PURPOSE: To make a data obtaining range symmetrical to the advance direction of a satellite, etc. by inserting a pulse delay device for varying an observing data obtaining start timing, into a data obtaining device loaded on a flying vehicle.

CONSTITUTION: An antenna 1 for obtaining a microwave radiation on the ground is inclined by an angle θ from an antenna revolving shaft 8, and rotates at a constant speed centering around the shaft 8. On the other hand, in order to keep the rotating speed of the antenna constant, a pulse generated in an oscillator 6 is divided by a frequency dividing circuit 7, the timing pulse train at suitable intervals is inputted to an antenna driving part 2 and controlled in phase. A microwave of the ground caught by the antenna 1 is received and demodulated by a receiving demodulator 3. Also, a calibrating part 4 generates the calibrating signal of a remote sensor. Said demodulating output and calibrating output are switched by a switching device 5, but as for its switching timing, a timing pulse generated in the frequency dividing circuit 7 is switched by delaying it by a delay time at a command signal C corresponding to the latitude on the ground, by a pulse delay device 16, by which a data obtaining place becomes symmetrical.