiempos donde ocurren capas Esb. Finalmente discutimos las posibles condiciones que favorecen la formación de las capas Esb.Item Open Access Exploration of machine learning tools developed for the study of space weather and its impact on position approximation in GNSS systems(Instituto Geofísico del Perú, 2021-06) Fajardo, G.; Pacheco, Edgardo E.The equatorial ionosphere has been extensively studied using purely physical models, however in recent years, with a large amount of data, it has been possible to improve these models using machine learning techniques. In this paper, we share the research results aimed to evaluate the influence of space weather parameters on GPS position approximation. We evaluated data from the Huancayo GPS station between 2016 and 2020 and we have taken into account the space weather data from the OMNI website, scintillation index (S4) and position data obtained from the GPS of the LISN network to perform our model. In addition, we use tropospheric conditions provided by the Geophysical Institute of Peru (IGP). The final result is a reliability matrix obtained with an XG Boost algorithm that will allow us to evaluate if a GPS signal given the conditions is indeed reliable or not.Item Open Access Exploring the correlation between ionospheric scintillation and GNSS positioning error near the magnetic equator using machine learning techniques(Instituto Geofísico del Perú, 2020-06) Fajardo, G.; Pacheco, Edgardo E.Ionospheric scintillations are a common phenomenon in the equatorial ionosphere. This phenomenon directly affects the position estimated by GNSS receivers degrading the quality of the radio signals; however, the quantification of the positioning error contributed by the ionosphere over the Peruvian sector has not been studied in detail. In this work, algorithms are being implemented that will allow us to identify and classify amplitude scintillation (S4) levels, we have worked with data from the Huancayo Observatory for the period December 2016-February 2017 obtained from LISN, this data has been plotted to analyze the spatial and temporal occurrence, and to analyze the occurrence of S4 as a function of other space weather variables obtained from OMNI2. The machine learning algorithms were decision tree, Support Vector Machine (SVM), Neuronal Network (NN). Decision tree was implemented as a filtering method, support vector machine for clustering and neuronal network to generate time series in forecasting. This paper shows the initial part of an investigation that aims to correlate qualitatively and quantitatively the occurrence of amplitude scintillations (S4) with errors in the position estimation of GNSS receivers, once the correlation between S4 and position error has been quantified, it may be possible to predict the error by predicting S4.Item Open Access Latitudinal (Apex - Height) variations of ion drifts in the ionosphere at low - and mid- latitudes(The University of Texas at Dallas, 2009) Pacheco, Edgardo E.; Heelis, RodEn este estudio nos centramos en la dinámica de las velocidades de deriva de iones en las latitudes bajas y medias. Se describe cómo estas derivas de iones varían en amplitud para diferentes longitudes, las estaciones y las horas locales específicos durante momentos de tranquilidad. Durante momentos de tranquilidad se utilizan los datos del satélite el ROCSAT-1 para describir la dependencia de latitud tres características principales de las derivas de iones meridional; las derivas a gran escala hacia arriba durante el día, una denominada mejora prereversal cerca de la oscuridad, y una mejora de la salida del sol hacia abajo. La longitud, latitud y dependencias de temporada en estas características se ven influenciadas por la alineación de los terminadores y el meridiano magnético, las conductividades tubo de flujo integrados y la acción de las mareas diurnas y semidiurnas en la ionosfera inferior. También se obtuvo una descripción de las derivas de iones zonales durante momentos de tranquilidad. Estas derivas muestran latitud, longitud y variaciones estacionales, impulsado por los efectos combinados de la región E y vientos Fregion. Los cambios en el viento y la región F Pedersen conductancia son responsables de latitud, longitud y los cambios estacionales en la súper-rotación neta de la ionosfera. Además, se describen las perturbaciones en tiempo de tormenta en las derivas de iones en el ecuador magnético. Estas perturbaciones se producen principalmente por undershielding y overshielding del campo eléctrico magnetosférica en momentos