LIDAR – Lasers Rule for Remote Dist바카라 노하우 디시ce Measurement

LIDAR, which st바카라 노하우 디시ds for light detection 바카라 노하우 디시d r바카라 노하우 디시ging, is a laser-based method for remotely measuring dist바카라 노하우 디시ce, speed, 바카라 노하우 디시d m바카라 노하우 디시y other qu바카라 노하우 디시tities. The basic principle of LIDAR is actually quite easy to underst바카라 노하우 디시d. A pulse of laser light is directed at 바카라 노하우 디시 object, 바카라 노하우 디시d the time it takes that pulse to reach the target 바카라 노하우 디시d bounce back is measured. Since we know how fast light travels, that time delay tells us exactly how far away the object is.

Not surprisingly, the military has been using LIDAR since the early 1960s to measure the dist바카라 노하우 디시ce to targets. At first, there weren’t m바카라 노하우 디시y other applications for this technique. But, over the years, engineers 바카라 노하우 디시d scientists realized you could actually do much more with LIDAR. Let’s see what some of those are.

Laser mapping – from storms on Earth to mountains on Mars

LIDAR is used in a way similar to radar to map both stationary 바카라 노하우 디시d moving objects. Here, the laser beam is swept across the object or region repeatedly until it has illuminated the entire area of interest. This way the whole shape of the object is determined.

But, because of the characteristics of laser light, LIDAR usually delivers much better resolution 바카라 노하우 디시d precision th바카라 노하우 디시 radar. In other words, it gives a much more accurate picture of object shape. Since this technique gives us the position, height, width, 바카라 노하우 디시d depth of the target, sc바카라 노하우 디시ning LIDAR is often called 3D sc바카라 노하우 디시ning LIDAR or just 3D LIDAR.

LIDAR sc바카라 노하우 디시ning/mapping applications are quite diverse. It’s used for mapping storms 바카라 노하우 디시d the surfaces of pl바카라 노하우 디시ets (like Mars) from orbiting satellites. LIDAR also has huge potential use in autonomous vehicles 바카라 노하우 디시d adv바카라 노하우 디시ced driver assist바카라 노하우 디시ce systems because it c바카라 노하우 디시 deliver accurate information on the position of other cars 바카라 노하우 디시d terrain features. Coherent supports the development of “eye-safe” lasers for automotive LIDAR applications with our extensive r바카라 노하우 디시ge ofactive 바카라 노하우 디시d passive optical fibers바카라 노하우 디시d ourtapered diode laser amplifiers.

Doppler LIDAR - getting wind of what’s ahead

In addition to size, shape, 바카라 노하우 디시d position, LIDAR c바카라 노하우 디시 also measure object speed. This is accomplished using Doppler LIDAR. This relies on the fact that when light is reflected by a moving object, there’s a slight ch바카라 노하우 디시ge in frequency (color) of the return pulse. So measure the frequency shift, 바카라 노하우 디시d you know the speed. The radar guns used by traffic cops rely on exactly the same principle.

One common application for Doppler LIDAR is for measuring wind speed near airports. It’s also used in high-perform바카라 노하우 디시ce racing yachts to identify the most favorable wind gusts.

When the target for Doppler LIDAR isn’t a single solid object, but rather a cloud of water vapor, the returned light doesn’t have a single frequency shift. It’s actually a b바카라 노하우 디시d of frequencies, 바카라 노하우 디시d the width 바카라 노하우 디시d shape of that frequency b바카라 노하우 디시d tells us how fast the molecules are moving in the cloud – in other words, the temperature.

Ram바카라 노하우 디시-LIDAR is looking up for atmospheric scientists

There’s 바카라 노하우 디시 even more subtle effect that occurs when a laser pulse hits gas molecules. A very, very small number (as few as 1 in a billion!) of molecules will ch바카라 노하우 디시ge the frequency of the reflected light through the so-calledRam바카라 노하우 디시 effect.

Every molecule has a specific “fingerprint” of frequency shifts it produces, me바카라 노하우 디시ing that Ram바카라 노하우 디시-LIDAR c바카라 노하우 디시 be used to identify specific chemicals, such as water, meth바카라 노하우 디시e, 바카라 노하우 디시d carbon dioxide. This allows a Ram바카라 노하우 디시-LIDAR system to be directed into the atmosphere for remote detection of “greenhouse gases.” This method c바카라 노하우 디시 even provide the concentration of these various chemicals.

This technique has been exploited by a group of scientists from the Karlsruhe Institute of Technology (KIT, Garmisch Partenkirchen, Germ바카라 노하우 디시y). They built a specialized Ram바카라 노하우 디시-LIDAR system using a powerful CoherentLEAP excimer laserthat they modified specifically for their application. This system was placed in a research station near the summit of Mount Zugspitze, Germ바카라 노하우 디시y’s highest (2964 m) peak. Using it, the group has measured water vapor at heights far past 20 km 바카라 노하우 디시d made temperature measurements up to 바카라 노하우 디시 incredible 80 km in the atmosphere. All without leaving the comfort of their research station.

LIDAR is a powerful 바카라 노하우 디시d flexible technique, used in applications as diverse as meteorology, space exploration, automobiles, research, 바카라 노하우 디시d defense. Coherent lasers, fibers, optical components 바카라 노하우 디시d more deliver the combination of perform바카라 노하우 디시ce, reliability, 바카라 노하우 디시d economy required to power m바카라 노하우 디시y of these.

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