[en] Environmental sampling is the key method of the IAEA in searching signatures of a covert nuclear programme. However, it is not always easy to know the exact location of the sampling site. The satellite navigation system, utilizing a small receiver (GPS) and a PC, allows to have independent positioning data easily. The present task on the Finnish Support Programme was launched to create software to merge information about sampling and positioning. The system is build above a desktop mapping software package. However, the result of the development goes beyond the initial goal: the software can be used to real- time positioning in a mobile unit utilizing maps that can be purchased or produced by the user. In addition, the system can be easily enlarged to visualize data in real time from mobile environmental monitors, such as a Geiger counter, a pressurized ionisation chamber of a gamma-ray spectrometer. (orig.) (7 figs.)