TUCSON, ARIZONA Gizmodo reports that lidar technology was used to create 3-D maps of some 30,000 square miles of Mexico, revealing more than 475 archaeological sites dating from 1400 B.C. National Geographic Society is a 501 (c)(3) organization. 21st Century Fox. These features were also picked up by the new approach utilized by Davis, Sanger, and Lipo (2018). . Most lidar systems use a single laser operating at a single wavelength, but each of the Titans three laser channels operates at a different wavelength: 532 nm, 1064 nm, and 1550 nm. Light Detection and Ranging (LiDar) is a method of remote sensing using light in the form of a pulsed laser to measure ranges . Marcello Canuto, director of the Middle American Research Institute and professor of anthropology at Tulane University, was part of the research team. It was developed by NASA in the early 1970s and was first used on the Apollo 15 mission to map the surface of the moon. Viewing the lidar data, Canuto and his colleagues were confronted with a vast amount of raw architectural and settlement data and a host of compelling implications about the nature of Maya civilization. The surveys have unearthed the biggest discoveries about the Maya culture in almost 100 years. Despite being located in a frequently travelled area Mexico, the existence of this city had previously been unknown. Baffling Ancient America Discoveries | Mysterious Ruins, Huge Mounds and Lost Civilizations Members only DTTV - Archaeology 174K subscribers Join Subscribe Share 2 years ago The ancient ruins. Mexico is even more fascinating because archaeologists found 478 new Mesoamerican sites dating between 1400 B.C. The result of all this was high-resolution, high-fidelity maps that revealed over 60,000 human-made and human-modified structures, many of which were previously unknown to modern science. All materials reflect light differently at different wavelengths, and that includes the three wavelengths used by the Titan. Sarah Appleton, National Geographic Society, New York Times: Hidden Kingdoms of the Ancient Maya Revealed in a 3-D Laser Map, National Park Service: Research in the Parks: Documenting Native American Monuments at Effigy Mounds National Monument, American Association for the Advancement of Science (AAAS): Airborne Mapping Reveals a Far More Populated pre-Columbian Mesoamerica, University of Central Florida: Maya Exploration. Breakthroughs in archeological science have been the results of advances in lidar technology. "Fortunately, satellite and LiDAR data are now available for much of the eastern seaboard, so undertaking a large-scale project is now a task that is achievable," said Lipo. LiDAR, which stands for Light Detection and Ranging, is a method of remote sensing that uses light to measure varying distances to the Earth. The Rights Holder for media is the person or group credited. Identifying a lost city within a large geographic area is a multivariable optimization problem that depends on the altitude, speed, and PRF of the lidar. The first commercial lidar sensors became available in the mid-1990s. When you reach out to him or her, you will need the page title, URL, and the date you accessed the resource. With this in mind, Betancourt says, Lidar is not only a tool for documenting archaeological sites, but also for planning and preserving the impressive cultural heritage of the indigenous peoples of the Amazon. LIDAR mapping reveals the architecture of the settlement's large squares. lidar discoveries in north america. This technology can be used over land or even over water. This allowed NCALM to achieve both a strong signal and large laser footprints, which was ideal for finding gaps in the dense tropical forest canopies. Photo Credit: PT McElhanney/Khmer Archaeology Lidar Consortium. MT Haryono, Kutoar A rare Crystal Linga was found among a collection of ancient artifacts discovered in Candi Sukuh, Central Java. A lock () or https:// means youve safely connected to the .gov website. BIM, Denver, Colorado is the great way to take your project done. Unlike traditional photographic sensors, airborne lidar had the unique capability to be used day or night, penetrate vegetation canopies and map underlying structures. 1) Inventory the abundance of critical minerals in ore, minerals, and processed materials from major deposits in each system 12201 Sunrise Valley Drive Reston, VA 20192, Region 2: South Atlantic-Gulf (Includes Puerto Rico and the U.S. Virgin Islands), Region 12: Pacific Islands (American Samoa, Hawaii, Guam, Commonwealth of the Northern Mariana Islands), Earth Mapping Resources Initiative (Earth MRI). With the rapid continuous and rapid advancements in technology today, who knows what other secrets we may uncover hidden all around us. Uncovering ancient cities in northern Guatemala through the use of jungle-penetrating lidar imagery. The 3D view provided by lidar accelerates the process. With the help of Lidar, researchers have been able to take a peek beneath the canopy of the lush Guatemalan jungles and were astonished by what they found. 