Although car manufacturers are marketing their cars as having ‘night vision’, it is not exactly true, if you are thinking of the military style goggles so often seen in Hollywood movies. Those night vision systems work by capturing small particles of light and increasing the brightness and then forming a picture, that is why they look like greenish blobs moving about a darkened background - in true total darkness (such as a cave system) they might be totally useless. But, we are all used to the night vision, so using is just a way to make us understand.
Instead, cars use a different way of detecting objects that may be ‘invisible’ due to lower light. They use thermal imaging, which is far more superior as it does not need an external light source, so if your headlights were out for some reason - maybe you hit a roo - the detection system would still be active.
How Night Vision in Cars Actually Work?
A car uses sensors that are capable of detecting thermal images, which is the short answer. But what are thermal images you might ask? Well, all it does this by sensing the electromagnetic radiation produced by heat. All forms of electromagnetic radiation have a specific wavelength pattern and when an instrument is tuned to receive those wavelengths it is able to create a picture of the world around it. It can tell how far things are away and in what direction.
The sensors a car is fitted with is known as ‘passive night vision’. The car has these sensors mounted on the front of the car, most often near the front bumper bar on behind the grille. They detect and analyze the heat from oncoming and passing objects like the car drives. The sensors are capable of detecting minute differences in the heat of objects around them, and it uses this information to build a virtual world of objects surrounding the car.
When the night vision system detects an oncoming object that may be in the path of your vehicle, it will usually alert you, and in some cases, it may take over the steering wheel and adjust the trajectory of the car so you do not have an accident. Of course, this is dependent on the exact system you have in your car, so it is best to check what the capabilities of your night vision system are.
Why Do I Need Night Vision Systems In My Car?
Driving at night is more dangerous than driving in the daytime, we are diurnal and our eyes are suited more for daylight, than operating at night. We need the light to see properly and therefore make informed decisions. When you take the light away it can be very hard for us to know what is going on around us, and using systems such as the night vision in a car can help us to see better. Think of them as a second set of headlights. The current ones are dim and not very effective, but when you chuck on a few spotlights and really light up the road, everything is much easier to see and you’ll feel more comfortable driving. Well, these are like a pair of 200W spotlights, you just can’t see them.
Night vision systems are excellent at spotting pedestrians, animals, and other living creatures. This is because they are detecting heat, and no light or movement, and living objects (especially mammals) are great at producing heat. For a thermal sensor a good and warm human body is like starting at the sun, almost so bright it needs to look away!
The best thing of all is that because the system does not need external light, it can work in pitch black situations. Think about driving on the lonely country road, with a new moon in the sky. The area just outside your headlights is nearly impossible to see. With night vision in your car, it can detect that cow or roo just resting on the road shoulder, waiting to ruin your night.