German Combined Quasigeoid 2016

Quasigeoid, reference ellipsoid and normal height

The German Combined Quasigeoid 2016 (GCG2016) is a quasigeoid model. It is part of the Integrated Spatial Reference 2016 and describes the height reference area of the national survey above the reference ellipsoid of the Geodetic Reference System 1980 (GRS 80).

Area of ​​validity Germany

The GCG2016 was developed jointly by the Working Group of the Land Surveying Administrations  (AdV), the Federal Agency for Cartography and Geodesy  (BKG) and the Institute for Earth Surveying of the University of Hanover  (IfE). It covers the entire area of ​​the Federal Republic of Germany including its exclusive economic zone in the North Sea.

values

With the help of the GCG2016, the physical normal heights in DHHN2016 can be calculated from the ellipsoidal heights in ETRS89 , which were determined by means of GNSS measurements and determined purely geometrically: ${\displaystyle H_{N}}$ ${\displaystyle h_{e}}$

${\displaystyle H_{N}=h_{e}-\zeta }$

The difference between ellipsoidal and normal height is called the height anomaly. It is also the difference between the reference ellipsoid and the quasigeoid, which is called the quasigeoid height. Its value in Germany is between 36 m and 50 m. ${\displaystyle \zeta }$

With regard to the height anomaly, the model shows a standard deviation of around 1 cm (in the Alps around 2 cm, on the North Sea up to 6 cm).

Investigation

The model is based on

• Severity measurements (severe disturbances, derived from 860,000 point severity values)
• Height anomalies (deviation between the ellipsoidal height and the normal height at about 470 points)
• Digital terrain models
• bathymetric data as well
• global geopotential models.

It was determined by averaging the independently performed calculations by BKG and IfE.

Consistency with other German surveying networks

As part of the Integrated Spatial Reference 2016 , the GCG2016 is consistent with the reference systems:

• ETRS89 / DREF91 (implementation 2016)
• German Main Elevation Network 2016 (DHHN2016) and
• German main gravity network 2016 (DHSN2016) .

Web links

• Online calculation of quasigeoid heights with the GCG2016
• Description of the GCG2016 at the IfE

Individual evidence

1. ↑ Quasigeoid GCG2016. Federal Agency for Cartography and Geodesy, accessed on August 30, 2017 . 
2. ↑ Quasigeoid of the Federal Republic of Germany. Federal Agency for Cartography and Geodesy, October 28, 2016, accessed on August 30, 2017 .