GPS Solutions

, Volume 7, Issue 2, pp 74–86 | Cite as

In-flight performance analysis of the CHAMP BlackJack GPS Receiver

Original Article
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Abstract

JPL's BlackJack receiver currently represents the most widely used geodetic grade GPS receiver for space applications. Using data from the CHAMP science mission, the in-flight performance of the BlackJack receiver has been assessed and the impact of various software updates performed during the 2.5 years since launch is described. Key aspects of the study comprise the channel allocation, anomalous data points, and the noise level of the code and carrier data. In addition, it has been demonstrated that the code measurements collected onboard the CHAMP satellite are notably affected by multipath errors in the aft-looking hemisphere, which can be attributed to cross-talk between the occultation antenna string and the primary precise orbit determination antenna. For carrier smoothed 10 s normal points, the code noise itself varies between a minimum of 5 cm at high elevations and 0.5 m (C/A) to 1.0 m (P1, P2) at 10° elevation. Carrier-phase data exhibit representative errors of 0.2 to 2.5 mm. The results of the CHAMP GPS data analysis contribute to a better understanding and possible improvement of the BlackJack receiver and support the design of optimal data editing and weighting strategies in precise orbit determination applications.

Keywords

CHAMP BlackJack Multipath Receiver noise 
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Notes

Acknowledgments

The present study makes use of Blackjack GPS receiver measurements that have been made available for the CHAMP science team by GFZ, Potsdam. Precise reference orbits of the CHAMP satellite have kindly been provided by J. van den Ijssel, DEOS. Tom Meehan, JPL, and Ludwig Grunwaldt, GFZ, have taken the initiative for deactivating the occultation antenna string as part of a test campaign to demonstrate its impact on code multipath. Their support in this matter is highly appreciated. The authors would furthermore like to thank Larry Young, JPL, for his valuable comments and technical discussions during preparation of the manuscript.

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Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  1. 1.German Space Operations CenterDeutsches Zentrum für Luft- und RaumfahrtWeßlingGermany
  2. 2.Delft Institute for Earth Oriented Space Research (DEOS)DelftThe Netherlands

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