en que el campo magnético interplanetario está cambiando. El papel de la dinamo perturbación también se puede ver en las derivas de perturbación en el Ecuador. El uso de mediciones de la DMSP-F13, F-15 y el ROCSAT satélites-1 que son capaces de describir por primera vez, las perturbaciones deriva del tiempo de tormenta en el ecuador observar simultáneamente en diferentes momentos locales.Item Restricted New opportunities offered by Cubesats for space research in Latin America: The SUCHAI project case(Elsevier, 2016-11) Diaz, M. A.; Zagal, J. C.; Falcon, C.; Stepanova, M.; Valdivia, J. A.; Martinez-Ledesma, M.; Diaz-Peña, J.; Jaramillo, F. R.; Romanova, N.; Pacheco, Edgardo E.; Milla, Marco; Orchard, M.; Silva, J.; Mena, F. P.During the last decade, a very small-standardized satellite, the Cubesat, emerged as a low-cost fast-development tool for space and technology research. Although its genesis is related to education, the change in paradigm presented by this satellite platform has motivated several countries, institutions, and companies to invest in a variety of technologies, aimed at improving Cubesat capabilities, while lowering costs of space missions. Following that trend, Latin American institutions, mostly universities, has started to develop Cubesat missions. This article describes some of the Latin American projects in this area. In particular, we discuss the achievements and scientific grounds upon which the first Cubesat projects in Chile were based and the implications that those projects have had on pursuing satellite-based research in the country and in collaboration with other countries of the region.Item Restricted Observations of TIDs over South and Central America(American Geophysical Union, 2016-11-18) Valladares, Cesar E.; Sheehan, Robert; Pacheco, Edgardo E.TEC values measured by GPS receivers that belong to the low‐latitude ionosphere sensor network (LISN) and several other networks that operate in South and Central America were used to study the characteristics and origin of traveling ionospheric disturbances (TID) in these regions. The TEC perturbations associated with these TIDs show a high degree of spatial coherence over distances > 1000 km allowing us to use measurements from receivers spaced by hundreds of km to calculate the TIDs' travel velocities, propagation direction, and scale size. We first applied the TID analysis to TEC measurements corresponding to 4 July 2011. This processing method is then used to study the characteristics of TIDs for 20 and 21 August 2011, a period when a tropical storm was active in the Caribbean region. A pronounced increase in TID activity was observed in South and Central America at 16 UT on 20 August 2011 lasting until the end of 21 August 2011. The TID velocities show a very variable pattern that depends upon their local time and location. Counter‐streaming TIDs were observed over the western part of South America on 21 August 2011. Regional maps of tropospheric temperature brightness, measured by the GOES‐12 satellite, are used to identify and follow the development of the tropical storm (TS) Irene and several deep convective plumes. TIDs were observed propagating away from TS Irene. This storm moved into the Caribbean region and intensified earlier on 20 August spawning a train of atmospheric gravity waves (AGW). The small scale size, the velocity less than 150 m/s, and the close location of several TIDs with respect to TS Irene indicate that these TIDs may be the result of primary AGWs that reached the F‐region bottomside. These results open the possibility of using TEC values measured by networks of GPS receivers to construct regional, and probably global, maps of TIDs, identify their origin, and study in detail the characteristics of TIDs corresponding to primary and secondary AGWs.Item Restricted On the mutual relationship of the equatorial electrojet, TEC and scintillation in the Peruvian sector(American Geophysical Union, 2016-05-31) Khadka, Sovit M.; Valladares, Cesar; Pradipta, Rezy; Pacheco, Edgardo E.; Condor, PercyThis paper presents the interrelationship between the equatorial electrojet (EEJ) strength, Global Positioning System (GPS)‐derived total electron content (TEC), and postsunset scintillation from ground observations with the aim of finding reliable precursors of the occurrence of ionospheric irregularities. Mutual relationship studies provide a possible route to predict the occurrence of TEC fluctuation and scintillation in the ionosphere during the late afternoon and night respectively based on