Ho, S.-P., G. Kirchengast, S. Leroy, J. Wickert, A. J. Mannucci, A. K. Steiner, D. Hunt, W. Schreiner, S. Sokolovskiy, C. O. Ao, M. Borsche, A. von Engeln, U. Foelsche, S. Heise, B. Iijima, Y.-H. Kuo, R. Kursinski, B. Pirscher, M. Ringer, C. Rocken, and T. Schmidt (2009a), Estimating the Uncertainty of using GPS Radio Occultation Data for Climate Monitoring: Inter-comparison of CHAMP Refractivity Climate Records 2002-2006 from Different Data Centers, J. Geophys. Res., doi:10.1029/2009JD011969.
Ho, S.-P., M. Goldberg, Y.-H. Kuo, C.-Z Zou, W. Schreiner (2009b), Calibration of Temperature in the Lower Stratosphere from Microwave Measurements using COSMIC Radio Occultation Data: Preliminary Results, Terr. Atmos. Oceanic Sci., Vol. 20, doi: 10.3319/TAO.2007.12.06.01(F3C). (Ranked one of the top 50 most popular papers in TAO)
Ho, S.-P., D. P. Edwards, J. C. Gille, M. Luo, G. B. Osterman, S. S. Kulawik, and H. Worden (2009c), A global comparison of carbon monoxide profiles and column amounts from Tropospheric Emission Spectrometer (TES) and Measurements of Pollution in the Troposphere (MOPITT), J. Geophys. Res., 114, D21307, doi:10.1029/2009JD012242.
He*, W., S.-P. Ho, H. Chen, X. Zhou, D. Hunt, and Y. Kuo (2009), Assessment of radiosonde temperature measurements in the upper troposphere and lower stratosphere using COSMIC radio occultation data, Geophys. Res. Lett., 36, L17807, doi:10.1029/2009GL038712.
Deeter M. N., D. P. Edwards, J. C. Gille, L. K. Emmons, G. Francis, S.-P. Ho, D. Mao, D. Masters, H. Worden, V. Yudin, and James R. Drummond (2009), The MOPITT version 4 CO product: Algorithm enhancements, validation, and long-term stability, J. Geophys. Res., 115, D07306, doi:10.1029/2009JD013005.
Ho, S.-P., W. He, and Y.-H. Kuo (2009d), Construction of consistent temperature records in the lower stratosphere using Global Positioning System radio occultation data and microwave sounding measurements, in New Horizons in Occultation Research, edited by A. K. Steiner et al., pp. 207–217, Springer, Berlin, doi:10.1007/978-3-642-00321-9_17.