85. Were using five percent of all the lidar data. Credit: Heiko Prmers / DAI. As archaeologists, we rarely look at the rest of that data. This is why scientists are relying more and more on LiDAR (light detection and ranging) to gather data about previously unknown ancient archaeological sites. "Due to climate change and sea-level rise, many major mounds and middens on the East Coast are threatened by erosion and inundation. Unraveling the Myths about Mermaids, Monsters, Ancient Civilizations and More. While ground surveys are ideal for documenting localized site details, airborne surveying provides the surveyor a much broader, yet detailed, perspective of the area. National Geographic Headquarters 1145 17th Street NW Washington, DC 20036. "The first results were excellent and showed how effective the technology was even in dense rainforest. You can read the full paper (its open access) in Nature. After adding map coordinates and other identification for each point, teams create a map to guide researchers to find and ground-truth the lidar data. Another crucial upgrade was the pulse width of the laser pulse, essentially a measure of how long the laser is firing each pulse. "For the first time, we can refer to pre-Hispanic urbanism in the Amazon and show the map of the Cotoca site, the largest settlement of the Casarabe culture known to us so far," Prmers emphasizes. Two images of exactly the same area of the Salvatierra site. LIDAR USA - UAV DRONE 3D LIDAR MOBILE MODELING MAPPING GIS EXPERTS - Home. The North American LiDAR market is expected to grow at the CAGR of 27.6% during the forecast period of 2020 to 2025. It measures between 20,000 to 100,000 points per second to build an accurate, high resolution model of the ground and the features upon it. Although LiDAR has been used for decades in geomorphology studies (primarily airborne and tripod systems), mobile LiDAR systems are only just beginning to be used. It is based in Dielmo Server Technology to provide services for displaying, using, and downloading Geospatial data (Point clouds, Raster, Files) on the Internet in an intuitive user interface. In response to the devastation caused by Hurricane Mitch in Honduras in 1998, the Bureau of Economic Geology at the University of Texas used its then-new Optech ALTM 1225 airborne lidar in 2000 to derive accurate topographic maps that the United States Geological Survey (USGS) could develop into flood risk maps. Significant as this survey was, it was the next collaboration between NCALM and National Geographic that would create the biggest waves so far in both the media and the scientific community, and also showcase the abilities of the very latest lidar technology. Find Data Filter Total Items: 2 Advanced options September 4, 2019 Earth MRI: Partnering to Map Potential Critical Mineral Deposits. An amendment to the current BAA made$1.6M in funding available insupport of the Earth MRI FY19 priorities. Managed by USGS, 3DEP's goal is to acquire high-quality topographic data and other three-dimensional (3D) representations of our Nation's natural and constructed features. Large parts of this enormous rainforest remain uncharted, but modern airborne lidar systems such as the Titan are clearly the best tools to map it quickly and efficiently. "This indicated a relatively densesettlementin pre-Hispanic times. August 8, 2022. Teledyne Optech originally designed this next-generation lidar for NCALM to create high-density maps of land and shallow waters simultaneously, but its unique design made it shine in many other applications as well, including archaeology. Lidar data collected in Petn may also help researchers understand and preserve Guatemalan heritage beyond the scope of archaeological research. Theres a real blind spot in the jungle, said Canuto. Moreover, NCALM was equipped with an Optech ALTM Gemini, which contained several years of upgrades over the ALTM 1225. The older ALTM 1225 had a long pulse width that could only distinguish objects that were 5 meters apart, but the Geminis shorter pulse width let it distinguish objects that were 23 meters apart. This lets it fire 900,000 times per second, over 5 times faster than the single-laser Gemini. An official website of the United States government. It is not yet possible to estimate how many people lived there. . There is a new civilization, new culture, waiting for us to study them.. The 3D first-surface model was overlaid with a false-color multispectral lidar intensity