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.

Geomorphic relationships characteristic of the region between the Billefjorden and Austfjorden display a high degree of complexity. The relationships result from palaeogeographical changes which took place during the Late Pleistocene and Holocene. A topographic expression is the product of glacial, marine and lacustrine processes. In view of the gathered observational information and the 14C date of 8.120+60 ɣr BP (Gd-1900) provided in 1987 on marine shells found in glacial deposits between Hoglandvatnet and Alandvatnet, inferences can be made as to a large extent of marine processes in the study area during the maior part of the tarlier Holocene.

The paper presents the theoretical background, computer model, laboratory measurements and SPICE simulation results of a 323 W, 1 MHz Class E inverter operating with an efficiency of 97%. The inverter is built around a CoolMOS transistor from Infineon Technologies. The transistor belongs to a new generation of high quality, optimized for low conduction losses and high speed switching power MOSFET-s. The presented computer model of Class E inverter is based on a state-space description and allows computing the inverter parameters for the optimum operation. Its validity has been confirmed experimentally. The SPICE simulation of the inverter has been also carried out in order to obtain better agreement between measurement and calculation results.