Abel transform inversion of radio occultation measurements made with a receiver inside the Earth's atmosphere

Abstract. Radio occultation measurements made with a receiver inside the Earth’s atmosphere can be inverted, assuming local spherical symmetry, with an Abel transform to provide an estimate of the atmospheric refractive index profile. The measurement geometry is closely related to problems encountered when inverting seismic time-travel data and solar occultation measurements, where the Abel solution is well known. The method requires measuring both rays that originate from above and below the local horizon of the receiver. The Abel transform operates on a profile of "partial bending angles" found by subtracting the positive elevation measurement from the negative elevation value with the same impact parameter. In principle, the refractive index profile can be derived from measurements with a single frequency GPS receiver because the ionospheric bending is removed when the partial bending angle is evaluated. Key words. Atmospheric composition and structure (pressure, density and temperature) – Radio science (remote sensing)

[1]  J. Schofield,et al.  Observing Earth's atmosphere with radio occultation measurements using the Global Positioning System , 1997 .

[2]  S. Healy.  Radio occultation bending angle and impact parameter errors caused by horizontal refractive index gradients in the troposphere: A simulation study , 2001 .

[3]  George Antoine Hajj,et al.  A comparison of water vapor derived from GPS occultations and global weather analyses , 2001 .

[4]  J. R. Eyre,et al.  Retrieving temperature, water vapour and surface pressure information from refractive‐index profiles derived by radio occultation: A simulation study , 2000 .

[5]  D. Anderson,et al.  On the radio occultation method for studying planetary atmospheres , 1968 .

[6]  G. Kattawar,et al.  Unique temperature profiles for the atmosphere below an observer from sunset images. , 1997, Applied optics.

[7]  Gottfried Kirchengast,et al.  Sensitivity analysis for airborne sounding of the troposphere by GNSS radio occultation , 2002 .

[8]  X. Zou,et al.  Analysis and validation of GPS/MET data in the neutral atmosphere , 1997 .

[9]  A. Kliore,et al.  The neutral atmosphere of Venus as studied with the Mariner V radio occultation experiments , 1971 .

[10]  W. G. Melbourne,et al.  Initial Results of Radio Occultation Observations of Earth's Atmosphere Using the Global Positioning System , 1996, Science.

[11]  Rolf König,et al.  Atmosphere sounding by GPS radio occultation: First results from CHAMP , 2001 .

[12]  E. Robert Kursinski,et al.  A novel approach to atmospheric profiling with a mountain-based or airborne GPS receiver , 1999 .

[13]  E. H. Linfoot.  Principles of Optics , 1961 .

[14]  J. R. Eyre,et al.  A nonlinear optimal estimation inverse method for radio occultation measurements of temperature, humidity, and surface pressure , 2000, physics/0003010.

[15]  V. V. Vorob’ev,et al.  Estimation of the accuracy of the atmospheric refractive index recovery from Doppler shift measurements at frequencies used in the NAVSTAR system , 1994 .

[16]  W. G. Melbourne,et al.  The application of spaceborne GPS to atmospheric limb sounding and global change monitoring , 1994 .

[17]  Steven Businger,et al.  GPS Meteorology: Mapping Zenith Wet Delays onto Precipitable Water , 1994 .

[18]  Larry J. Romans,et al.  Ionospheric electron density profiles obtained with the Global Positioning System: Results from the GPS/MET experiment , 1998 .

[19]  Christian Rocken,et al.  Analysis and validation of GPS/MET radio occultation data in the ionosphere , 1999 .