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Lidar: 3D Laser Scanning; Odd Light Phenomena Observed

EnolaGaia

EnolaGaia

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This thread is being assembled to contain posts relating to Lidar / LIDAR ranging technologies used to efficiently scan 3D objects and surfaces:
Lidar (also LIDAR, or LiDAR; sometimes LADAR) is a method for determining ranges (variable distance) by targeting an object with a laser and measuring the time for the reflected light to return to the receiver. Lidar can also be used to make digital 3-D representations of areas on the earth's surface and ocean bottom, due to differences in laser return times, and by varying laser wavelengths. It has terrestrial, airborne, and mobile applications.
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https://en.wikipedia.org/wiki/Lidar

The Fortean aspects of Lidar usage include (e.g.) detection of ancient sites and works not readily visible at ground level and causing odd phenomena that are easily misinterpreted as anomalous beams of light.
 
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Neolithic horned cairns near Caithness wind farm scanned

A wind farm developer has paid for archaeologists to scan a cluster of seven Neolithic horned cairns near to where 21 turbines will be erected.

The 5,000 year old structures at Hill of Shebster, near Thurso, in Caithness, were used for burials and rituals.

Light Detection and Ranging (LiDAR) equipment was used to map the cairns.

Edinburgh-based AOC Archaeology also recorded 300 new Bronze and Iron Age sites in the £100,000 project funded by Baillie Wind Farm.

The new sites included hut circle settlements.

Archaeologists have produced three-dimensional images of the horned cairns from the scans.

The stone structures are more than 60m (196ft) in length and have two projecting walls at their entrances that create small courtyard areas.

A car park and path are to be built near the cairns to allow the public to visit them.

Consultant Dr Graeme Cavers, of AOC Archaeology, said: "The Shebster area is an unusually good example of a well-preserved cluster of sites.

"They are essentially burial and ritual monuments, much like the chapels and shrines of more recent times, and each of them is likely to have been used exclusively by individual local groups or communities."

He added: "The survey makes an invaluable contribution to the archaeological record of Caithness, and is really the first large-scale survey of its kind undertaken in Scotland."
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http://www.bbc.co.uk/news/uk-scotland-h ... s-17463275
 
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Lidar was the key to discovering the legendary lost city of Ciudad Blanca in Honduras.

Legendary Lost City of Ciudad Blanca May Have Been Found With Airborne LiDAR
http://www.sciencedaily.com/releases/20 ... 092719.htm

A field team from the University of Houston and the National Science Foundation (NSF) National Center for Airborne Laser Mapping (NCALM) has mapped a remote region of Honduras that may contain the legendary lost city of Ciudad Blanca. (Credit: DAR)

ScienceDaily (June 6, 2012) — A field team from the University of Houston and the National Science Foundation (NSF) National Center for Airborne Laser Mapping (NCALM) has mapped a remote region of Honduras that may contain the legendary lost city of Ciudad Blanca.

The results, recently announced by Honduras President Porfirio Lobo, mark the successful completion of the first light detection and ranging (LiDAR) survey of that country's Mosquitia region, one of the world's least-explored virgin rainforests.

An initial analysis of the LiDAR survey has identified ruins that could be those of Ciudad Blanca or other long-hidden sites. The information provides archaeologists with the precise locations of features within fractions of meters for further study.

UH serves as the operational center for NCALM, a collaborative program between UH and the University of California at Berkeley. NCALM focuses on the collection of research quality, airborne LiDAR data for NSF principal investigators, the advancement of airborne LiDAR technology and applications and the education of students to fill positions in academic, government and commercial organizations requiring knowledge of airborne LiDAR.

The NCALM Operational Center's experience in completing more than 150 projects across the nation was critical to the successful completion of the Honduras mapping project, which was initiated by UTL Scientific LLC., a group formed by principals of the Honduran LiDAR survey project.

UTL project leader Steve Elkins has been fascinated with the Mosquitia rainforest since his first visit there nearly 20 years ago, but he has been frustrated by the inability of satellite imagery to see under the extremely thick canopy. He contacted researchers at UH, NCALM and Geosensing Systems Engineering (GSE) Graduate Research Program to overcome this obstacle.

UH professors Ramesh L. Shrestha and William E. Carter have been working with refining and applying airborne LiDAR to unveil the surface of Earth, primarily for earth scientists researching surface processes, for more than a decade.

In 2009, the UH researchers and a field team composed of Michael Sartori, Juan Fernandez?Diaz and Abhinav Singhania successfully mapped the Caracol archaeological site in Belize using airborne LiDAR. Even though the site was covered with dense rainforest, the LiDAR data captured building ruins and agricultural terraces not discovered by archaeologists working on the ground for more than 25 years.