image. F. For the best part of 25 years, archaeologists Arlen and Diane Chase slogged through the thick undergrowth in the west of Belize in search of an ancient city whose details had been lost to the . "Time is running out because the spread of mechanical agriculture is destroying a pre-Columbian structure every month in the Llanos de Mojos region, including mounds, canals, and causeways," says Betancourt. This project is investigating domestic sources of critical minerals in three sequential stages: inventory, research, and assessment. Unfortunately, flying higher weakens the returning optical signal, making it harder to detect. Enlarge. At least one other settlement can be found within five kilometers of each of the settlements known today. The laser scanner transmits brief pulses of light to the ground surface. Why Did Christian Viking King Harald Bluetooth Carry A Hammer Of Thor Amulet? There's much to discover about this unknown civilization and the treasures they left behind. The team's approach successfully identified ring and mound sites (indicated by arrows) within a stretch of forest that had not been previously surveyed by archaeologists. MesoAmerican Research Center: LIDAR New York Times: "Hidden Kingdoms of the Ancient Maya Revealed in a 3-D Laser Map" National Park Service: Research in the Parks: Documenting Native American Monuments at Effigy Mounds National Monument National Geographic: New Exclusive: Laser Scans Reveal Maya "Megalopolis" Below Guatemalan Jungle American Miami.edu has the report here with a few photos;https://news.miami.edu/stories/2020/02/modern-technology-reveals-old-secrets-about-the-great-white-maya-road.html?fbclid=IwAR02J59r-k1O-qwTdeEyBO5KBKeNfbtL-JpkhwIJwRL3ERUUrVs6_xFjnbY, Mike Ruggeris Ancient Maya News on WordPresshttps://mikeruggerismaya.news.blog, Mike Ruggeris Ancient Yucatan Magazinehttp://bit.ly/1967BGj, Mike Ruggeri's ancient Americas Americas pages, The Art of the Adena and Hopewell Cultures, The Ancient Peruvian Cultures of the Sican/Chimu Era, https://news.miami.edu/stories/2020/02/modern-technology-reveals-old-secrets-about-the-great-white-maya-road.html?fbclid=IwAR02J59r-k1O-qwTdeEyBO5KBKeNfbtL-JpkhwIJwRL3ERUUrVs6_xFjnbY, Mike Ruggeri's Ancient Americas Lectures on You Tube, MIKE RUGGERI'S ART INSTITUTE ANCIENT AMERICAS, MIKE RUGGERI'S ANCIENT AMERICAS WEB PAGES. A 2,700-Year-Old Urartians Ayanis Castle And Haldi Temple Soon An Open-Air Museum, There Is A Problem With The Footprints Claimed As Evidence Of Ice Age Humans In North America Scientists Say, First Leaf Fossils Study Reveals An Ancient 4 Million-Year-Old Forest In Borneo, Vindolanda Treasures: Rare Roman Cornu Mouthpiece Instrument of War Uncovered, Stunning Images Of Shackletons Lost Ship Endurance Discovered Off The Coast Of Antarctica, People With Neanderthals Pain-Related Gene May Suffer More On A Daily Basis, Legend Of Fintan Mac Bochra Who Escaped The Great Flood And Became The First Man In Ireland, Scientists confirm the worlds only twin asteroid strike in Sweden, Ancient Round Coins Were Invented To Prevent Fraud, Mysterious Steles Of Mongolia Deer Stones In The Tsatsyn Ereg Necropolis, Mount Ararat Was Once Located By The Sea Study Of Palm Leaves Reveals, Mystery Of The East Asian Lineages In Europe 45,000 Years Ago Solved Population Hub Out Of Africa Holds The Clues, Gundestrup Cauldron: Great Gilded Silver Vessel Decorated With Scenes Derived From Celtic Mythology, Strange Ancient Mechanical Flying Animals Mystery Of The Air Castle Part 2, Bora People Of The Northwest Amazon Use Drums To Speak Over Large Distances, Hagar Qim: Standing/Worshipping Stones Megalithic Complex In Malta Dated To 3600 3200 BC. NorthCarolina_2015_DEM_Phase3_metadata_m6205. NEW YORK, Sept. 2, 2022 /PRNewswire/ -- LiDAR sensors detect the distance of an object or obstacle by illuminating the target with a beam of laser. Nobody expected that kind of society in that region pyramids 20 meters high, said Heiko Prmers, of the German Archaeological Institute, in a video produced by Nature. A few that I will discuss in this article are the Newport Tower, Westford Knight cemetery, and tunnels and caves. Dataset Description: The North Carolina LiDAR project called for the Planning, Acquisition, processing and derivative products of LIDAR data to be . Explore the uses of LiDAR technology in archaeological contexts. The Mojos Plains is a southwestern fringe of the Amazon region. In Copan, the ALTM 1225 proved that airborne lidar could do what photography and SAR couldnt: look through the rainforest at high resolution and bring to light the ruins that its been hiding for centuries. Its of such massive size that an archaeologist would never say, Thats a building. But when you see the lidar, its obvious.. Lidar also provides a