Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

LIDAR May Offer Peerless Precision for Remote Measures

27.05.2009
By combining the best of two different distance measurement approaches with a super-accurate technology called an optical frequency comb, researchers at the National Institute of Standards and Technology (NIST) have built a laser ranging system that can pinpoint multiple objects with nanometer precision over distances up to 100 kilometers.

The novel LIDAR (“light detection and ranging”) system could have applications from precision manufacturing lines on Earth to maintaining networks of satellites in perfect formation, creating a giant space-based platform to search for new planets.

LIDAR transmits light through the air and analyzes the weak reflected signal to measure the distance, or range, to the target. NIST’s new LIDAR, described in Nature Photonics,* has a unique combination of capabilities, including precision, rapid updates from multiple reference points at the same time, and minimal “measurement ambiguity.”

The system can update measurements to multiple targets simultaneously every 200 microseconds. Measurement ambiguity in a LIDAR system is due to the fact that, if the target is at long range from the instrument, the system can’t distinguish between two different distances that are multiples of its “ambiguity range.” The new NIST LIDAR has a comfortably large ambiguity range of at least 1.5 meters—large enough to check the coarse distance with widely available technologies such as GPS.

No other ranging system offers this combination of features, according to the new paper. NIST’s LIDAR could enable multiple satellites to maintain tight spacing and pointing while flying in precision formations, acting as a single research instrument in space, the paper states. Formation flying has been proposed as a means to enhance searches for extraterrestrial planets, enable imaging of black holes with multiple X-ray telescopes on different satellites, and support tests of general relativity through measurements of satellite spacing in a gravitational field. The new LIDAR could enable continuous comparisons and feedback of distances to multiple reference points on multiple satellites. There also may be applications in automated manufacturing, where many parts need to fit together with tight tolerances, according to Nate Newbury, the principal investigator.

NIST’s LIDAR design derives its power from combining the best of two different approaches to absolute distance measurements: the time-of-flight method, which offers a large ambiguity range, and interferometry, which is ultraprecise. The LIDAR relies on a pair of optical frequency combs, tools for precisely measuring different colors (or frequencies) of light. The frequency combs used in the LIDAR are based on ultrafast-pulsed fiber lasers, which are potentially smaller and more portable than typical combs that generate laser light from crystals. The two combs operate at slightly different numbers of pulses per second. Pulses from one comb are reflected from a moving target and a stationary reference plane. The second comb serves as precise timer to measure the delay between the reflections returning from the target and from the reference plane. A computer calculates the distance between the target and the reference plane by multiplying the time delay by the speed of light.

* I. Coddington, W. C. Swann, L. Nenadovic and N. R. Newbury. Rapid, precise absolute distance measurements at long range. Nature Photonics. Published online May 24, 2009.

Laura Ost | Newswise Science News
Further information:
http://www.nist.gov

More articles from Physics and Astronomy:

nachricht Unraveling materials' Berry curvature and Chern numbers from real-time evolution of Bloch states
18.02.2019 | Max-Planck-Institut für Struktur und Dynamik der Materie

nachricht Gravitational waves will settle cosmic conundrum
15.02.2019 | Simons Foundation

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Regensburg physicists watch electron transfer in a single molecule

For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.

The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...

Im Focus: University of Konstanz gains new insights into the recent development of the human immune system

Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens

Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...

Im Focus: Transformation through Light

Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light

When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...

Im Focus: Famous “sandpile model” shown to move like a traveling sand dune

Researchers at IST Austria find new property of important physical model. Results published in PNAS

The so-called Abelian sandpile model has been studied by scientists for more than 30 years to better understand a physical phenomenon called self-organized...

Im Focus: Cryo-force spectroscopy reveals the mechanical properties of DNA components

Physicists from the University of Basel have developed a new method to examine the elasticity and binding properties of DNA molecules on a surface at extremely low temperatures. With a combination of cryo-force spectroscopy and computer simulations, they were able to show that DNA molecules behave like a chain of small coil springs. The researchers reported their findings in Nature Communications.

DNA is not only a popular research topic because it contains the blueprint for life – it can also be used to produce tiny components for technical applications.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Global Legal Hackathon at HAW Hamburg

11.02.2019 | Event News

The world of quantum chemistry meets in Heidelberg

30.01.2019 | Event News

Our digital society in 2040

16.01.2019 | Event News

 
Latest News

The Internet of Things: TU Graz researchers increase the dependability of smart systems

18.02.2019 | Interdisciplinary Research

Laser Processes for Multi-Functional Composites

18.02.2019 | Process Engineering

Scientists Create New Map of Brain’s Immune System

18.02.2019 | Studies and Analyses

VideoLinks
Science & Research
Overview of more VideoLinks >>>