were converted to the local topocentric frame (NEU).
The method of literature  is used to obtain the geocentric coordinates
of mobile nodes.
where [lambda] and [phi] denote the geocentric longitude and the geocentric latitude of radar, respectively, which can also be represented by geocentric coordinates
([x.sub.c] [y.sub.c] [z.sub.c]).
In the Baltic region, the territory being examined, we chose 1252, 1304, 1357, 1409, 1461, 1513, 1565, 1617 GPS data decisions (from the year 2004 to 2011) of geocentric coordinates
(X, Y, Z) of the GPS stations BOR1, HELG, LAMA, MAR6, METS, OSLS, POTS, RIGA, SASS, SULD, VIS0, and VLNS (Fig.
The evolution of ETRS89 geocentric coordinates
(X, Y, Z) is shown in Fig.
* using robust estimation after recognition made on the time series of geocentric coordinates
--completing the ..concentration" project, the result of which are about 35,000 of preliminarily newly stabilized concentration points with measured geocentric coordinates
. More details on concentration project see e.g.
If the Cartesian geocentric coordinates
[X.sub.i], [Y.sub.i], [Z.sub.i] of an object are known, it is possible to compute its geodetic coordinates [B.sub.i], [L.sub.i], [H.sub.i.sup.(g)] (Moritz 1990; Zakarevicius 1998).
As the result, time series of daily and sub-daily solutions (geocentric coordinates
) were determined.
[THETA]--common symbol for all geocentric coordinates
Results of individual CEGRN epoch observations are obtained in the form of vector geocentric coordinates
[X.sub.i] and their covariance matrix [[SIGMA].sub.i].
Daily geocentric coordinates
[X.sub.j](t) of subset of m (j = 1,2,...m, m [less than or equal to] n) selected stable stations will be further reduced for mean station position [X.sub.0j] at reference epoch [t.sub.0] and the a-priori station velocity [v.sub.0j] as