Global Navigation Satellite Systems can provide position, velocity and time information to users using receiver hardware. The United States developed Global Positioning System (GPS) is the only current fully operational system; however further systems are in development. The GPS has shown considerable success for navigation, but it still has a number of problems that limit its accuracy. The two main problems are the ionosphere and local environment of the receiver. The ionosphere causes a delay and random rapid shifts in phase and amplitude (scintillation) to the signal. The local environment can provide the signal with multiple routes (multi-path) to the receiver. In this project a GPS signal simulator is developed, which models the effects of the ionosphere and multi-path on the modulated signals. The focus is made on the GPS system as the simulator measurements can be compared to the real measurements; however other systems will be considered in the future. A number of experiments investigating multi-path and ionospheric effects on a receiver’s ability to track the signals have been completed. The simulator has been used to replicate a real local multi-path environment and the results have been compared. Further investigations of the multi-path have shown a unique multi-path signature in the receiver power output. The later part of the thesis describes a case study investigating a short but rapid period of scintillation observed on three receivers based in Norway. An analysis of the multi-path environment was completed, but was found not to be the cause. The ionosphere was investigated using equipment based across Scandinavia. The equipment showed that geomagnetic conditions were disturbed at the time of the event. The GPS measurements were compared with all-sky camera data to show that the scintillation can be attributed to the GPS signal path crossing electron density structures associated with the aurora.

En la presente tesis titulada “Análisis y diseño de una aplicación guía personal para centros comerciales de la ciudad de Huancayo”, se aborda el problema referente a la orientación de los clientes dentro de un Centro comercial, así como respaldar su seguridad ante situaciones de emergencia, por lo cual el objetivo es analizar y diseñar una aplicación guía para centros comerciales de la ciudad de Huancayo, orientada a los aspectos comercial y seguridad. El aplicativo nativo desarrollado para dispositivos Android, aportará al centro comercial un canal de comunicación para difundir tiendas, ofertas o promociones de tiendas y eventos; también en ayudar a los clientes en casos de emergencias.

Este trabalho trata da proposta de um Sistema de Gestão da Qualidade para uma empresa genérica prestadora de serviços de posicionamento com o GPS, como alternativa para melhorar a gestão da organização e garantir a qualidade de seus serviços e produtos. O aumento da demanda por esse tipo de serviço estimulou o aparecimento de novas empresas específicas em GPS e adaptação de antigas para atender um mercado crescente e cada vez mais exigente. Por se tratar de um processo novo, sua implantação requer mudanças significativas tanto de ordem técnica (intimamente ligadas ao conhecimento específico do sistema e suas capacidades) como administrativa (meios e políticas que possam garantir uma gestão efetiva de todos os processos envolvidos no posicionamento com o GPS dentro da empresa). A modernização imposta ao setor de topografia e geodésia em seu cenário produtivo e econômico, com o aparecimento de novas técnicas produtivas e ferramentas gerenciais, não pode mais ser protelada. Isso impõe às organizações uma necessidade emergencial de mudança e grandes desafios, entre eles o de sua própria sobrevivência. A execução de um serviço de posicionamento com o sistema GPS consiste em uma seqüência de procedimentos práticos que, se forem bem executados, proporcionarão maior probabilidade de êxito ao resultado final. Os procedimentos dependem muito de cada caso, e normalmente são definidos por indicações dos fabricantes dos instrumentos, normas e especificações oficiais e, na grande maioria das vezes, pela própria experiência prática do responsável. Como parte desse trabalho foi desenvolvida uma pesquisa social para identificar como são e como agem as empresas que prestam serviços de posicionamento com o sistema GPS no Brasil. Com base nos resultados dessa pesquisa, elaborou-se uma empresa genérica de posicionamento com GPS, com características similares à maioria, e que serviu como referência na concepção dos padrões para os processos básicos da empresa. O modelo de gestão da qualidade proposto teve como guia o Sistema da Qualidade preconizado pela ISO série 9000. Consideraram-se também as ferramentas de gestão e controle da qualidade comumente aplicados na indústria de manufatura e adaptados aos serviços de um posicionamento com GPS. O resultado apresenta uma seqüência de implantação do modelo com as devidas recomendações e viabilidades. Para ilustrar, são apresentados os resultados benéficos obtidos com a aplicação direta dos padrões técnicos da empresa genérica, em um posicionamento real para pontos estáticos, em que se considerou apenas a parte produtiva. O resultado mostrou-se bastante convincente. / This thesis deals with a proposal for quality management for a generic GPS surveying company as an alternative to management and service quality improvement. As a result of the GPS measurement demand increasing, an important number of new companies and/or renovated ones have been established in order to operate in that market. But considering that it is a new process some changes must be performed in order to accommodate the old surveying techniques and the old fashioned management to the new reality. This implies in a new management organization which must be based on a well described procedure sequence aiming a final quality control success. As an important part of that research a social research has been applied to several Brazilian GPS service provider companies with the purpose of knowing the status of the sector related to the quality management. Based on that research a hypothetical company was considered in order to give subsides to the elaboration of a standardized company. The proposed quality management model was based on the ISO 9000 Quality System adopting management tools and quality control operators applied in the general industry adapted to the GPS surveying companies. This thesis shows the results of that research presenting an implementation model for quality management considering a real surveying GPS work based on the new GPS measurement techniques.

