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

2007 ◽  
Vol 2007 ◽  
pp. 1-11 ◽  
Author(s):  
C. C. Celestino ◽  
C. T. Sousa ◽  
W. Yamaguti ◽  
H. K. Kuga
Keyword(s):  
Data Collection ◽  
Geographical Location ◽  
Geographic Location ◽  
Low Earth Orbit ◽  
Environmental Data ◽  
Collection System ◽  
Data Collection System ◽  
Doppler Shifts ◽  
Low Earth Orbit Satellites

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.

scholarly journals The Impact on Geographic Location Accuracy due to Different Satellite Orbit Ephemerides

2009 ◽  
Vol 2009 ◽  
pp. 1-9
Author(s):  
Claudia C. Celestino ◽  
Cristina T. Sousa ◽  
Wilson Yamaguti ◽  
Helio Koiti Kuga
Keyword(s):  
Data Collection ◽  
Geographic Location ◽  
Satellite Orbit ◽  
Environmental Data ◽  
Location Accuracy ◽  
Doppler Shifts ◽  
Precise Ephemeris ◽  
Doppler Data ◽  
Important Input ◽  
The Impact

The current Brazilian System of Environmental Data Collection is composed of several satellites (SCD-1 and 2, CBERS-2 and 2B), Data Collection Platforms (DCPs) spread mostly over the Brazilian territory, and ground reception stations located in Cuiabá and Alcântara. An essential functionality offered to the users is the geographic location of these DCPs. The location is computed by the in-house developed “GEOLOC” program which processes the onboard measured Doppler shifts suffered by the signal transmitted by the DCPs. These data are relayed and stored on ground when the satellite passes over the receiving stations. Another important input data to GEOLOC are the orbit ephemeris of the satellite corresponding to the Doppler data. In this work, the impact on the geographic location accuracy when using orbit ephemeris which can be obtained through several sources is assessed. First, this evaluation is performed by computer simulation of the Doppler data, corresponding to real existing satellite passes. Then real Doppler data are used to assess the performance of the location system. The results indicate that the use of precise ephemeris can improve the performance of GEOLOC by reducing the location errors, and such conclusion can then be extended to similar location systems.

Sign in / Sign up

Export Citation Format

Share Document