Editing Rain sensor (section)

== Principle of operation ==
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The rain sensor works on the principle of total internal reflection. An infrared light shone at a 45-degree angle on a clear area of the windshield is reflected and is sensed by the sensor inside the car. When it rains, the wet glass causes the light to scatter and a lesser amount of light gets reflected back to the sensor.

An additional application in professional satellite communications antennas is to trigger a rain blower on the aperture of the antenna feed, to remove water droplets from the [[BoPET|mylar]] cover that keeps pressurized and dry air inside the wave-guides.