In the present report worked out in the form of a communication the general description of course and realization of the scientifical and technical programmes of the VIth Expedition to the Polish Polar Station in the Hornsund fiord on Spitsbergen is given. The details of the programme and results of investigations on particulat items constitute already or will constitute within the next time a subject of special publications.
Permanent renewal of measurements of phenomena occuring on Earth sufrace — the main task of geodesy and cartography — is the important element of geodynamic studies of the Arctic and Antarctic regions. Insitute of Geodesy and Cartography participates in the program of research led by Polish Academy of Sciences for over 10 years, using conventional geodetic methods, as well as new types of data, acquired from satellite observations and through remote sensing techniques. This activity is evidenced by setting-up astronomical main points close to Hornsund Station in 1958, as well as at Arctowski Station in 1976, where cyclic astronomical and satellite measurements were performed on these points. Geodynamic test site was organized in the Hornsund Region. As a result of these works numerous topographic and thematic maps were produced and many scientific publications were prepared by Institute specialists.
Time series of weekly and daily solutions for coordinates of permanent GNSS stations may indicate local deformations in Earth’s crust or local seasonal changes in the atmosphere and hydrosphere. The errors of the determined changes are relatively large, frequently at the level of the signal. Satellite radar interferometry and especially Persistent Scatterer Interferometry (PSI) is a method of a very high accuracy. Its weakness is a relative nature of measurements as well as accumulation of errors which may occur in the case of PSI processing of large areas. It is thus beneficial to confront the results of PSI measurements with those from other techniques, such as GNSS and precise levelling. PSI and GNSS results were jointly processed recreating the history of surface deformation of the area of Warsaw metropolitan with the use of radar images from Envisat and Cosmo- SkyMed satellites. GNSS data from Borowa Gora and Jozefoslaw observatories as well as from WAT1 and CBKA permanent GNSS stations were used to validate the obtained results. Observations from 2000–2015 were processed with the Bernese v.5.0 software. Relative height changes between the GNSS stations were determined from GNSS data and relative height changes between the persistent scatterers located on the objects with GNSS stations were determined from the interferometric results. The consistency of results of the two methods was 3 to 4 times better than the theoretical accuracy of each. The joint use of both methods allows to extract a very small height change below the level of measurement error.