PURPOSE: To realize a single region operation on the surface of the globe in a conical shape at a predetermined fixed incident angle by providing a cylindrical one-dimensional phased array antenna for receiving microwave noise from the surface of the globe.

CONSTITUTION: Microwave noise radiated from an object on the surface of the globe is received by an m.N sub-array in a cylindrical one-dimensional phased array antenna 1 comprising M.N radiation element array of a microwave radiometer mounted on a satellite. The radiation element array of the antenna 1 comprises M element arranged in the scanning direction and N elements arranged perpendicularly thereto and the m.N sub-array is selected by means of a sub-array selection switch 7. Since the radiation element array is arranged cylindrically in the scanning direction, conical single region operation on the surface of the globe can be realized by switching the sub-array sequentially.