Measuring GNSS accuracy using SAPOS RTK network

Author:Renata Barradas Gutiérrez

Every year,the Council of European Geodetic Surveyors (CLGE)organisesa student contestaimed at rewarding young people for their work in various surveying-related areas. This year, theCLGE Students' Contestwas awarded at INTERGEO in Berlin on 27 September 2017.

The three categories awarded this year were:

• Geodesy and Topography,

• GIS, Mapping and Cadastre and

• Galileo, EGNOS, Copernicus.

Leica Geosystems had the pleasure to support the Geodesy and Topography Award.The awarding paper for this year’s category was: “一个investigation into the empirical accuracy of GNSS-NHN heights using SAPOS after the introduction of the GCG2016 as a component of the integrated geodetic spatial reference 2016” by Vitaly Winter, Geodesy and Geoinformation student at the Faculty of Agriculture at University of Bonn, Germany. The awarded paper is a local and practical study which shows the opportunities and accuracy of geodetic GNSS receivers for cadastral and engineering surveying.

Theresearch displays for the first time the achievable accuracy ofSAPOS HEPS(Network-RTK) after the introduction of the new geospatial reference 2016in a scientific investigation using Leica Geosystems GNSS equipment.

The goals and objectives of the investigation were:

• To obtain an empirical accuracy value for GNSS-NHN-heights in a specific region

• Compare target and measured values

• Derive the accuracy of theQuasigeoid model GCG2016using Leica Geosystems GNSS receivers

• Determine factors on which the accuracy of height measurement depends on.

ALeica GS16 Self-Learning GNSS Smart Antennaand aLeica CS20 Field Controller通过与提供商SAPOS的网络RTK服务HEP连接来获得正常高度。138次测量了德国北莱茵 - 韦斯特法里亚的莱茵 - 塞格县的官方高度标记。收集的使用的数据类型包括有关正常高度，椭圆形高度，起伏值，DOP值和测量位置（持续时间）的有用信息。

The Leica Geosystems GNSS equipment played a crucial role in achieving the conclusive results of the investigation.“The hardware [of the Leica GS16 and CS20 Field Controller] is reliable and conveniently designed. On top of this, the software settings can be deeply customised to improve reliability and the workflow. The chosen equipment had to receive various satellite systems, such as GPS, GLONASS, Galileo and Beidou with a fast and stable communication,”said Winter.

The results of the investigation test the precise positioning of the Network RTK method used by the satellite positioning service (SAPOS). The observations concluded a high accuracy and precision of under one centimetre using Leica Geosystems GNSS solutions.“GNSS-technologies are continuously improving so the results of my investigation can be used for comparisons to future investigations or to similar investigations in other regions,”concluded Winter.

Right: The deviation of observations at a single control point showing how accurate the used equipment and services work under favourable conditions. Left:Deviations of the height-markers in the study area in a target-actual comparison.

The Leica GS16 and CS20 Field Controller used attached to a height marker.

For more information about this study, visit:http://www.clge.eu/news/index/150