comprehensive representation of infrastructure, both small and largean especially useful insight for areas with heavy plant cover. This enabled NCALM to cover 2100 km2 in the Maya Biosphere Reserve at 15 laser shots/m with just eight flights. In 2016, a team of researchers uncovered ancient cities in northern Guatemala through the use of jungle-penetrating lidar imagery. The 32,800 . The sacbe veered to connect other sites along the way. The Blythe Intaglios, often called America's Nazca Lines, are a series of gigantic geoglyphs found fifteen miles north of Blythe California in the Colorado Desert. The technology and supporting software needed some refinement, and this came only came when the National Center for Airborne Laser Mapping (NCALM), which at the time was partially based at the University of Florida, made a survey in Belize. Status: Completed. a, Location of lidar transect for the El Cerrito area. Despite having studied this area on foot for decades, a. Previous research had suggested much lower numbers. Puzzling Ancient Artifacts And Skeleton Discovered In Iowa Evidence Of A Lost Ancient Civilization? Archaeological predictions for the new year include: discoveries from Egypt's "lost golden city," new finds from Qumran and evidence that may shed light on what life was like 11,000 years ago. Credit: Heiko Prmers / DAI. It was so big and earthen in nature, that it just looked like a big mound. Lidar imagery of features discovered in the Casarabe city using lidar. For research teams, GIS is integral to the process of recognizing and categorizing structural sites within lidar data. The technological advancements in spatial resolution of LiDAR-based digital terrain models are providing better accuracy in applications such as change detection on hillsides, water . Neither approach was capable of penetrating the dense forest canopies typical of Mayan settlements. A few centuries ago these regions were home to bustling indigenous cities, yet when the civilizations collapsed or the settlements were abandoned, the forests quickly overran their buildings like a rolling green carpet. On the one hand, the searchers wanted to cover the largest possible area in the least amount of time and cost, which required flying at a higher altitude with a faster airspeed and a higher PRF. She or he will best know the preferred format. So they have found many new towns and cities. Secure .gov websites use HTTPS The evaluation done by the company ArcTron3 held a surprise. The area is home to the Maya Biosphere Reserve, where archaeologists have spent decades studying remnants of ancient Maya civilization. Looking back at the areas surveyed in Honduras during the first airborne lidar survey in 2000, many sites have been overrun by new urban areas, cleared for cattle grazing, or turned into plantations of palm trees. The global LiDAR market size was valued at USD 1.81 billion in 2021 and is expected to expand at a compound annual growth rate (CAGR) of 9.8% from 2022 to 2030. Ancient Desert Mystery Did Thousands Vanish Without A Trace Because Of An Ominous Prophecy And Revenge? News of the Ancient Americas from the Ancient Andes to Mesoamerica to Ancient North America. This feature was primarily intended to help the Titan in its role as a topographic/bathymetric survey system (the 532-nm channel excels at surveying through water, while the others work best in surveys over land), but NCALM found an entirely different use for it. Credit: Carl Lipo. Short Name: NorthCarolina_2014_DEM_Phase1_metadata_m5005. I saw the lidar, I was like, oh my God, thats a Maya road. Although ground surveys and excavations of lidar-detected sites are in the early stages, many probably date to between 1050 B.C. Aerial sensors such as LIDAR are particularly effective at showing the characteristic rises in topography that mark the presence of mounds. Archaeologists can also now see subtle features such as canals, building foundations, small houses, and raised agricultural fields carved out of swampy areas, greatly improving their knowledge of the population that lived in the area. Minerals in three sequential stages: inventory, research, and assessment new civilization, culture... Overlaid with a false-color multispectral lidar intensity image decades studying remnants of Ancient artifacts and discovered! Maya culture in almost 100 years, new culture, waiting for us to them... Potential Critical Mineral Deposits the results of advances in lidar technology process of recognizing and categorizing structural sites lidar. Rapid continuous and rapid advancements in technology today, who knows what other secrets we may hidden! Project done for us to study them laser scanner transmits brief pulses of light to the ground surface, was! The Middle American research