daytime measurement of the equatorial ionosphere. Data from ground based observations in the low latitudes of the west American longitude sector were examined during the 2008 solar minimum. We find a strong relationship exists between the noontime equatorial electrojet and GPS‐derived TEC distributions during the afternoon mediated by vertical E × B drift via the fountain effect, but there is little or no relationship with postsunset ionospheric scintillation.Item Open Access Statistical analysis of low latitude spread F at the American, Atlantic, and Pacific sectors using digisonde observations(Frontiers Media, 2024-07-30) Bhaneja, Preeti; Klenzing, Jeff; Pacheco, Edgardo E.; Earle, Gregory D.; Bullett, Terrence W.Statistical analysis of low latitude spread F is presented for three different longitudinal sectors from Jicamarca (12°S, 76.8°W, −2.5° declination angle) from 2001 to 2016, Ascension Island (7.9°S, 14.4°W, −15.09° declination angle) from 2000 to 2014, Kwajalein (8.71°N, 167.7°E, 7.5° declination angle) from 2004 to 2012. Digisonde data from these stations have been processed and analyzed to study statistical variations of equatorial spread F, a diagnostic of irregular plasma structure in the ionosphere. A new automated method of spread F detection using pattern recognition and edge detection for low latitude regions is used to determine solar and seasonal variation over these three sites. An algorithm has been developed to detect the foF2 and hpF2 parameters and this has been validated by comparisons with manually scaled data as well as with SAMI2 and International Reference Ionosphere models showing good correlation. While significant variation is not observed over the solar cycle, the different longitudes and declination angles contribute to the variations over the seasonal cycle.Item Open Access The impact of the Hunga Tonga–Hunga Ha’apai volcanic eruption on the Peruvian atmosphere: from the sea surface to the ionosphere(SpringerOpen, 2024-05-28) Pacheco, Edgardo E.; Velasquez, J. P.; Flores, R.; Condori, L.; Fajardo, G.; Kuyeng, Karim; Scipión, Danny; Milla, M.; Conte, J. F.; Poblet, F. L.; Chau, J. L.; Suclupe, J.; Rojas, R.; Manay, E.The eruption of the Hunga Tonga Hunga Ha’apai volcano on 15 January 2022 significantly impacted the lower and upper atmosphere globally. Using multi-instrument observations, we described disturbances from the sea surface to the ionosphere associated with atmospheric waves generated by the volcanic eruption. Perturbations were detected in atmospheric pressure, horizontal magnetic field, equatorial electrojet (EEJ), ionospheric plasma drifts, total electron content (TEC), mesospheric and lower thermospheric (MLT) neutral winds, and ionospheric virtual height measured at low magnetic latitudes in the western South American sector (mainly in Peru). The eastward Lamb wave propagation was observed at the Jicamarca Radio Observatory on the day of the eruption at 13:50 UT and on its way back from the antipodal point (westward) on the next day at 07:05 UT. Perturbations in the horizontal component of the magnetic field (indicative of EEJ variations) were detected between 12:00 and 22:00 UT. During the same period, GNSS-TEC measurements of traveling ionospheric disturbances (TIDs) coincided approximately with the arrival time of Lamb and tsunami waves. On the other hand, a large westward variation of MLT winds occurred near 18:00 UT over Peru. However, MLT perturbations due to possible westward waves from the antipode have not been identified. In addition, daytime vertical plasma drifts showed an unusual downward behavior between 12:00 and 16:00 UT, followed by an upward enhancement between 16:00 and 19:00 UT. Untypical daytime eastward zonal plasma drifts were observed when westward drifts were expected. Variations in the EEJ are highly correlated with perturbations in the vertical plasma drift exhibiting a counter-equatorial electrojet (CEEJ) between 12:00 and 16:00 UT. These observations of plasma drifts and EEJ are, so far, the only ground-based radar measurements of these parameters in the western South American region after the eruption. We attributed the ion drift and EEJ perturbations to large-scale thermospheric wind variations produced by the eruption, which altered the dynamo electric field in the Hall and Pedersen regions. These types of multiple and simultaneous observations can contribute to advancing our understanding of the ionospheric processes associated with natural hazard events and the interaction with lower atmospheric layers.