Magíster en Ciencias, Mención Geofísica / En la presente tesis se procesan y analizan series de tiempo registradas a partir de datos de GPS de alta frecuencia (motogramas), para tres grandes terremotos de subducción ocurridos en Chile en los últimos 10 años: Tocopilla en 2007 (Mw 7.7), Maule en 2010 (Mw 8.8) e Iquique en 2014 (Mw 8.1), de esta forma se obtienen los desplazamientos asociados al movimiento cosísmico de estos terremotos. Este trabajo está dividido en tres partes principales: el procesamiento de datos de GPS de alta frecuencia, a fin de obtener las series de tiempo para cada terremoto estudiando cada parámetro que influye en el cálculo de la posición como son la elección de la estación de referencia y de los satélites que son utilizados. El post-procesamiento, con el cual se consigue la señal del terremoto removiendo o filtrando señales ajenas a este como pueden ser la señal sideral generada en cada una de las estaciones debido al efecto multicamino y el paso de ondas superficiales por la estación de referencia provocando un movimiento ficticio en los desplazamientos observados en las estaciones cinemáticas. Por último, en los casos en que un receptor GPS está instalado junto a un acelerómetro, se comparó la señal del acelerograma integrado a desplazamiento y el motograma. Además de los tres terremotos antes mencionados, se procesaron tres eventos de menor magnitud: Constitución en 2012 (Mw 7.0) réplica del terremoto de Maule 2010, Iquique en 2014 (Mw 7.6) y Tongoy 2013 (Mw 6.5). El procesamiento de estos eventos permitió obtener una estimación con respecto a la mínima magnitud para la cuál el GPS puede registrar un evento interplaca tipo thrust. Se concluye que para obtener un motograma, es necesario aplicar los filtros expuestos, obteniendo una señal que sólo muestre el proceso del terremoto, eliminando señales que puedan distorsionar el registro. A pesar de que los filtros ayudan a obtener una buena señal, la aplicación de estos filtros puede comprometer las altas frecuencias debido a la suma constructiva y destructiva que se reliza con las señales. La comparación entre el acelerograma integrado dos veces y el motograma muestra que, a frecuencias menores a 0.1 Hz, se comportan de manera similar. Por otra parte, el dominio que posee el acelerómetro en la banda de alta frecuencia y del GPS en las bajas frecuencias hace que sean instrumentos complementarios capaces de otorgar información importantes en los primeros segundos de ocurrido un terremoto.

<p>I present an application to visualization of GPS data and Linear Correlations and models. A collection of data for each vehicle is used to compute correlations. Deviating correlations can be indicative of a faulty vehicle.</p><p> The correlation values for each vehicle are computed with use linear regression algorithms using up to 4 signals in the data (with varied time window), and display the model parameters in a window next to the GPS map. Multiple measurements (multiple drive routes and multiple model parameters) are displayed at the same time, allowing tracking over time and comparison of different vehicles.</p><p> </p><p> The whole technique is demonstrated on three data which is set on first frame by user. The results are displayed with a java application and Google Map.</p>

No description available.