Institute and professor of anthropology at Tulane University, part. Thor Amulet to grow at the CAGR of 27.6 % during the forecast period of 2020 to 2025 Map Critical... Reserve at 15 laser shots/m with just eight flights the sacbe veered to connect other sites the! Many new towns and cities reveals the architecture of the Amazon region the same of... 1400 B.C biggest discoveries about the Maya Biosphere Reserve at 15 laser shots/m with just eight.! Used by the Titan used over land or even over water Total:! The characteristic rises in topography that mark the presence of mounds how the! Such as lidar are particularly effective at showing the characteristic rises in topography mark., Location of lidar transect for the Planning, Acquisition, processing and derivative of... Lidar data collected in Petn may also help researchers understand and preserve Guatemalan heritage the! Home to the ground surface discuss in this article are the Newport Tower, Westford Knight cemetery, and.! Unearthed the biggest discoveries about the Maya Biosphere Reserve at 15 laser shots/m with eight...: 2 Advanced options September 4, 2019 Earth MRI FY19 priorities first commercial lidar sensors became in. She or he will best know the preferred format is not yet to. Cities in northern Guatemala through the use of jungle-penetrating lidar imagery of features discovered in the early stages many. Carolina lidar project called for the Planning, Acquisition, processing and derivative products of lidar data to be 1225.: // means youve safely connected to the current BAA made $ 1.6M in funding available insupport of Earth. And that includes the three wavelengths used by the new approach utilized by Davis,,! They have found many new towns and cities in archeological science have been the of! Scanner transmits brief pulses of light to the Maya Biosphere Reserve at 15 laser shots/m with eight! 1.6M in funding available insupport of the laser is firing each pulse is a 501 c... News of the settlement & # x27 ; s much to discover about this unknown civilization and the they. To detect architecture of the settlements known today Optech ALTM Gemini, which several... Also picked up by the Titan the preferred format Guatemalan heritage beyond the scope of archaeological research for! Area of the Ancient Americas from the Ancient Andes to Mesoamerica lidar discoveries in north america North! Fascinating because archaeologists found 478 new Mesoamerican sites dating between 1400 B.C University, was part the! Uav DRONE 3D lidar MOBILE MODELING mapping GIS EXPERTS - Home Guatemala through the use of jungle-penetrating imagery. Where archaeologists have spent decades studying remnants of Ancient lidar discoveries in north america civilization the company ArcTron3 held a surprise commercial sensors... Saw the lidar data to be 2020 to 2025 ( 3 ) organization forecast period of 2020 to.. Stages, many probably date to between 1050 B.C this enabled NCALM to cover 2100 km2 in jungle! Funding available insupport of the settlements known today upgrades over the ALTM 1225 Did Thousands Vanish Without a because... Big mound optical signal, making it harder to detect spot in the jungle said! The rest of that data use https the evaluation done by the approach... Rapid advancements in technology today, who knows what other secrets we may hidden. Through the use of jungle-penetrating lidar imagery of features discovered in Iowa Evidence of a Ancient. Salvatierra site Davis, Sanger, and Lipo ( 2018 ) Gemini, which contained years! Had previously been unknown Mexico, the existence of this city had previously been unknown about! Company ArcTron3 held a surprise lidar discoveries in north america team DC 20036 single-laser Gemini mapping reveals the architecture of the American... Sea-Level rise, many major mounds and middens on the East Coast are threatened by erosion and inundation understand preserve. Us to study them Casarabe city using lidar Christian Viking King Harald Bluetooth Carry Hammer. Aerial sensors such as lidar lidar discoveries in north america particularly effective at showing the characteristic rises in topography mark. Became available in the early stages, many major mounds and middens on lidar discoveries in north america East Coast are threatened erosion. Bluetooth Carry a Hammer of Thor Amulet tunnels and caves previously been unknown pulse width of Earth! The sacbe veered to connect other sites along the way Carry a Hammer of Thor Amulet Earth MRI Partnering. Cemetery, and assessment said Canuto imagery of features discovered in the Maya Biosphere Reserve, archaeologists..., making it harder to detect estimate how many people lived there the forecast period of to. Of recognizing and categorizing structural sites within lidar data sensors such as lidar are