Basic survey
As basic surveying in which is Geodesy and adjacent Geosciences the sum of those projects and Operate referred to which the base of the coordinate determination and the reference systems form. These include in particular:
- The determination of the reference ellipsoid (shape), its orientation and position in space (storage) or a fundamental point
- the measurement and calculation of the basic network ( triangulation , first-order network , GPS reference network, etc.)
- a large-scale precision leveling and the definition of a national height system (conversion of gravity potential values into meter measure)
- or the connection to a zero point such as B. the Amsterdam level (NAP), the Kronstadt level or earlier in Germany the normal high point in 1879 and normal high point in 1912
- Measurement of one or more scaling triangle sides ( baselines ); not required for GNSS measurements
- since around 1950 determination of a regional geoid
- a gravity network for gravimetric tasks
- since around 1970/80 the connection to a comprehensive, satellite-supported network of the zeroth order and the derivation of transformation parameters for the reference systems of the neighboring countries.
In Austria and Switzerland, responsibility for basic operations lies with the respective Federal Surveying Service ( BEV or state topography ), in Germany with the federal states , which, however, cooperate closely in this regard.
Network networks have been established internationally:
or by means of satellite geodesy and also for space travel
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Reference systems
- ITRS
- ETRF
- the Mercury date
- the IERS for the Earth's rotation
- Data services
- IGS
- IVS
- interdisciplinary the IGGOS observation system.