POLRAD Experiment

An example of the AKR (Auroral Kilometric Radiation) recorded by the POLRAD radio-spectro-polarimeter. The 3 perpendicular components of the electric field are presented in the range from 4 kHz to 1 MHz, while crossing the morning sector of the auroral region (3.00 - 5.40 MLT) at the altitudes from 14441 to 18392 km. The lower limit of the AKR was at 150 kHz, while the maximum power was received at a typical range from 200 to 400 kHz.

White vertical strips seen every 2 min. 8 sec. come out from the time breaks resulting from periodic operation of the relaxation sounder. Well seen is the AKR modulation in the lower and middle panels, which is due to the spin of the spacecraft. The spin modulation can be used for direction finding of the AKR sources. Data from other 6 channels (not shown here) can be used to determination of the polarisation parameters.