It used to be, that people believed that the eye emitted invisible light rays that struck the world outside, causing it to become visible to the beholder. We now know that isn’t the case, but, that doesn’t mean it wouldn’t be a perfectly good way to see. In fact, that is the basic idea behind lidar, a form of digital imaging that’s proven very useful in everything from archeology to autonomous cars.Lidar

Lidar usually stands for ‘light detection and ranging’, though sometimes, it is referred to as light imaging detection and ranging and is also written in all caps. Most sources treat the word as an acronym. However, the term originated as a portmanteau of ‘light’ and ‘radar’. The first published mention was in 1963, by James Ring when he said, “Eventually the laser may provide an extremely sensitive detector of particular wavelengths from distant objects. Meanwhile, it is being used to study the moon by ‘lidar’ (light radar)”

That it sounds similar to sonar and radar is no coincidence; they all operate on the same principle: echolocation.  Echolocation is how bats find their way home.

Lidar originated in the early 1960’s, shortly after the invention of the laser.  It combined laser-focused imaging with the ability to calculate distances by measuring the time for a signal to return using appropriate sensors and data acquisition electronics. These light pulses – combined with other data recorded – generate precise, three-dimensional information about the shape and characteristics of the surface being measured.

Its first application came in meteorology, when the National Center for Atmospheric Research used it to measure clouds. In 1971, during the Apollo 15 mission is when the general public became aware of the accuracy and usefulness of lidar systems when the astronauts used a laser altimeter to map the surface of the moon.

Lidar data is often collected by air. The data collected supports activities such as inundation and storm surge modeling, hydrodynamic modeling, shoreline mapping, emergency response, hydrographic surveying, and coastal vulnerability analysis.

The instrument principally consists of a laser, a scanner, and a specialized GPS receiver.  Two types of lidar are: topographic and bathymetric. Topographic lidar typically uses a near-infrared laser to map the land, while bathymetric lidar uses water-penetrating green light to also measure seafloor and riverbed elevations.

With there being multiple components in one lidar unit, employing the services of Universe Optics is the perfect choice.  All the lenses necessary will be designed and manufactured with 100% precision, offering the clearest images possible for your specifications.

When lidar was first proposed in the 1960s, lasers and detection mechanisms were bulky and slow to operate. Today, thanks to shrinking electronics and the great speed of our computers, a lidar unit may send out and receive millions of pulses per second and complete hundreds of revolutions per second.

Lidar units on planes and helicopters can survey the terrain below quickly and accurately during flight; archaeologists can record every detail of a site down to the inch by sending a lidar unit through it; and most recently, a computer vision system in an autonomous car or robot can instantly acquaint itself with its surroundings.

This world of high-speed, high-precision computer perception is a complex and quickly evolving one, so lidar’s role may change as other technologies supersede it or expand its capabilities. But it seems likely that the ancient notion of vision, wrong as it was in 500 BC, is now here to stay.