Two methods of electron density retrieval from truncated ionospheric radio occultation data
Presenter:
Haixia Lyu
IEEC, Barcelona, Spain; UPC-IonSAT, Barcelona, Spain
1) IEEC, Barcelona, Spain 2) UPC-IonSAT, Barcelona, Spain 3) UPC-TALP, Barcelona, Spain 4) ICE-CSIC, Barcelona, Spain
Talk
Driven by the future EUMETSAT Polar System 2nd Generation, new processing strategies to deal with truncated Ionospheric Radio Occultation (IRO) measurements will be required to retrieve full electron density profiles. In spite of the previous efforts on discovering scale height above the peak linearly increasing with height (Olivares-Pulido, 2016) and the success in testing the good extrapolation performance by the Vary-Chap model (Hernández-Pajares, 2017), it is still a challenge to estimate electron density profiles with truncated IRO data, since the prerequisite of extrapolation, i.e. the accurate electron density estimation below the maximum observable impact parameter, cannot be ensured due to missing observations for a significant part of the RO measurements (more than 40%). In the framework of the EUMETSAT Radio Occultation Meteorology Satellite Application Facility (ROM SAF), and in cooperation with UPC colleagues, this problem has been attacked by two different methods, which are Simple Estimation of Electron density profiles from topside Incomplete RO data (SEEIRO) and Abel-VaryChap Hybrid modeling from topside Incomplete GNSS RO data (AVHIRO). Both of them are based on the Vary-Chap model. On the one hand, SEEIRO solves the problem by two step processing strategy (estimation of the electron density profile below 500 km and its extrapolation upwards with the Vary-Chap model) and needs less computation time. On the other hand, AVHIRO estimates the full electron density profile simultaneously and achieves more accurate results, yet at higher computational cost.
These two alternative approaches will be presented, together with their performance analysis and computational implications.
Olivares‐Pulido, G., Hernández‐Pajares, M., Aragón‐Àngel, À., & Garcia‐Rigo, A. (2016). A linear scale height Chapman model supported by GNSS occultation measurements. Journal of Geophysical Research: Space Physics, 121(8), 7932-7940.
Hernández‐Pajares, M., Garcia‐Fernàndez, M., Rius, A., Notarpietro, R., von Engeln, A., Olivares‐Pulido, G., Aragón-Àngel, À. & García‐Rigo, A. (2017). Electron density extrapolation above F2 peak by the linear Vary‐Chap model supporting new Global Navigation Satellite Systems‐LEO occultation missions. Journal of Geophysical Research: Space Physics, 122(8), 9003-9014.
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