PURPOSE: To facilitate the processing for the on-satelite mounted sensor data and reduce deflection of the image of a stereoscopic pair sensor in the prepara tion of a map, etc., by setting the machine axial direction of a satelite as the vector direction, by calculating the quantity of the rotation of the earth and controlling the machine axial direction of the satelite to the advance direction of the satelite measured on the earth.

CONSTITUTION: The difference between the timer information supplied from a timer device 5 and the Br passing time is counted by a data processing device 6, and the latitude of the satelite passing point is calculated, and the rotational speed of the earth at this latitude is calculated by the data processing device 6. Each deflection in the advance direction fixed on the satelite and the speed direction of the satelite in the coordinate system fixed on the earth is calculated by utilizing the attitude information supplied from an attitude gyro 4, rotational speed information of the earth, and the satelite speed information which is previously stored in the data processing device 6. A reaction wheel 7 is controlled so that the deflection information becomes zero and the attitude of the satelite is set so that the advance axis coincides with the advance direction of the satelite in the coordinate system fixed on the earth.