A measurement apparatus includes an optical emitter, an optical detector, and a controller. The optical emitter emits irradiation light onto a region. The optical detector detects scattered light from the region, the scattered light corresponding to the irradiation light. The controller causes first irradiation light of a first intensity and second irradiation light of a second intensity lower than the first intensity to be emitted from the optical emitter. The controller detects a predetermined signal on the basis of first scattered light detected by the optical detector in accordance with the first irradiation light and second scattered light detected by the optical detector in accordance with the second irradiation light.
