Rain sensor, vehicle using the same, and method for controlling the vehicle

A rain sensor, comprising:

• a light transmitter configured to radiate light to a windshield of a vehicle;
• a light receiver configured to receive light reflected from the windshield to generate a reception light signal;
• a filter configured to filter out noise from the reception light signal;
• and
• a controller configured to determine a presence or absence of pollutant and a degree of pollution on the basis of the filtered reception light signal, and perform pollutant removing,
• wherein the light transmitter includes a total reflection light transmitter and a diffused reflection light transmitter, and wherein during short-term monitoring the controller compares each of an amount of total reflection reception light, which is received from the total reflection light transmitter and reflected, and an amount of diffused-reflection reception light, which is received from the diffused reflection light transmitter and reflected, with an amount of normal reception light of a normal state, so as to detect a difference among the amount of total reflection reception light, the amount of diffused-reflection reception light, and the amount of normal reception light, and detects an outdoor temperature, thereby detecting the presence or absence of the pollutant on the basis of the detected difference and the detected outdoor temperature.