National height datum, the Gauss-Listing geoid level value w 0 and its time variation 0 (Baltic Sea Level Project: epochs 1990.8, 1993.8, 1997.4)

Estimation of the zero-height geopotential level W o LVD in a local vertical datum from inversion of co-located GPS, leveling and geoid heights: a case study in the Hellenic islands

“…An alternative estimation scheme based on the spheroidal free-air potential reduction at the LVD's zero-height level can be found in Grafarend and Ardalan (1997), Ardalan et al (2002) and Ardalan and Safari (2005).…”

“…Numerous such studies exist in the geodetic literature for different geographical regions, including the Baltic Sea countries (Grafarend and Ardalan 1997;Pan and Sjöberg 1998;Ardalan et al 2002), New Zealand (Amos and Featherstone 2009;Tenzer et al 2011), Iran (Ardalan and Safari 2005), Pakistan (Sadiq et al 2009), South-East Asia countries (Kasenda and Kearsley 2003), the North American Great Lakes (Jekeli and Dumrongchai 2003), and a multitude of other regional and national vertical datums (Rapp 1994;Burša et al 1999Burša et al , 2001Burša et al , 2004. The rationale of this approach is primarily suitable for single-LVD analysis, yet its simultaneous implementation over different geographical zones is also useful for unifying multiple LVDs with respect to a common reference surface that is specified either by a conventional W o value (Burša et al 2004) or through an external W o -free geoid model (Rapp 1994).…”

Effect of the GRACE satellite mission on gravity field studies in Fennoscandia and the Baltic Sea region

“…Intuitively, future high-resolution and more accurate global geoid models (can be treated as a world height system) create tools for unification of national height systems all over the globe. Discussion of unification of regional datums along with numerical verifications can be found, e.g., in Pan & Sjöberg (1998) and Ardalan et al (2002). The interest in unification of different national datums is twofold.…”

Avaliação da Superfície Equipotencial de Referência Local (W_0SP) no Estado de São Paulo

“…Segundo Hayden et al (2012), o valor do 0 foi calculado em muitas regiões do globo, utilizando-se de informações de altimetria por radar a bordo de satélites (exclui-se as regiões polares, ver Burša et al (1998); Sánchez (2009); Sánchez e Sideris (2017)). Outros pesquisadores como Grafarend e Ardalan (1997) e Ardalan et al (2002) determinaram o 0 local, utilizando-se de observações em marégrafos.…”