Gravity recovery using COSMIC GPS data: Application of orbital perturbation theory

Chein-way Hwang*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


COSMIC is a joint Taiwan-US mission to study the atmosphere using the Global Positioning System (GPS) occultation technique. Improved formulas are developed for the radial, along-track, and cross-track perturbations, which are more accurate than the commonly used order-zero formulas. The formulas are used to simulate gravity recovery using the geodetic GPS data of COSMIC in the operational phase. Results show that the EGM96 model can be improved up to degree 26 using 1 year of COSMIC data. TOPEX/POSEIDON altimeter data are used to derive a temporal gravity variation. COSMIC cannot reproduce this gravity variation perfectly because of data noise and orbital configuration, but the recovered field clearly shows the gravity signature due to mass movement in an El Niño.

Original languageEnglish
Pages (from-to)117-136
Number of pages3
JournalJournal of Geodesy
Issue number2-3
StatePublished - 19 Jun 2001


  • El niño
  • GPS
  • Orbit perturbation
  • Temporal gravity variation


Dive into the research topics of 'Gravity recovery using COSMIC GPS data: Application of orbital perturbation theory'. Together they form a unique fingerprint.

Cite this