Podrobnosti záznamu

Název
    Earth's dimension specified by geoidal geopotential
Údaj o odpovědnosti
    Milan Burša, Erwin Groten, Steve Kenyon, Jan Kouba, Karel Raděj, Viliam Vatrt, Marie Vojtíšková
Autor
    Burša, Milan, 1929-
    Groten, Erwin
    Kenyon, Steve
    Kouba, Jan
    Raděj, Karel
    Vatrt, Viliam
    Vojtíšková, Marie
Jazyk
    anglicky
Zdrojový dokument - seriál
    Studia geophysica et geodaetica
Svazek/č.
    Vol. 46, no. 1
Strany
    p. 1-8
Rok
    2002
Poznámky
    1 diagr., 1 tab.
    il.
    Obsahuje bibliografické odkazy
    Zkr. název ser.: Stud. geophys. geod. (Praha)
Klasifikační znak
    528
    55
    550.3
Skupina konspektu
    528
    55
Předmětová skupina
    geodézie
    geoid
    metody satelitové
    planeta Země
    světový výškový systém
    tvar Země
Geografické jméno
    Země
Klíčové slovo
    Dimension
    Earth's
    Geoidal
    Geopotential
    Specified
Abstrakt (anglicky)
   The TOPEX/POSEIDON (T/P) satellite altimeter data from January 1, 1993 to January 3, 200J (cycles 11 - 305) was used for investigating the long-term variations of the geoidal geopotential W0 and the geopotential scale factor R0 = GM/V/0 (GM is the adopted geocentric gravitational constant). The mean values over the whole period covered are W0 = (62 636 856.161+-0.002) mV2, R0 = (6 363 672.5448+-0.0002) m. The actual accuracy is limited by the altimeter calibration error (2 - 3cm) and it is conservatively estimated to be about+-0.5 m2s-2 (+-5 cm). The differences between the yearly mean sea surface (MSS) levels, came out as follows: 1993 -1994: -(1.2+-0.7) mm, 1994-1995: (0.5+-0.7) mm, 1995-1996: (0.5 +-0.7) mm, 1996-1997: (0.1+-0.7) mm, 1997-1998: -(0.5+-0.7) mm, 1998-1999: (0.0+-0.7) mm and 1999- 2000: (0.6+-0.7) mm. The corresponding rate of change in the MSS level (or R0) during the whole period of 1993 - 2000 is (0.02+-0.07) mm/y.
   The value W0 was found to be quite stable, it depends only on the adopted GM, w and the volume enclosed by surface W= W0. W0 can also uniquely define the reference (geoidal) surface that is required for a number of applications, including World Height System and General Relativity in precise time keeping and time definitions, that is why W0 is considered to be suitable for adoption as a primary astrogeodetic parameter. Furthermore, W0 provides a scale parameter for the Earth that is independent of the tidal reference system. After adopting a value for W0, the semi-major axis a of the Earth's general ellipsoid can easily be derived. However, an a priori condition should be posed first. Two conditions have been examined, namely an ellipsoid with the corresponding geopotential which fits best W0 in the least squares sense and an ellipsoid which has the global geopotential average equal to W0.
   It is demonstrated that both a-values are practically equal to the value obtained by the Pizzetti's theory of the level ellipsoid: a =(6 378 136.7+- 0.05) in
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    28. 3. 2008
Datum importu
    8. 8. 2012