In the Honduras project, the UH team blanketed the area with as many 25 to 50 laser pulses per square meter -- a total of more than four billion laser shots. A number of areas were mapped and the images collected were reduced and filtered to remove the vegetation and provide "bare earth" digital elevation models in near real?time in the field.

The digital elevation models were then used to produce geodetic images of the terrain's surface below the rainforest, and those images were searched by eye to study geomorphological features as well as potential archaeological ruins.

The project has demonstrated the power of airborne laser mapping to locate archaeological ruins in regions covered with thick forest, and it appears that the method will be used widely in the years ahead.

Story Source:

The above story is reprinted from materials provided by University of Houston.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.
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http://www.sciencedaily.com/releases/20 ... 092719.htm
 
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Avoids the danger of giant snakes, angry tribes etc.

Drones map ancient Peruvian ruins
21:45 3 August 2012
Hal Hodson, technology reporter

For the past month, a lunch tray-sized aircraft has been skimming over Peruvian ruins snapping high-definition photos which are then stitched together to build a 3D map of the site. ...

Although the drone will be mapping the site in 3D to a level of detail which Wenke says is better than "even the best satellite imagery", it won't be mapping the interior of the ruins.

To that end, Nadir Bagaveyev, a design engineer at XCOR Aerospace in Mojave, California recently completed a successful Kickstarter campaign to raise funds to build a cheap laser radar (LiDAR) capable of being integrated into any robotics project and returning reliable three dimensional spatial coordinates.

More expensive LiDARs work by measuring the length of time it takes a laser signal to complete a round trip between the point of measurement and surrounding features, calculating distances by multiplying the measured time by the speed of light. Bagaveyev is planning to make his system cheaper by doing away with the high precision timing equipment, and instead measuring the angles and distances between laser spots that reflect off the drone's surroundings, calculating a distance using trigonometry.
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newscientist.com/blogs/onepe ... an-ru.html
Link is dead. The MIA webpage (quoted in full above) can be accessed via the Wayback Machine:
https://web.archive.org/web/2012080...t/2012/08/drones-map-ancient-peruvian-ru.html
 
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Beyond Angkor: How lasers revealed a lost city
By Ben Lawrie, Documentary film-maker

Deep in the Cambodian jungle lie the remains of a vast medieval city. Hidden for centuries, new archaeological techniques are now revealing its secrets - including an elaborate network of temples and boulevards, and sophisticated engineering. ...

Today Cambodia is famous for these buildings. The largest, Angkor Wat, constructed around 1150, remains the biggest religious complex on Earth, covering an area four times larger than Vatican City. It attracts two million tourists a year and takes pride of place on Cambodia's flag.

But back in the 1860s Angkor Wat was virtually unheard of beyond local monks and villagers. The notion that this great temple was once surrounded by a city of nearly a million people was entirely unknown.

It took over a century of gruelling archaeological fieldwork to fill in the map. The lost city of Angkor slowly began to reappear, street by street. But even then significant blanks remained.

Then, last year, archaeologists announced a series of new discoveries - about Angkor, and an even older city hidden deep in the jungle beyond.
An international team, led by the University of Sydney's Dr Damian Evans, had mapped 370 sq km around Angkor in unprecedented detail - no mean feat given the density of the jungle and the prevalence of landmines from Cambodia's civil war. Yet the entire survey took less than two weeks.

Their secret?
Lidar - a sophisticated remote sensing technology that is revolutionising archaeology, especially in the tropics.
Mounted on a helicopter criss-crossing the countryside, the team's lidar device fired a million laser beams every four seconds through the jungle canopy, recording minute variations in ground surface topography.
The findings were staggering.

The archaeologists found undocumented cityscapes etched on to the forest floor, with temples, highways and elaborate waterways spreading across the landscape.

"You have this kind of sudden eureka moment where you bring the data up on screen the first time and there it is - this ancient city very clearly in front of you," says Dr Evans.

These new discoveries have profoundly transformed our understanding of Angkor, the greatest medieval city on Earth.
At its peak, in the late 12th Century, Angkor was a bustling metropolis covering 1,000 sq km. (It would be another 700 years before London reached a similar size.) ...

But its origins and birthplace were shrouded in mystery.

A few meagre inscriptions suggested the empire was founded in the early 9th Century by a great king, Jayavarman II, and his original capital, Mahendraparvata, was somewhere in the Kulen hills, a forested plateau north-east of the site on which Angkor would later be built.

But no-one knew for sure - until the lidar team arrived.

The lidar survey of the hills revealed ghostly outlines on the forest floor of unknown temples and an elaborate and utterly unexpected grid of ceremonial boulevards, dykes and man-made ponds - a lost city, found. ...
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http://www.bbc.co.uk/news/magazine-29245289
 
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I've been using this as wall paper for some time - LIDAR.


