Assessment of the Ionospheric and Tropospheric Effects in Location Errors of Data Collection Platforms in Equatorial Region during High and Low Solar Activity Periods

The geographical locations of data collection platforms (DCP) in the Brazilian Environmental Data Collection System are obtained by processing Doppler shift measurements between satellites and DCP. When the signals travel from a DCP to a satellite crossing the terrestrial atmosphere, they are affected by the atmosphere layers, which generate a delay in the signal propagation, and cause errors in its final location coordinates computation. The signal propagation delay due to the atmospheric effects consists, essentially, of the ionospheric and tropospheric effects. This work provides an assessment of ionospheric effects using IRI and IONEX models and tropospheric delay compensation using climatic data provided by National Climatic Data Center. Two selected DCPs were used in this study in conjunction with SCD-2 satellite during high and low solar activity periods. Results show that the ionospheric effects on transmission delays are significant (about hundreds of meters) in equatorial region and should be considered to reduce DCP location errors, mainly in high solar activity periods, while in those due to tropospheric effects the zenith errors are about threemeters. Therefore it is shown that the platform location errors can be reduced when the ionospheric and tropospheric effects are properly considered

A realidade aumentada e virtual como métodos de ensino / Augmented and virtual reality as teaching methods

O presente documento discorre sobre a evolução do aprendizado e como os métodos de ensino tem mudado para se adaptar a uma realidade digital. Também discute o uso da Realidade Aumentada (RA) e da Realidade Virtual (RV) como ferramentas facilitadoras do processo de ensino e aprendizagem em um cenário interdisciplinar e apresenta experiências recentes como os aplicativos FDT-VR e Mohr2DVR, utilizados no ensino em disciplinas de engenharia, e o projeto Conquistando o Espaço, que foi idealizado por membros da comunidade acadêmica da Universidade Federal do ABC (UFABC) e consiste em um software educacional baseado em realidades aumentada e virtual

Avaliação da influência da ionosfera no erro de localização de plataformas de coleta de dados nos períodos de alta e baixa atividade solar

The location of Data Collection Platforms (DCPs) is obtained by Doppler shift measurements, considering the Brazilian System of Environmental Data Collection. The ionosphere can be considered as an important error source to the platforms location, due to its dispersive environment characterized by ions and free electrons. The representation of ionosphere is made by the measurement of Total Electron Content (TEC). The ionospheric effects are related to the geographical location, the season, hour of the day, geomagnetic and solar activities, and others. This work analyzes two different ionospheric models that describe TEC values (IONEX and IRI), considering high and low solar activity periods and using Doppler shift measurement related to SCD-2 satellite. The first analyses show that, in high solar activity, one of the models (IONEX) describes better the TEC values than other. So, the platform location errors can be minimized when IONEX model represents the ionosphere. On the other hand, in low solar activity periods both models represent TEC values in a similar way. Results of the analyses show that the ionospheric effects on transmission delays are significant (between ten to hundred meters) and should be considered to reduce DCP location errors, mainly in high solar activity periods, using the IONEX model.Pages: 8946-895