No description available.

Recent government regulations for Enhanced 911 locating of wireless handsets require accuracy to within 50 and 300 meters. Two technologies under consideration are triangulation using existing wireless base stations and location using global positioning satellites (GPS). Satellite positioning is the leading candidate, however, reception of GPS signals within large buildings is difficult and considerable research is devoted to this topic. Conventional GPS receivers require line of sight to at least four satellites and, under outdoor conditions, the expected signal level is about -160 dBW. Within large buildings, detection is very difficult because there is high thermal noise and some satellite signals can be attenuated to less than -185 dBW while others can suffer little attenuation. In order to construct the pseudo-ranges necessary for position finding, the receiver must synchronize to the incoming codephase of each satellite and must operate with substantial Doppler frequency offset caused by satellite motion.<p> This thesis investigates the application of a parallel non-coherent spread spectrum synchronizer previously implemented as a very-large-scale integration (VLSI) circuit. The circuit processes one millisecond of incoming signal and uses a segmented matched filter (SMF) by which the segmentation provides some tolerance to Doppler shift. The thesis presents simulation results of averaging for tens of seconds. Through simulation, the SMF is compared with a transversal matched filter (TMF) under conditions of no Doppler shift; coherent and non-coherent integration are discussed. The simulation is conducted at 290 K (17°C) such that the Boltzmann noise is -204 dBW/Hz, with a GPS signal bandwidth of 2 MHz and signal level of -185 dBW, and the receiver input signal-to-noise ratio (SNR) is -44 dB.<p> The SMF is applied using differing segment lengths to high-sensitivity GPS data from indoor and urban simulated GPS data. The results demonstrate the SMFs ability to tolerate Doppler frequency offsets while allowing for long integration times to detect the weak GPS signals.

The following dissertation partially gathers the research carried out within two projects of the DGICyT (Dirección General de Investigación Científica y Técnica, Spanish Government Department for Scientific and Technical Research) in the National Park of Doñana. The main objectives of those projects were to establish a reference frame for positioning within the Park and to determine an accurate geoid. This would allow obtaining orthometric heights derived from GPS observations, which are very useful in those studies regarding the hydrology and geohydrology of the area. The absence of the geoid model would lead to errors when determining the orthometric heights through ellipsoidal ones, due to the great geoid undulation gradient in this zone.The National Park of Doñana is a protected area due to its great ecological value. It is located in the SW coast of Spain, between Huelva and Sevilla, and it has an extension of 500 km2 approximately. Almost half of its territory is a wetland, covered with water during the humid season. Additionaly, there are several restricted areas. These circumstances difficult the field observations. The first part of the work focuses on the analysis of geodetic and levelling networks already established in the area. It is important to know the conditions and accuracy of these networks, since they will become the base for the network instilled in the inner zone of the Park. The network was used initially when adjusting the different geoid models and later when computing a new model. The local network was linked to the Spanish national network (REGENTE) and to the highly precision levelling network (NAP). The adjustment of the gravimetric geoids IBERGEO95 and EGG97 in the zone was checked.Both were adjusted by means of GPS/levelling/gravimetric observations at some selected points, in two axis showing a N-S and E-W direction approximately, in order to control any directional variation.Checking the adjustment of IBERGEO95 and EGG97 allows to deduce that there is no guarantee of centimetre accuracy within the Park. Thus, a geometric geoid was computed by means of the remove-restore technique, using for that purpose: the global model CG01, obtained from the combined solution of earth data and data coming from space missions CHAMP and GRACE; and the digital terrain model obtained by merging the MDT25 model (from the Instituto Geográfico Nacional, National Geographic Institute of Spain) and the bathymetric data of the zone (from the Instituto Hidrográfico de la Marina, Marine Hydrogeographic Institute of Spain)The field data adquired within this work, as well as the geoid model obtained (namely Doñana 2005) will be of great help for the different studies regarding the superficial hydrology of the marshland and the tectonic and hydrogeological structure of the Park. These studies are currently being carried out and clearly show the inter-relationship among geodetic, geological and hydrogeological disciplines.

No description available.