Orbit Determination
Mostrando 1-12 de 20 artigos, teses e dissertações.
-
1. Satellite Inertia Parameters Estimation Based on Extended Kalman Filter
ABSTRACT: The moment of inertia parameters play a critical role in assuring the spacecraft mission throughout its lifetime. However, determination of the moment of inertia is a key challenge in operating satellites. During satellite mission, those parameters can change in orbit for many reasons such as sloshing, fuel consumption, etc. Therefore, the inertia
J. Aerosp. Technol. Manag.. Publicado em: 28/03/2019
-
2. Comparison of the Incident Solar Energy and Battery Storage in a 3U CubeSat Satellite for Different Orientation Scenarios
ABSTRACT In CubeSats, because the size is limited, the estimation of the incident solar energy according to the orbital parameters and satellite attitude is more critical for the design process of the electrical power system. This estimation is helpful either for sizing of the power sources and energy storage or for defining the operation modes of the CubeSa
J. Aerosp. Technol. Manag.. Publicado em: 2016-03
-
3. Analyzing the Unscented Kalman Filter Robustness for Orbit Determination Through Global Positioning System Signals
ABSTRACT: The nonlinear unscented Kalman filter (UKF) is evaluated for the satellite orbit determination problem, using Global Positioning System (GPS) measurements. The assessment is based on the robustness of the filter. The main subjects for the evaluation are convergence speed and dynamical model complexity. Such assessment is based on comparing the UKF
J. Aerosp. Technol. Manag.. Publicado em: 2013-12
-
4. Orbit determination modeling analysis by GPS including perturbations due to geopotential coefficients of high degree and order, solar radiation pressure and luni-solar attraction
Abstract The purpose of this paper was to analyze the modeling of an artificial satellite orbit, using signals of the GPS constellation and least squares algorithms as the method of estimation, with the aim of analyzing the performance of the orbit estimation process. One pursues to verify how differences of modeling can affect the final accuracy of orbit de
J. Aerosp. Technol. Manag.. Publicado em: 2011-04
-
5. Determinação de órbita e manobras utilizando GPS e motor com baixo empuxo / Orbit determination and autonomous maneuver using GPS and low thrust
The Global Positioning System (GPS) is a satellite navigation system that allows the users to determine 3D positioning and the time with high precision. Its main purposes are: aid to radionavigation in three dimensions with high precision positioning, navigation in real time, global coverage and quick acquisition of data sent by the GPS satellites. In this w
Publicado em: 2008
-
6. Orbit determination and autonomous maneuver using GPS and low thrust / Determinação de órbita e manobras utilizando GPS e motor com baixo empuxo
O Sistema de Posicionamento Global (GPS) é um sistema de navegação por satélites que permite determinar o posicionamento tridimensional e tempo com alta precisão. Seus principais objetivos são: auxílio a radionavegação, navegação em tempo real, cobertura global e rápida aquisição de dados enviados pelos satélites GPS. Propõe-se neste trabalho
Publicado em: 2008
-
7. Real time orbit determination using GPS navigation solution
This work analyses a real time orbit estimator using the raw navigation solution provided by GPS receivers. The estimation algorithm considers a Kalman filter with a rather simple orbit dynamic model and random walk modeling of the receiver clock bias and drift. Using the Topex/Poseidon satellite as test bed, characteristics of model truncation, sampling rat
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2007-09
-
8. Determinação de órbita via GPS considerando modelo de pressão de radiação solar para o satélite topex/poseidon / Orbit determination using GPS considering solar radiation pressure model for the topex/poseidon satellite
Foi determinada a órbita de um satélite artificial, utilizando sinais da constelação GPS e o Método de Mínimos Quadrados Recursivo através de ortogonalizações de Givens como técnica de estimação, por ser um método mais robusto e mais rápido. A motivação era melhorar o desempenho de processos de determinação de órbitas e, ao mesmo tempo, mi
Publicado em: 2007
-
9. Determinação de órbita via GPS considerando modelo de pressão de radiação solar para o satélite topex/poseidon / Orbit determination using GPS considering solar radiation pressure model for the topex/poseidon satellite
Foi determinada a órbita de um satélite artificial, utilizando sinais da constelação GPS e o Método de Mínimos Quadrados Recursivo através de ortogonalizações de Givens como técnica de estimação, por ser um método mais robusto e mais rápido. A motivação era melhorar o desempenho de processos de determinação de órbitas e, ao mesmo tempo, mi
Publicado em: 2007
-
10. Orbital evolution and maneuvers around non-spherical bodies / Evolução orbital e manobras em torno de corpos não-esféricos
In the last years several asteroids had their shapes identified using images from space probes or through the indirect radar data determination. In a general way, these asteroids have forms quite different from spherical. Conventional spherical harmonic representations of the gravitational potential of such bodies require expansions of high degree and order,
Publicado em: 2006
-
11. EFEITOS DE DIFERENTES REGIÕES URBANAS NA PROPAGAÇÃO DE SINAIS DE SISTEMAS DE COMUNICAÇÕES PESSOAIS BASEADOS EM REDES DE SATÉLITES NÃO GEOESTACIONÁRIOS / EFFECTS OF DIFFERENT URBAN ENVIRONMENTS ON THE PROPAGATION OF SIGNALS FROM PERSONAL COM. SYSTEMS BASED ON NON GEOSTATIONARY ORBIT SATELLITE NETWORKS
As land-mobile satellite systems and radio-determination systems get more importance in the global telecommunications scenario, it becomes even more necessary to understand the radio-propagation environment: its behavior and the inter-relationship between its several aspects and physical parameters. Due to the communications devices characteristics used in t
Publicado em: 2005
-
12. Determination of zygomatic implants length based on computed tomography-establishment of a protocol / Determinação do comprimento de implantes zigomaticos a partir de tomografia computadorizada : estabelecimento de um protocolo
Zygomatic fixations offer an alternative to bone grafts in the rehabilitation of severely atrophic maxillas. Zygomatic implants are three to four times longer than conventional implants, and their positioning requires extreme surgical precision and skill, since they must be inserted in the maxillary sinus and their locking point is situated in the body of th
Publicado em: 2005