Studies of the interstellar medium using pulsar observations

One of the most important effects occurring during the propagation of the pulsar-emitted radio waves through the interstellar medium (ISM) is the temporal pulse broadening caused by the scattering of the signal on interstellar matter. Our latest studies of this phenomenon performed for the largest sample of pulsars ever used for this purpose, have shown that the amount of the observed pulse broadening strongly depends on the observing frequency. However, the slope of the dependence is different from the theoretical predictions based on simple scattering models of the turbulent ISM. Low frequency observations are crucial for the study of the scattering phenomenon, since it is at frequencies below a few hundred megahertz where the effects of scattering are the strongest. Therefore the newly constructed telescopes (such as LOFAR, MWA or LWA) and the future ones (such as SKA) that are working in this frequency range will be perfect instruments to study the ISM effects on pulsar radiation. In this field the progress can be made using smaller telescopes such as single stations of LOFAR. Here we present the first results of interstellar scattering observations using the PL-612 LOFAR station, located in Baldy near Olsztyn, Poland.