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A Modification to the Ionospheric Correction Method Used in Gps Radio Occultation : Volume 8, Issue 1 (27/01/2015)

By Healy, S. B.

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Book Id: WPLBN0004000360
Format Type: PDF Article :
File Size: Pages 25
Reproduction Date: 2015

Title: A Modification to the Ionospheric Correction Method Used in Gps Radio Occultation : Volume 8, Issue 1 (27/01/2015)  
Author: Healy, S. B.
Volume: Vol. 8, Issue 1
Language: English
Subject: Science, Atmospheric, Measurement
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Publication Date:
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications


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Culverwell, I. D., & Healy, S. B. (2015). A Modification to the Ionospheric Correction Method Used in Gps Radio Occultation : Volume 8, Issue 1 (27/01/2015). Retrieved from

Description: European Centre for Medium-range Weather Forecasts (ECMWF), Reading, UK. A modification to the standard bending angle correction used in GPS radio occultation is proposed. The modified approach should reduce systematic residual ionospheric errors in GPS radio occultation climatologies. A new second order term is introduced in order to account for a known source of systematic error, which is generally neglected. The new term has the form Κ(a) × (ΑL1 (a)-ΑL1(a))2, where a is the impact parameter, and (ΑL1, ΑL2) are the L1 and L2 bending angles, respectively. The variable κ is a weak function of impact parameter, a, but it does depend on a priori ionospheric information. The theoretical basis of the new term is examined. The sensitivity of κ to the assumed ionospheric parameters is investigated in one-dimensional simulations, and it is shown that Κ ≃ 10–20 rad−1. We note that the current implicit assumption is Κ = 0, and this is probably adequate for numerical weather prediction applications. However, the uncertainty in κ should be included in the uncertainty estimates for the geophysical climatologies produced from GPS-RO measurements. The limitations of the new ionospheric correction when applied to CHAMP measurements are noted. These arise because of the assumption that the refractive index is unity at the satellite, made when deriving bending angles from the Doppler shift values.

A modification to the ionospheric correction method used in GPS radio occultation

Ao, C. O., Mannucci, A. J., and Kursinski, E. R.: Improving GPS radio occultation stratospheric refractivity retrievals for climate benchmarking, Geophys. Res. Lett., 39, L12701, doi:10.1029/2012GL051720, 2012.; Aparicio, J. M. and Deblonde, G.: Imapct of the assimilation of CHAMP refractivity profiles in environment Canada global forecasts, Mon. Weather Rev., 136, 257–275, 2008.; Cucurull, L., Derber, J. C., Treadon, R., and Purser, R. J.: Assimilation of Global Positioning System radio occultation observations into NCEP's global data assimilation system, Mon. Weather Rev., 135, 3174–3193, 2007.; Danzer, J., Scherllin-Pirscher, B., and Foelsche, U.: Systematic residual ionospheric errors in radio occultation data and a potential way to minimize them, Atmos. Meas. Tech., 6, 2169–2179, doi:10.5194/amt-6-2169-2013, 2013.; Danzer, J., Gleisner, H., and Healy, S. B.: CHAMP climate data based on the inversion of monthly average bending angles, Atmos. Meas. Tech., 7, 4071–4079, doi:10.5194/amt-7-4071-2014, 2014.; Danzer, J., Healy, S. B., and Culverwell, I. D.: A simulation study with a new residual ionospheric error model for GPS radio occultation climatologies, Atmos. Meas. Tech. Discuss., 8, 1151–1176, doi:10.5194/amtd-8-1151-2015, 2015.; Gleisner, H. and Healy, S. B.: A simplified approach for generating GNSS radio occultation refractivity climatologies, Atmos. Meas. Tech., 6, 121–129, doi:10.5194/amt-6-121-2013, 2013.; Hajj, G. A. and Romans, L. J.: Ionospheric electron density profiles obtained with the G}lobal Positioning System: results from the {GPS/MET experiment, Radio Sci., 33, 175–190, 1998.; Hajj, G. A., Kursinski, E. R., Romans, L. J., Bertiger, W. I., and Leroy, S. S.: A technical description of atmospheric sounding by GPS occultation, J. Atmos. Sol.-Terr. Phy., 64, 451–469, 2002.; Healy, S. B. and Thépaut, J.-N.: Assimilation experiments with CHAMP GPS radio occultation measurements, Q. J. Roy. Meteor. Soc., 132, 605–623, 2006.; Kursinski, E. R., Hajj, G. A., Schofield, J. T., Linfield, R. P., and Hardy, K. R.: Observing earth's atmosphere with radio occultation measurements using the Global Positioning System, J. Geophys. Res., 102, 23429–23465, 1997.; Leroy, S. S., Anderson, J. G., and Dykema, J. A.: Testing climate models using GPS radio occultation: a sensitivity analysis, J. Geophys. Res., 111, D17105, doi:10.1029/2005JD006145, 2006.; Mannucci, A. J., Ao, C. O., Pi, X., and Iijima, B. A.: The impact of large scale ionospheric structure on radio occultation retrievals, Atmos. Meas. Tech., 4, 2837–2850, doi:10.5194/amt-4-2837-2011, 2011.; Poli, P., Moll, P., Puech, D., Rabier, F., and Healy, S. B.: Quality control, error analysis, and impact assessment of FORMOSAT-3/COSMIC in numerical weather prediction, Terr. Atmos. Ocean. Sci., 20, 101–113, 2009.; Poli, P., Healy, S. B., and Dee, D. P.: Assimilation of G}lobal Positioning System radio occultation data in the ECMWF {ERA-Interim reanalysis, Q. J. Roy. Meteor. Soc., 136, 1972–1990, doi:10.1002/qj.722, 2010.; Rennie, M. P.: The impact of GPS radio occultation assimilation at the Met Office, Q. J. Roy. Meteor. Soc., 136, 116–131.doi:10.1002/qj.521, 2010.; Steiner, A. K., Hunt, D., Ho, S.-P., Kirchengast, G., Mannucci, A. J., Scherllin-Pirscher, B., Gleisner, H., von Engeln, A., Schmidt, T., Ao, C., Leroy, S. S., Kursinski, E. R., Foelsche, U., Gorbunov, M., Heise, S., Kuo, Y.-H., Lauritsen, K. B., Marqua


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