Análise de modelos troposféricos no posicionamento baseado em redes usando o conceito de VRS

In the past few years several GPS (Global Position System) positioning techniques have been develope and/or improved with the goal of obtaining high accuracy and productivity in real time. The reference station network concept besides to enabling quality and reliability in positioning for scientific and civil GPS community, allows studies concerning tropospheric refraction modeling in the network region. Moreover, among the network corrections transmission methods available to users, there is the VRS (Virtual Reference Station) concept. In this method, the data of a virtual station are generated near the rover receiver (user). This provides a short baseline and the user has the possibility of using a single frequency receiver to accomplish the relative positioning. In this paper, the methodology applied to generate VRS data, using different tropospheric models is described. Thus, comparative tests were conducted in the four seasons with the NWP/INPE (Numerical Weather Prediction/National Institute for Space Research) and Hopfield tropospheric models. In order to analyse the VRS data quality, it was used the Precise Point Positioning (PPP) method, where satisfactory results were found. Mean differences between PNT/INPE and Hopfield models of 9.75% and 24.2% for the hydrostatic and wet days, respectively were obtained.

Previsão da velocidade dos ventos por redes neurais artificiais e arima de box & jenkins

Pós-graduação em Engenharia Elétrica - FEIS

Diagnostics of equatorial and low latitude ionosphere by TEC mapping over Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alternative transfer to the Earth-Moon Lagrangian points L4 and L5 using lunar gravity assist

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

On the effects of each term of the geopotential perturbation along the time I: Quasi-circular orbits

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Zero, minimum and maximum relative radial acceleration for planar formation flight dynamics near triangular libration points in the Earth-Moon system

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Proposta de elaboração de um glossário bilíngue de termos simples, expressões fixas e semifixas da área de sensoriamento remoto

Brazil was one of the countries that stood out in the list of nations that publishes more articles in scientific journals. From 2007 to 2008, the Brazilian scientific production has moved from 15th to 13rd place in the world ranking published articles in professional journals. However, 60% of articles published by the Brazilians are in Portuguese, which makes the Brazilian work have little international attention. The purpose of this research is to build and analyze a parallel corpus composed of a book of Remote Sensing and its translation in the direction English into Portuguese in order to create a glossary of most recurrent terms in the literature of Remote Sensing. The achievement of these goals will take for theoretical and methodological foundation the Corpus-Based Translation Studies (BAKER, 1993, 1995, 1996; CAMARGO, 2005), Corpus Linguistics (BERBER SARDINHA, 2004) and principles of Terminology (BARROS, 2004; KRIEGER & FINATTO, 2004). It will also use Wordsmith Tools program and its tools. Besides the parallel corpus, we will also build two comparable corpora respectively from articles published in Brazilian and international journals in the area. The first results show that the translators made use of greater variation of vocabulary in their translations, which can be a way to make the text more clear to the reader. For the analysis of glossary entries, professionals from the National Institute for Space Research - INPE, will be consulted and their views aggregated to this research to give consistency to the production of the proposed bilingual glossary.

Avaliação das áreas de conflito de uso em APP na microbacia Ribeirão do Veado, Piratininga (SP) por meio de geotecnologias

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Validity and behaviour of tropospheric gradients estimated by GPS in Corsica

Estimation of tropospheric gradients in GNSS data processing is a well-known technique to improve positioning (e.g. Bar-Sever et al., 1998; Chen and Herring, 1997). More recently, several authors also focused on the estimation of such parameters for meteorological studies and demonstrated their potential benefits (e.g. Champollion et al., 2004). Today, they are routinely estimated by several global and regional GNSS analysis centres but they are still not yet used for operational meteorology.This paper discusses the physical meaning of tropospheric gradients estimated from GPS observations recorded in 2011 by 13 permanent stations located in Corsica Island (a French Island in the western part of Italy). Corsica Island is a particularly interesting location for such study as it presents a significant environmental contrast between the continent and the sea, as well as a steep topography.Therefore, we estimated Zenith Total Delay (ZTD) and tropospheric gradients using two software: GAMIT/GLOBK (GAMIT version 10.5) and GIPSY-OASIS II version 6.1. Our results are then compared to radiosonde observations and to the IGS final troposphere products. For all stations we found a good agreement between the ZWD estimated by the two software (the mean of the ZWD differences is 1 mm with a standard deviation of 6 mm) but the tropospheric gradients are in less good agreement (the mean of the gradient differences is 0.1 mm with a standard deviation of 0.7 mm), despite the differences in the processing strategy (double-differences for GAMIT/GLOBK versus zero-difference for GIPSY-OASIS).We also observe that gradient amplitudes are correlated with the seasonal behaviour of the humidity. Like ZWD estimates, they are larger in summer than in winter. Their directions are stable over the time but not correlated with the IWV anomaly observed by ERA-Interim. Tropospheric gradients observed at many sites always point to inland throughout the year. These preferred directions are almost opposite to the largest slope of the local topography as derived from the world Digital Elevation Model ASTER GDEM v2. These first results give a physical meaning to gradients but the origin of such directions need further investigations.

Assessment of modernized GPS L5 SNR for ground-based multipath reflectometry applications

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Natural formations at the Earth-Moon triangular point in perturbed restricted problems

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A numerical study of powered Swing-Bys around the Moon

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

O monitoramento climático e o alerta de desastres naturais na era da comunicação digital

This article presents considerations concerning the interaction between communication and digital platforms and applications developed to perform computerized climate monitoring and issue alerts about natural disasters. From work in the Center for Integrated Natural Disaster Alert (CIADEN), which processes meteorological data provided by Platform Monitoring, Analysis and Warning TerraMA2 designed by the National Institute for Space Research (INPE) to conduct monitoring and fi ring warning about climate risk environment, we propose the expansion of interactivity with the various possibilities of digital communication available today for signifi cant portion of society. On another front, the CIADEN has articulated teaching and research on climate monitoring and warning of natural disasters, weather, and geoprocessing environment, involving teachers and students both in school and in higher and technical.

Análise do conflito do uso e ocupação da terra em área de preservação permanente através do SIG

This study aimed to map the classes of use and occupation and their conflicts in Areas of Permanent Preservation (APPs) in the basin of Ribeirão São Pedro - Botucatu (SP) with the use of remote sensing techniques - image obtained by satellite 2011 - and the use of GIS. For this, we used the GIS techniques, and the integration of information held in the Geographic Information System (GIS) - IDRISI, coupled with the use of digital maps, published by the Brazilian Institute of Geography and Statistics - IBGE, scale 1: 50,000 and satellite images LANDSAT - 5 (2011) sensor TM (Thematic Mapper) with spatial resolution of 30 x 30 meters, provided by the National Institute for Space Research (INPE) .The Geographic Information System (GIS) was used IDRISI Selva and software, CartaLinx. This work had as legal support environmental legislation, specifically, the Federal Law 12.651 / 12. Thus, the study of the watershed becomes an important tool to understand its dynamics in relation to the use and occupation of their area and to characterize their environmental problems and taking as legal counsel to the preservation and conservation of the land to support environmental legislation.

Caracterização de conflitos de uso do solo em apps na bacia hidrográfica do córrego barra seca (pederneiras/sp)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)