Traditional Culture Encyclopedia - Weather inquiry - I want to make a device for driving in foggy days, which can judge the distance by infrared rays. What should I do?

I want to make a device for driving in foggy days, which can judge the distance by infrared rays. What should I do?

When my classmate was at school, he studied ultrasound. There is an acceptable sensor in the car behind him when the sound wave is reflected by the car in front or an obstacle. The distance between them can be measured by the time of going back and forth and the speed of sound waves, which can play a role in finding obstacles.

Let me give you an idea.