The word is an acronym for Light
Detection and Ranging. The US military and NASA invented the
Lidar technology during the early 1960s for measuring distance
in space. Its first commercial usage did not occur until 1995.
It uses ultraviolet, visible, or near infrared light from
lasers. Radar (Radio Detection and Ranging) uses radio or
electromagnetic waves. Lidar used in cars is low
powered and classed as 'eye-safe' allowing it to be used with
few safety precautions.
Some refer to Lidar as laser radar,
however it is not. It is more precise than radar, because the
speed of light is a constant, so a laser can make extremely
precise measurements of distance by computing the time between
when the device emits a laser pulse and when it detects the
reflection. Sound travels about 1,000 feet (300 meters) per
second and light travels about 984,000,000 feet per second
(300,000,000 meters). Also, radar wavelengths suffer from
atmospheric conditions, such as humidity, fog, rain, snow, and
temperature, but do perform better in smokey or dusty
conditions.
A laser unit fires a short pulse of light. The pulse rebounds
off a point, such as the rear of the car in front and is
detected by a sensor in the laser unit. A computer connected
to the unit measures the time between the initial pulse and
the light return and, using the speed of light, calculates the
distance the light has traveled. It creates a high-resolution
3D map of the surrounding environment. The best sensors can
see details of a few centimeters at distances of more than 330
feet or 100 meters.
Currently most autonomous cars use some combination of Lidar,
Radar, and camera. Lidar is precise, Radar is good at motion,
and cameras are good for depiction. Each technology has
strengths and weaknesses, so automakers and others are trying
to find the best combination of strengths at the lowest cost.
Showing posts with label Laser. Show all posts
Showing posts with label Laser. Show all posts
Jul 28, 2017
Nov 8, 2013
Laser Headlights are Coming
BMW is working on laser
(Light Amplification by Stimulated Emission of Radiation)
headlights to be introduced on selected 2014 models. They promise
to be much better than the relatively recent LED headlights. The
laser lights will put out more light and use two-thirds the power
of LEDs, which use one fourth the power of ordinary headlights.
They are also much more efficient and brighter than the current
Xenon headlights used on some cars. In addition, they are just 10
square micrometers and 1/10,000th the size of a
1-square-millimeter LED.
The inventor of the headlights says Laser lighting may even do away with household LED and CFL lighting before either takes off. These new Laser lights are also ideal for businesses, signage, and projectors used in movie theaters, as well as smartphone projectors. The Laser lights are different than you might think of a laser beam. These lights are diffused blue beams and reconstituted to a white specific width for use. There is no danger of an accident creating a beam that could be harmful to the naked eye.
Einstein came up with the theoretical foundation for lasers in 1917 and they were first demonstrated in 1947. They have been in use since then for various applications, but almost always as a concentrated beam.
It took from 1879, when the incandescent light began until a few years ago for radical change, now we have another whole new generation of lighting in about five years. In spite of the hype from manufacturers, it will likely be a few more years before we can buy one for our homes.
The inventor of the headlights says Laser lighting may even do away with household LED and CFL lighting before either takes off. These new Laser lights are also ideal for businesses, signage, and projectors used in movie theaters, as well as smartphone projectors. The Laser lights are different than you might think of a laser beam. These lights are diffused blue beams and reconstituted to a white specific width for use. There is no danger of an accident creating a beam that could be harmful to the naked eye.
Einstein came up with the theoretical foundation for lasers in 1917 and they were first demonstrated in 1947. They have been in use since then for various applications, but almost always as a concentrated beam.
It took from 1879, when the incandescent light began until a few years ago for radical change, now we have another whole new generation of lighting in about five years. In spite of the hype from manufacturers, it will likely be a few more years before we can buy one for our homes.
Sep 30, 2011
Ngrams
Google has digested over 15 million books to date and has come up with an interesting way to plot the usage of words over time. Ngrams are line charts that show the usage of words over time. Try some neologisms, like 'went missing' , which is relatively new to American English or laser, etc., to track when they came into everyday use. You can also pick two words to compare and you get to decide the time-line.
It does not filter out any words, including four letter words. It also has proper names. Think about interesting words and see how they relate to each other. There is a timeline on the bottom that lets you click to read the books used in the analysis. It is a fun way to pass some time and may be a site to bookmark so you can go back when a new word intrigues you, like extoplasm.
LINK
It does not filter out any words, including four letter words. It also has proper names. Think about interesting words and see how they relate to each other. There is a timeline on the bottom that lets you click to read the books used in the analysis. It is a fun way to pass some time and may be a site to bookmark so you can go back when a new word intrigues you, like extoplasm.
LINK
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