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Mathematical Problems in Engineering
Volume 2007 (2007), Article ID 32514, 11 pages
http://dx.doi.org/10.1155/2007/32514
Research Article

Evaluation of Tropospheric and Ionospheric Effects on the Geographic Localization of Data Collection Platforms

1Division of Space Systems (DSE), National Institute for Space Research (INPE), São José dos Campos 12227-010, Brazil
2Division of Space Mechanics and Control (DMC), National Institute for Space Research (INPE), São José dos Campos 12227-010, Brazil
3Mathematics Department, DMA-FEG-UNESP, CP 205, Guaratinguetá 12500-000, Brazil

Received 29 September 2006; Accepted 23 April 2007

Academic Editor: José Manoel Balthazar

Copyright © 2007 C. C. Celestino et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The Brazilian National Institute for Space Research (INPE) is operating the Brazilian Environmental Data Collection System that currently amounts to a user community of around 100 organizations and more than 700 data collection platforms installed in Brazil. This system uses the SCD-1, SCD-2, and CBERS-2 low Earth orbit satellites to accomplish the data collection services. The main system applications are hydrology, meteorology, oceanography, water quality, and others. One of the functionalities offered by this system is the geographic localization of the data collection platforms by using Doppler shifts and a batch estimator based on least-squares technique. There is a growing demand to improve the quality of the geographical location of data collection platforms for animal tracking. This work presents an evaluation of the ionospheric and tropospheric effects on the Brazilian Environmental Data Collection System transmitter geographic location. Some models of the ionosphere and troposphere are presented to simulate their impacts and to evaluate performance of the platform location algorithm. The results of the Doppler shift measurements, using the SCD-2 satellite and the data collection platform (DCP) located in Cuiabá town, are presented and discussed.