caa a22 4500 475737318 CHVBK 20180406123450.0 cr unu---uuuuu 170329e20000201xx s 000 0 eng 10.1007/s001900050005 doi (NATIONALLICENCE)springer-10.1007/s001900050005 Residual errors in altimetry data detected by combinations of single- and dual-satellite crossovers [Elektronische Daten] [J. Klokočník, C. A. Wagner, J. Kostelecký] Abstract.:  The single- and dual-satellite crossover (SSC and DSC) residuals between and among Geosat, TOPEX/Poseidon (T/P), and ERS 1 or 2 have been used for various purposes, applied in geodesy for gravity field accuracy assessments and determination as well as in oceanography. The theory is presented and various examples are given of certain combinations of SSC and DSC that test for residual altimetry data errors, mostly of non-gravitational origin, of the order of a few centimeters. There are four types of basic DSCs and 12 independent combinations of them in pairs which have been found useful in the present work. These are defined in terms of the 'smean' and 'svariable' components of a satellite's geopotential orbit error from Rosborough's 1st-order analytical theory. The remaining small errors, after all altimeter data corrections are applied and the relative offset of coordinate frames between altimetry missions removed, are statistically evaluated by means of the Student distribution. The remaining signal of 'snon-gravitational' origin can in some cases be attributed to the main ocean currents which were not accounted for among the media or sea-surface corrections. In future, they may be resolved by a long-term global circulation model. Experience with two current models, neither of which are found either to cover the most critical missions (Geosat & TOPEX/Poseidon) or to have the accuracy and resolution necessary to account for the strongest anomalies found across them, is described. In other cases, the residual signal is due to errors in tides, altimeter delay corrections or El Niño. (Various examples of these are also presented.) Tests of the combinations of the JGM 3-based DSC residuals show that overall the long-term data now available are well suited for a gravity field inversion refining JGM 3 for low- and resonant-order geopotential harmonics whose signatures are clearly seen in the basic DSC and SSC sets. Springer-Verlag Berlin Heidelberg, 2000 Key words: Satellite altimetry - Single and dual crossovers - Student-t statistics nationallicence Klokočník J. Astronomical Institute, Czech Academy of Sciences, Ondřejov Observatory, CZ-251 65 Ondřejov, Czech Republic e-mail: jklokocn@asu.cas.cz, CZ aut Wagner C. A. NOAA, 1305 East-West Highway, Silver Spring, MD-20910, USA, US aut Kostelecký J. Faculty of Civil Engineering, TU Prague, Thákurova 7, CZ-160 00 Prague 6 and Research Institute of Geodesy, CZ-250 66 Zdiby, Czech Republic, CZ aut https://doi.org/10.1007/s001900050005 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s001900050005 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Klokočník J. Astronomical Institute, Czech Academy of Sciences, Ondřejov Observatory, CZ-251 65 Ondřejov, Czech Republic e-mail: jklokocn@asu.cas.cz, CZ aut NATIONALLICENCE 700 1- Wagner C. A. NOAA, 1305 East-West Highway, Silver Spring, MD-20910, USA, US aut NATIONALLICENCE 700 1- Kostelecký J. Faculty of Civil Engineering, TU Prague, Thákurova 7, CZ-160 00 Prague 6 and Research Institute of Geodesy, CZ-250 66 Zdiby, Czech Republic, CZ aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer