HR: 1330h
AN: G52C-0048    [PDF]
TI: The effect of the second order GPS ionospheric correction on receiver positions
AU: * Kedar, S
EM: Sharon.Kedar@jpl.nasa.gov
AF: Jet Propulsion Laboratory Satellite Geodesy and Geodynamics Systems group, 4800 Oak Grove Dr. MS 238-600, Pasadena, CA 91109
AU: Hajj, G H
EM: George.A.Hajj@jpl.nasa.gov
AF: Jet Propulsion Laboratory Satellite Geodesy and Geodynamics Systems group, 4800 Oak Grove Dr. MS 238-600, Pasadena, CA 91109
AU: Wilson, B D
EM: Brian.D.Wilson@jpl.nasa.gov
AF: Jet Propulsion Laboratory Satellite Geodesy and Geodynamics Systems group, 4800 Oak Grove Dr. MS 238-600, Pasadena, CA 91109
AU: Heflin, M B
EM: Michael.B.Heflin@jpl.nasa.gov
AF: Jet Propulsion Laboratory Satellite Geodesy and Geodynamics Systems group, 4800 Oak Grove Dr. MS 238-600, Pasadena, CA 91109
AB: The Global Positioning System (GPS) transmits two frequencies, allowing users to correct for the first-order ionospheric signal group delay (or phase advance) of 1-50 m. The second-order ionospheric term, caused by the Faraday rotation effect induced by the Earth magnetic field, is about 1000 times smaller and usually ignored. In this study, we implement the 2nd-order correction suggested by Bassiri and Hajj [1993] and investigate its effect on GPS-inferred station positions. The correction causes a latitude dependent ~0.1-0.5 cm southward shift to the position which is roughly proportional to the integrated electron density above the receiver, and has strong diurnal, seasonal and decadal signatures. By analyzing a three-year time series of equatorial station positions obtained without the 2nd-order correction, a strong semi-annual north-south oscillation is observed, the origin of which has not been hitherto explained. We verify that this apparent oscillation can be largely removed once the 2nd-order correction is applied.
DE: 1214 Geopotential theory and determination
DE: 1223 Ocean/Earth/atmosphere interactions (3339)
DE: 1239 Rotational variations
DE: 1247 Terrestrial reference systems
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: 2003 Fall Meeting