OBSERVATORY UPICE APRIL 2011 CZECH REPUBLIC FREQUENCY 33 MHz OBSERVING PERIOD 33 MHz 1. - 30. 0500 1700 NO OBSERVATION 33 MHz APR FREQ STATION TYPE START TIME OF DUR FLUX DENS. REMARKS 2011 TIME MAXIMUM MIN PEAK MEAN UT UT NOT 33 UPIC NO EVENTS CALIBRATED