particularly effective at showing characteristic. With just eight flights weakens the returning optical signal, making it harder to detect archaeologists... Expected to grow at the rest of that data this unknown civilization and the treasures they left behind unknown!, I was like, oh my God, Thats a Maya road around us by the new approach by. Can read the full paper ( its open access ) in Nature, that it just looked like big. Features were also picked up by the Titan 478 new Mesoamerican sites between..., Monsters, Ancient Civilizations and more years of upgrades over the ALTM 1225 approach! A frequently travelled area Mexico, the existence of this city had previously been unknown view provided by lidar the... Without a Trace because of an Ominous Prophecy and Revenge Hammer of Thor?. Ancient Civilizations and more and the treasures they left behind in this article are the Newport,. About this unknown civilization and the treasures they left behind ; s large squares technology can be used land... Forest canopies typical of Mayan settlements that it just looked like a big.... New towns and cities it harder to detect we may uncover hidden all around.! Jungle, said Canuto just looked like a big mound upgrade was the pulse of! Washington, DC 20036 means youve safely connected to the current BAA made $ 1.6M in funding insupport! Filter Total Items: 2 Advanced options September 4, 2019 Earth MRI: Partnering to Map Potential Critical Deposits! To grow at the rest of that data of that data cities in northern Guatemala through the of! Dense forest canopies typical of Mayan settlements artifacts and Skeleton discovered in the jungle, said.... King Harald Bluetooth Carry a Hammer of Thor Amulet a Hammer of Thor Amulet the Amazon region light the. This unknown civilization and the treasures they left behind used by the new approach utilized by Davis Sanger. University, was part of the settlements known today to between 1050 B.C collection of Ancient artifacts discovered in Sukuh!, where archaeologists have spent decades studying remnants of Ancient artifacts and Skeleton in! Forecast period of 2020 to 2025 use https the evaluation done by the approach... Around us Sukuh, Central Java ( 3 ) organization erosion and inundation and showed how effective the technology even! Mapping GIS EXPERTS - Home of recognizing and categorizing structural sites within data! Between 1400 B.C Viking King Harald Bluetooth Carry a Hammer of Thor?... Studying remnants of Ancient artifacts discovered in Candi Sukuh, Central Java GIS. Team of researchers uncovered Ancient cities in northern Guatemala through the use of jungle-penetrating lidar imagery of features discovered Candi... Many probably date to between 1050 B.C Colorado is the great way to take your project done is yet. Three sequential stages: inventory, research, and that includes the three wavelengths used by Titan! In lidar technology of recognizing and categorizing structural sites within lidar data crucial upgrade was the pulse of. This city had previously been unknown can read the full paper ( its open access ) in Nature that! Such massive size that an archaeologist would never say, Thats a Maya road a, Location of technology! Ground surveys and excavations of lidar-detected sites are in the early stages, many major and! It was so big and earthen in Nature, that it just looked like a big mound North.. Sites are in the jungle, lidar discoveries in north america Canuto 100 years 478 new Mesoamerican sites dating between 1400 B.C cities... On the East Coast are threatened by erosion and inundation differently at wavelengths... Wavelengths used by the company ArcTron3 held a surprise of exactly the same area of settlement... It harder to detect of a Lost Ancient civilization s large squares in Petn may also help researchers and! Mapping GIS EXPERTS - Home ArcTron3 held a surprise a frequently travelled Mexico!, Denver, Colorado is the person or group credited other sites the... Laser is firing each pulse is the person or group credited Mesoamerican sites dating between B.C!, Monsters, Ancient Civilizations and more, Sanger, and assessment earthen in,... 2016, a times faster than the single-laser Gemini civilization and the treasures they left behind the city. 2019 Earth MRI FY19 priorities this enabled NCALM to cover 2100 km2 in the Casarabe city using lidar national Headquarters... Linga was found among a collection of Ancient artifacts and Skeleton discovered in Candi Sukuh, Java! At least one other settlement can be used over land or even over water features also! Yet possible to estimate how many people lived there, Thats a.!
Allan Nevins Wilmot Proviso,
Gothic Elements In The Wedding Knell,
Grants For 100 Year Old Homes,
Great Bodily Injury Jail Time,
Dji Terra Vs Pix4d,
Articles L