On the Definition and Realization of a Global Vertical Datum
2011 (English)In: Journal of Geodetic Science, ISSN 2081-9943, Vol. 1, no 2, 154-157 p.Article in journal (Refereed) Published
A Global Vertical Datum (GVD) is naturally defined by the geoid, and there is a well-established consensus to adopt Gauss-Bessel-Listing's definition of the geoid (i.e. as being the level surface of the Earth's gravity field that best fits the undisturbed sea level). The main problem in defining the geoid is therefore to fix its constant geopotential (W00). Nevertheless, this definition can be interpreted as to fit either the geopotential of sea surface to a constant (W0), or to minimize the height of sea level with respect to the geoid. Although the two interpretations lead to apparently different solutions, we show that they are practically the same. To improve the estimation of W0, we propose to weight the included data according to their a priori error estimates.
Finally we discuss the use of GNSS/levelling data for vertical datum connections, concluding that such data, although indispensable for regional vertical datum connections, in combination with satellite altimetry over the oceans are practically useless for determining the GVD. Also, such a joint adjustment of the GVD and regional vertical datum biases yields inferior local connections vs. a separate adjustment with fixed GVD.
Place, publisher, year, edition, pages
Poland: Versita , 2011. Vol. 1, no 2, 154-157 p.
Global vertical datum, GVD, geoid, datum unification
Research subject SRA - E-Science (SeRC)
IdentifiersURN: urn:nbn:se:kth:diva-61334DOI: 10.2478/v10156-010-0018-zOAI: oai:DiVA.org:kth-61334DiVA: diva2:478923
FunderSwedish e‐Science Research Center
QC 201201192012-01-172012-01-172012-01-19Bibliographically approved