Obituary for Prof. Dr. Hab. Wojciech Pachelski. Two years death anniversary

Fig. 1. Prof. Wojciech Pachelski Professor Wojciech Pachelski was born in April 1939 in Warsaw. He graduated the Warsaw Geodesic Secondary School and then the Faculty of Geodesy and Cartography of the Warsaw University of Technology in 1961. He worked as an assistant at the Institute of Geodesy and Cartography in 1961–1962, then (1962–1972) as an assistant professor at the Computing Center of the Polish Academy of Sciences in Warsaw. He defended his doctoral dissertation Some Solutions for Processing Observational and Orbital Numerical Data of Artificial Earth Satellites (Figure 2) at the Faculty of Geodesy and Cartography of the Warsaw University of Technology in 1966. Professor Tadeusz Trajdos, an outstanding Polish mathematician, a longtime employee of our University, was his thesis supervisor. Wojciech Pachelski, Ph.D. was employed at the Institute of Mathematical Machines in Warsaw (as an assistant professor – Head of Department) in 1972–1977. His work subjects included: applications of digital machines to the processing of satellite surveying and space experiments data; development of the sequential alignment method and its application to the experimental satellite triangulation network. In the following years (1977–2008) he worked as an assistant professor and professor (from 1994) at the Space Research Center of the Polish Academy of Sciences, where he continued research in the above fields. During this period, Professor Wojciech Pachelski’s textbooks for learning programming in Fortran – known all over Poland – were published. From these books, older MUT employees (including the author of this biography) learned Fortran IV programming for ODRA 1300 machines and Fortran 77.