80
3 Non-geometry standards
points. The orientation of global Coordinate Referenee Systems is always an estimation beeause it is based on a number of well defined (but differently seleeted) referenee points where the residuals are minimised aeeording to an adjustment method.
Beeause the exaet geometrie relation between the Coordinate Referenee Systems is
not exaetly known, a transformation ean only be performed with an aeeuraey level
that eorresponds to the lowest aeeuraey of the definition of the system parts itself.
For example, if coordinates given in WGS84 (WGS84 ellipsoid) are needed in the
German Gauss-Krüger System (Bessei ellipsoid), they must be transformed.
Z
zero meridian
loeal meridian
r-------~----~~~--+_----~~+_--~~y
equator
Fig. 3.11. Ellipsoidal and Cartesian eoordinate system (IS043 2003)
Fig. 3.12. Ellipsoidal and projeeted Coordinate Referenee System (CRS)
Example: Universal Transverse Mereator Projeetion (UTM) with strips 6° wide in
longitude (Kniekmeyer 2003)
3 Non-geometry standards
points. The orientation of global Coordinate Referenee Systems is always an estimation beeause it is based on a number of well defined (but differently seleeted) referenee points where the residuals are minimised aeeording to an adjustment method.
Beeause the exaet geometrie relation between the Coordinate Referenee Systems is
not exaetly known, a transformation ean only be performed with an aeeuraey level
that eorresponds to the lowest aeeuraey of the definition of the system parts itself.
For example, if coordinates given in WGS84 (WGS84 ellipsoid) are needed in the
German Gauss-Krüger System (Bessei ellipsoid), they must be transformed.
Z
zero meridian
loeal meridian
r-------~----~~~--+_----~~+_--~~y
equator
Fig. 3.11. Ellipsoidal and Cartesian eoordinate system (IS043 2003)
Fig. 3.12. Ellipsoidal and projeeted Coordinate Referenee System (CRS)
Example: Universal Transverse Mereator Projeetion (UTM) with strips 6° wide in
longitude (Kniekmeyer 2003)