A detection device includes a first sensor configured to transmit a first electromagnetic wave to a first range and receive the first electromagnetic wave reflected in the first range, a second sensor configured to transmit a second electromagnetic wave to a second range different from the first range and receive the second electromagnetic wave reflected in the second range, and a processor configured to calculate information on an object reflecting the first electromagnetic wave and the second electromagnetic wave based on a first signal output from the first sensor and a second signal output from the second sensor.