UK_Stonehenge_02.jpg
 
Wow! There's so much 'ritual' stuff there!
 
Not a philosophical experiment on the nature of velocity but still puzzling... tonight around 20:30 hours while walking home through Carnoustie in Scotland a train went hurtling past with an intense beam of violet light shining out of its roof, bright enough to light up the quite low level clouds as it passed. I cant find any reference to the phenomena anywhere does anyone out there have any knowledge of it?
 
This incident appears to have had masses of witnesses.

What about a misaligned anti-leaf laser system? They are being tested eg in the Netherlands (perhaps also in Angus? I'd never considered lasers being used in Aberdeenshire or Angus, but maybe the time is ripe....)
link_qDrybttdKgNp2dWfcTkikT2iKmYeQkQu,w1200h627.jpg
 
Ermintruder said:
This incident appears to have had masses of witnesses.

What about a misaligned anti-leaf laser system? They are being tested eg in the Netherlands (perhaps also in Angus? I'd never considered lasers being used in Aberdeenshire or Angus, but maybe the time is ripe....)
link_qDrybttdKgNp2dWfcTkikT2iKmYeQkQu,w1200h627.jpg
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That would only work if it was the right kind of leaves on the track :)
 
Another description. Makes me wonder if it was someone playing around with a high powered spotlight
Lindsay RockIt was a normal train it past us as we waited to cross the carriageway into fourdon. There was 2 beams coming from a carridge could see it perfectly coming out of the window. The beams were very high and large coming out of the window. No idea why. Was freaky as it started moving towards us as we seen it for a good while till it passed us.
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https://www.facebook.com/FubarNews/
 
Gordon Cameron said:
Not a philosophical experiment on the nature of velocity but still puzzling... tonight around 20:30 hours while walking home through Carnoustie in Scotland a train went hurtling past with an intense beam of violet light shining out of its roof, bright enough to light up the quite low level clouds as it passed. I cant find any reference to the phenomena anywhere does anyone out there have any knowledge of it?
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I can answer this one as this is my field of employment and I live locally! You saw the Network Rail New Measurement Train which, as the name suggests, carries out all sorts of measurements and tests to check the condition of the railway infrastructure. The light is part of the Plain Line Pattern Recognition (PLPR) system which uses LIDAR technology and a very, very, very high speed camera to automatically check for damaged or missing components in the track to a very high level of accuracy and also surveys dynamic clearances to fixed structures around the railway - hence the lights on the roof and below the solebar. The data it collects is used to check for track faults and plan maintenance work. The NMT is one of several different Infrastructure Monitoring trains which run round the network - it carries out a cyclic pattern of inspections and passes through Carnoustie every 8 weeks on a run from Heaton (Newcastle) to Aberdeen and return. I've been on it a couple if times, it's very interesting to see in action.

Further information - https://en.wikipedia.org/wiki/New_Measurement_Train

https://www.theregister.co.uk/2014/11/10/network_rail_new_measurement_train_ride/
 
Carse said:
I can answer this one as this is my field of employment and I live locally! You saw the Network Rail New Measurement Train which, as the name suggests, carries out all sorts of measurements and tests to check the condition of the railway infrastructure. The light is part of the Plain Line Pattern Recognition (PLPR) system which uses LIDAR technology and a very, very, very high speed camera to automatically check for damaged or missing components in the track to a very high level of accuracy and also surveys dynamic clearances to fixed structures around the railway - hence the lights on the roof and below the solebar. The data it collects is used to check for track faults and plan maintenance work. The NMT is one of several different Infrastructure Monitoring trains which run round the network - it carries out a cyclic pattern of inspections and passes through Carnoustie every 8 weeks on a run from Heaton (Newcastle) to Aberdeen and return. I've been on it a couple if times, it's very interesting to see in action.

Further information - https://en.wikipedia.org/wiki/New_Measurement_Train

https://www.theregister.co.uk/2014/11/10/network_rail_new_measurement_train_ride/
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I've seen council trucks using this light emission scanning device to detect road faults and flatness/bumps. They never bloody fix anything, but it was interesting to be driving behind them while they had the scanner going. Seen it on at least two occasions.
 
A new remote sensing (LIDAR) survey has identified a large number of previously undocumented Mayan structures in northern Guatemala.

Thousands of Mysterious Maya Structures Discovered in Guatemala
An aerial survey over northern Guatemala has turned up over 60,000 new Maya structures, including pyramids, causeways, house foundations and defensive fortifications.

