Geometric location of points on the Earth's surface, as well as satellite positions, are determined in the geocentric frame(conventionally it is related to the center of Earth mass), using cartesian, spherical or ellipsoidal coordinates
The mathematical model that was used considers that the LV has the shape of a TPS and is based on ellipsoidal coordinates
, leading the surface area calculation to depend on three spatial variables.
On the other hand, the unit dyadic in ellipsoidal coordinates
To obtain the solution of this problem it is convenient to introduce the planar ellipsoidal coordinates
([q.sub.1], [q.sub.2]) defined as
Through gathering the data from long period and processing them according to the highest standards, they give precise and reliable solutions (ellipsoidal coordinates
) of stations and enable reference systems realization.
where [phi], [lambda] are ellipsoidal coordinates
of the involved stations.
Deflection components determination consist in the comparison of astronomical coordinates: latitude and longitude and ellipsoidal coordinates
of the same point (Hofmann-Wellenhof and Moritz, 2006).