Abstract On 21 June 2010 the TerraSAR-X satellite was joined by the TanDEM-X satellite. A Global Positioning System (GPS) radio occultation (RO) experiment using the twin satellites has been carried out to estimate the precision of GPS atmospheric soundings. For the Day Of Year (DOY) 330–336, 2011, we analyze phase and amplitude data recorded by GPS receivers separated by a few hundred meters in a low earth orbit and derive collocated atmospheric refractivity profiles. In the altitude range 10–20km the standard deviation between TerraSAR-X and TanDEM-X refractivity does not exceed 0.15%. The standard deviation is rapidly increasing for lower and higher altitudes; close to the surface and at an altitude of 30km the standard deviation reaches 0.8% and 0.5%, respectively. Systematic deviations between TerraSAR-X and TanDEM-X refractivity in the considered altitude range (0–30km) are negligible. The results confirm the anticipated high precision of the GPS RO technique. However, the difference in the retrieved refractivity in the lower troposphere for different Open Loop (OL) signal tracking parameters, altered onboard TanDEM-X for DOY 49–55, 2012, calls for an in depth analysis. At the moment we can not exclude that a potential bias in the OL Doppler model introduces a bias in our retrieved refractivity at altitudes < 8 km.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Atmosphere sounding by GPS radio occultation: First results from TanDEM-X and comparison with TerraSAR-X


    Contributors:

    Published in:

    Advances in Space Research ; 53 , 2 ; 272-279


    Publication date :

    2013-11-01


    Size :

    8 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English







    TerraSAR-X Calibration - First Results

    Schwerdt, Marco / Bräutigam, Benjamin / Bachmann, Markus et al. | German Aerospace Center (DLR) | 2007

    Free access

    First TOPSAR interferometry results with TerraSAR-X

    Meta, Adriano / Prats, Pau / Steinbrecher, Ulrich et al. | German Aerospace Center (DLR) | 2007

    Free access