Patent attributes
A ranging apparatus is provided which is mountable to a vehicle and includes a transmitter, at least one detector, a light transmissive window, a heater, a snow accumulation condition determiner, a snowfall condition determiner, and a heater controller. The heater works to heat the transmissive window. The snow accumulation condition determiner determines a snow accumulation condition of a surface of the light transmissive window. The snowfall condition determiner determines a snowfall condition around the vehicle. The heater controller works to control energization of the heater depending upon the snow accumulation condition and the snowfall condition. The heater controller stops energizing the heater for a period of time when it is determined that there is neither the snow accumulation on the surface of the light transmissive window nor the snowfall around the vehicle.