EARTH SENSOR AND EARTH EDGE DETECTION METHOD USING EARTH SENSOR

PROBLEM TO BE SOLVED: To provide a small-sized and low cost earth sensor and an earth edge detection method using the earth sensor, suitable for mounting a small artificial satellite, in the present invention.SOLUTION: The earth sensor includes at least three earth edge detectors having a detection part including a plurality of thermopile elements arranged in a line shape or arranged in a skew in the vertical direction to the earth edge and a signal processing part for digitally converting and outputting a signal detected by the detection part, and can detect the earth edge 708 in arrangement of the thermopile elements, by determining arrangement De, Dn, Dw and Ds of the thermopile elements of becoming 1 in a digital value as an earth area 700 and arrangement of the thermopile elements of becoming 0 in the digital value as space, by being converted into the digital value with every thermopile element, by binarizing to a value of 0 or 1 with every thermopile element, by comparing an infrared radiation amount outputted with every thermopile element with a predetermined threshold value by the signal processing part.