Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 11, 6687-6699, 2011
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
13 Jul 2011
First results from the GPS atmosphere sounding experiment TOR aboard the TerraSAR-X satellite
G. Beyerle1, L. Grunwaldt1, S. Heise1, W. Köhler1, R. König1, G. Michalak1, M. Rothacher2, T. Schmidt1, J. Wickert1, B. D. Tapley3, and B. Giesinger4 1GFZ German Research Centre for Geosciences, Potsdam, Germany
2Swiss Federal Institute of Technology, Zurich, Switzerland
3Center for Space Research, University of Texas (UT-CSR), Austin, TX, USA
4Broad Reach Engineering, Tempe, AZ, USA
Abstract. GPS radio occultation events observed between 24 July and 17 November 2008 by the IGOR occultation receiver aboard the TerraSAR-X satellite are processed and analyzed. The comparison of 15 327 refractivity profiles with collocated ECMWF data yield a mean bias between zero and −0.30 % at altitudes between 5 and 30 km. Standard deviations decrease from about 1.4 % at 5 km to about 0.6 % at 10 km altitude, however, increase significantly in the upper stratosphere. At low latitudes mean biases and standard deviations are larger, in particular in the lower troposphere. The results are consistent with 15 159 refractivity observations collected during the same time period by the BlackJack receiver aboard GRACE-A and processed by GFZ's operational processing system. The main difference between the two occultation instruments is the implementation of open-loop signal tracking in the IGOR (TerraSAR-X) receiver which improves the tropospheric penetration depth in terms of ray height by about 2 km compared to the conventional closed-loop data acquired by BlackJack (GRACE-A).

Citation: Beyerle, G., Grunwaldt, L., Heise, S., Köhler, W., König, R., Michalak, G., Rothacher, M., Schmidt, T., Wickert, J., Tapley, B. D., and Giesinger, B.: First results from the GPS atmosphere sounding experiment TOR aboard the TerraSAR-X satellite, Atmos. Chem. Phys., 11, 6687-6699,, 2011.
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