CORNEL PAUNESCU
Universitatea din Bucuresti, Facultatea de Geologie – Geofizica
UTILIZATION OF DIFFERENTIAL FORMULA FOR DETERMINING THE COORDINATES ON THE WGS ELLIPSOID
(Abstract)
This method could be used for the control of absolute values of the coordinates
determined by using GPS. The precision is not very high, but this is not necessary.
The computation of coordinates on WGS84 ellipsoid using differential formula
is important verifying the exactitude of GPS measuring.
In the ellipsoidal geodesy, the term "differential formula" is used
for the formulae expressing the coordinate variation of a point Si with the
quantity dBi, and dLi, as well as of the azimuth Ai of a geodetic line, with
the quantity dAi, after the modification of initial data of the geodetic network
(modification of geodetic coordinates of initial point Sl, of initial geodetic
azimuth Al and of length of the initial side sl) or of parameters of the reference
ellipsoid, "a" and "f", with the quantities da and df.
Several ways of solving the problem are offered by F. W. Bessel (1837), F.R.
Helmert (1886), W.K. Hristov (1957), F.N. Krasovski (1953) etc. The solution
are different, depending on the approximation degree accepted and, implicitly,
on the domain of applicability.
Key words: basic geodetic problem, differential formula, Krasovski ellipsoid,
WGS84 ellipsoid, geodetic network.