## 5 Conclusions  
Geodetic-glaciological field work for monitoring glaciers and ice sheets is necessary even in the age of satellite technology. On the one hand, it is for the verification of the satellite data, but on the other hand, they also provide important results of their own.  
The elevation changes determined during the Greenland Korth Expeditions (GKE) show a continuous melting process since 2002, mainly on the west coast. On the east side, the amount has increased from 20-40 cm/yr to 40-80 cm/yr. On the west side, the maximum annual ice loss has increased from 1.7 to 2.7 m/yr. Overall, the ice elevation at profile kilometer 100 has decreased by more than 35 m since 2002.  
It turns out that long-term observations are always needed to make claims about climate change. Our observations are based on a historically short period of time, about 100 years. Nevertheless, it can be argued that we are now observing an enormous melting of Arctic ice, especially on the west coast of Greenland. It is not the purpose here to discuss causes or consequences, although this may have far-reaching implications for climate change, a possible change in the Gulf Stream, sea level rise and thus a significant impact on humanity. The aim was to demonstrate the possible link between terrestrial static or kinematic GNSS measurement and data derived from the GLAS (Geoscience Laser Altimeter System) device onboard the ICESat-1 satellite and, next, to verify the reliability and accuracy of the digital surface model based on ICESat-1 satellite measurements. A relatively good agreement was achieved, the differences being due to the different resolutions and the different terms of observation of the Greenland ice sheet.  
Conceptualization, T.H. and L.N.; methodology, T.H. and L.N.; software, L.N.; validation, T.H. and L.N.; investigation, T.H; data processing, L.N. and T.H.; writing--original draft preparation, T.H., L.N. and K.P.; writing--review and editing, T.H., L.N. and K.P.; visualization, T.H. and L.N.; supervision, K.P.; project administration, T.H. and K.P. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Brandenburg University of Technology Cottbus-Senfenberg, Faculty of Architecture, Civil Engineering and Urban Planning. From the Czech part, the project was supported by a grant SGS22/049/OHKI1/1T/11.  
Not applicable.  
The used data were collected during the expeditions and from open sources.  
Our special thanks go to [PERSON], who initiated the scientific project and actively accompanied it for many years. Unfortunately, he died in an accident in 2019. He wasalways involved in the expeditions carried out until then and had the research and data in his hands. Furthermore, we thank [PERSON] from AllTerra Germany GmbH for the support with Trimble technology. Finally, we thank [PERSON] and [PERSON], our expedition members in 2020. From the Czech part, the project was supported by a grant SGS22/049/OHK1/1T/11.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.  
The following abbreviations are used in this manuscript:  
GIA \begin