It's a watershed discovery that has already led archaeologists to new sites to excavate and explore. The findings may also revise estimates of how many ancient Maya once lived in the region upward by "multiple factors," said Tom Garrison, an archaeologist who specializes in the Maya culture and is part of the consortium that funded and organized the survey. Far more ancient Maya lived on the landscape than there are people in the region today, Garrison told Live Science, and they did it without the destructive slash-and-burn agriculture that is crippling the jungle in modern times. ...
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FULL STORY: https://www.livescience.com/61616-mysterious-maya-structures-discovered.html

Associated Slide Show: https://www.livescience.com/61618-maya-civilization-photos.html
 
Bronze Age monument discovered in Forest of Dean
A previously unknown Bronze Age monument has been discovered hidden in woodland in the Forest of Dean following an airborne laser scan.
The ritual monument, known as a ring cairn, dates back to about 2,000 BC.
It consists of a circular bank with several small limestone standing stones on top.
Archaeologist Jon Hoyle, who found it, said it was the only site of its kind known about in Gloucestershire, and was a "very significant" discovery
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(C)BBC. '19
 
How a public map helped an archaeologist to discover ancient Mayan ruins

Until recently, archaeology was limited by what a researcher could see while standing on the ground. But light detection and ranging, or lidar, technology has transformed the field, providing a way to scan entire regions for archaeological sites.

With an array of airborne lasers, researchers can peer down through dense forest canopies or pick out the shapes of ancient buildings to discover and map ancient sites across thousands of square miles. A process that once required decades-long mapping expeditions, and slogging through jungles with surveying equipment, can now be done in a matter of days from the relative comfort of an aeroplane.
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(C) The Independent. '19
 
Newly published results from LIDAR surveys in southwestern Amazonia demonstrate a surprising number of ancient villages with mounds and interconnecting roads.
Archaeologists Discover Hidden Network of Amazonian Villages Arranged Like Clock Faces

Using remote laser scanners mounted on helicopters, archaeologists have been able to peer below the forest canopy of the Amazon, revealing the layouts and links of ancient villages laid out like clock faces.

While these so-called mound villages had been spotted before, the new surveying technology has revealed exactly how they were organised at scale, and the data were gathered without the need for laborious work and excavation on the ground. ...

"LIDAR has allowed us to detect these villages, and their features such as roads, which wasn't possible before because most are not visible within the best satellite data available," says archaeologist José Iriarte, from the University of Exeter in the UK. ...

The scans showed how the villages – built between 1300-1700 CE – were arranged to represent very specific social models, with no clear hierarchy.

"The uniform spatial layout of the mound villages, like many contemporaneous ring villages of the Neotropics, are likely to represent physical representations of the Native American cosmos," the team writes in their paper.

Between 3 and 32 mounds were found at each site, with the mounds themselves as high as 3 metres (9.8 feet) in some cases, and stretching up to 20 metres (65.6 feet) in length. Closer investigation in the future should be able to reveal exactly what these mounds were used for – from houses to cemeteries.

Long, sunken minor and major roads with high banks were also discovered by LIDAR, radiating from the mound villages like rays of sunshine or the hands of a clock. Most villages showed two roads leaving to the north, and two to the south. ...

The research has been published in the Journal of Computer Applications in Archaeology.
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FULL STORY: https://www.sciencealert.com/lidar-...-amazonian-villages-arranged-like-clock-faces
 
If you're at the California coast at night and notice a triangular set of lights flying overhead and beaming down a weird green light - don't panic. It's not a UFO; it's an aircraft using Lidar to map the coastline and coastal waters.
Scanned By A Laser Beam From The Sky In California Recently? Here's What Did It

The green laser shooting down from the sky may look like a scene out of Stranger Things, but it has a very down-to-earth purpose.

It was a scene right out of a sci-fi thriller: a broad beam of green light emanating from an aircraft overhead scanning across the ground in the darkness. Videos like the one below have been shared on social media, showing the eerie and — for many — outright puzzling scene along the Southern California coast.

The flight left people perplexed, but what was happening is entirely explainable. The aircraft in question was equipped with an advanced lidar system operated by Woolpert, an engineering consulting firm, in support of the National Coastal Mapping Program of the U.S. Army Corps of Engineers (USACE). ...

Referred to as a bathymetric scan, the purpose of flights like this is to map coastal waters in high resolution. Lidar, short for “light detection and ranging,” uses lasers to precisely measure distances from a receiver. Though the uncanny experience of being scanned from above may be unnerving, the lasers are safe for eyes given the altitude of the plane and the brevity of the exposure.

Residents of California’s coasts may be noticing the flights for some time. The mapping process, while highly precise, requires extensive airtime. A 2015 survey in California required more than 1,000 flight lines flown over 90 days ... Observers in the area of the current survey will likely notice Woolpert’s King Air 300 Turboprop making repeated passes as part of the data collection process. Some of the flights are being conducted at night to avoid interfering with the region’s heavy air traffic. ...
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FULL STORY: https://www.thedrive.com/the-war-zo...-sky-in-california-recently-heres-what-did-it
 
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