GPS World

Tag: lidar mapping

  • Lidar reveals a hidden Mayan city

    Lidar reveals a hidden Mayan city

    A relief of the ancient Maya site archaeologists are calling Ocomtún. (Image: Žiga Kokalj/ZRC SAZU)
    A relief of the ancient Maya site archaeologists are calling Ocomtún. (Image: Žiga Kokalj/ZRC SAZU)

    In a biological preserve in Mexico’s Campeche State, a team of archaeologists have documented pyramids, palaces, a ball court and other remains of an ancient city they call Ocomtún, reported the New York Times.

    Archeologists surveyed the site for six weeks in May and June, finding  50-foot-tall (15.2-meter-tall) structures resembling pyramids, as well as pottery and Mayan engravings they believe date to between 600 and 900 AD. The team determined the city was likely abandoned more than 1,000 years ago.

    Mexico’s National Institute of Anthropology and History (INAH) hailed their findings late last month, saying they discovered the ancient city in “a vast area practically unknown to archaeology.”

    “I’m often asked why nobody has come there, and I say, ‘Well, probably because you need to be a little nuts to go there,” said Ivan Sprajc, the survey’s lead archaeologist and a professor at a Slovenian research center, ZRC SAZU. “It’s not an easy job.”

    Surveying the area has been revolutionized over the last decade by lidar — allowing researchers to survey densely forested areas that are difficult to explore on foot. Archeologists were able to use airborne lasers to pierce through dense vegetation and reveal the ancient structures and human-modified landscapes beneath.

    INAH described the site as having once been a major center of Mayan life. Surrounded by wetlands, Ocomtún includes pyramids, plazas, elite residences and “strange” complexes of structures arranged almost in concentric circles, Dr. Sprajc told CNN.

    “For example, we have several very curious architecture complexes of structures which are arranged in almost concentric circles. So, we are only guessing what this could be. Perhaps marketplaces,” he added.

    Mexico’s National Institute of Anthropology and History team plans to return next year for further investigation.

  • AEVEX Aerospace: Taming the Wild West

    AEVEX Aerospace: Taming the Wild West

    Lidar point clouds can reveal very fine features, such as electric power lines. Photo: AEVEX Aerospace
    Lidar point clouds can reveal very fine features, such as electric power lines. Photo: AEVEX Aerospace

    We discussed UAV lidar mapping with Bob Stadel, vice president of Geodetics, AEVEX Aerospace.

    What are the key remaining technical challenges in UAV lidar mapping?

    With continuing improvements in UAVs, lidars, GNSS receivers and other sensors, the key to unlocking more efficiency and profitability in this market will be improving and simplifying workflows and processing. The next frontier is integrating AI and machine learning with digital twin models to create forecasting tools.

    UAVs are much cheaper to operate than manned aircraft per hour, but not necessarily per square mile. UAVs can cover ground that cannot be mapped from a land vehicle; however, the latter have a much greater range.

    You are correct. Each type of vehicle has its area of best utilization. Once we know what the customer wants from the data being collected, we can determine the size, weight and power (SWAP) of the payload needed, and then it’s a matter of analyzing cost versus capability and working with the customer to pick the right payload for the right vehicle at the right price.

    What positional accuracy do you achieve for your point clouds?

    With our GNSS-receiver-based navigation unit, which also includes an IMU and key IP [intellectual property] from our company, and the right combination of tools, we achieve an accuracy of 2 cm to 3 cm.

    What are your key markets for UAV lidar mapping?

    I believe it is still the Wild West in this market space. Really smart people are figuring out new ways to use these systems every day. We sell systems to teams doing high-end inspections of infrastructure, such as roads, bridges, corridors and power lines, as well as for land surveying and mining.

    What was a recent application of one of your mapping systems?

    One of our most recent success stories has been the launch of our Geo-ECTO-1 system. It features dual lidar sensors combined with a 360-degree FOV [field of view] camera and high-end GNSS receiver. It is ruggedized from the ground up and is meant for high-end survey and infrastructure inspection work. The payload is designed to quickly transition to a UAV-based system. Our two launch customers/partners are California-based survey companies Guida Survey and LACO Survey. It has been a great experience getting these systems up and running with our partners.

    Our next adventure will be to work with UC San Diego’s Scripps Oceanographic Institute. We are proposing and demonstrating one of these systems to be used for analyzing cliff erosion on the beaches here in California, where several collapses have led to the loss of life. We want to support figuring out how to use the analyses to create a system that would give early warning of trouble spots. With these tools we can make our beaches much safer.

  • Multi-platform lidar enables digital twin cities

    Multi-platform lidar enables digital twin cities

    Digital twin technology emerged a decade ago to provide 3D virtual replicas of physical assets. Today, with Big Data and internet of things (IoT) capabilities, it is a complex and comprehensive method to support the construction of smart cities.

    Mapping Shanghai with the AlphaUni 900. (Image: CHC Navigation)
    Mapping Shanghai with the AlphaUni 900. (Image: CHC Navigation)

    As a virtual model, a digital city can be an indispensable tool to visualize the life of a city in real time. It provides layered data about buildings, urban infrastructure, utilities, businesses, and the movement of people and vehicles. By providing this information, digital twins enable intelligent urban development and modernization.

    Traditional methods of collecting and representing 2D spatial data, such as maps and images, are insufficient to meet the requirements for digital twin city models, where digital data provides the foundation for large-scale projects.

    For example, the derived 3D models must have a high capacity to be merged and correlated with social or economic spatial data from IoT and Big Data. Because of this, a high demand exists for global, accurate, real-time geospatial data that provides high-precision 2D and 3D information.

    Proof-of-concept

    To illustrate a typical digital cities project, CHC Navigation (CHCNAV) carried out a proof-of-concept demonstration in the Jinshan district of Shanghai for one month in March and April.

    The total area of the Jinshan district is approximately 600 km2. This area contains rich terrain features and typical characteristics of large, modern cities, such as high buildings, power lines, rivers and vegetation.

    Extracted 3D mesh created from the data. (Image: CHC Navigation)
    Extracted 3D mesh created from the data. (Image: CHC Navigation)

    The traditional method of capturing with a single-platform lidar system may leave some areas blank in the point-cloud data. CHCNAV’s AlphaUni 900 lidar solution, with its multi-platform capability, was able to capture complete data with four different platforms: an unmanned aerial vehicle (UAV), a car, a backpack and a boat or unmanned surface vehicle (USV).

    The AlphaUni series provides optimized data sets powered by advanced GNSS/inertial navigation system (INS) sensors and long-range scanners.

    Point cloud from aboard an Apache6 USV mapping a water channel. (Image: CHC Navigation)
    Point cloud from aboard an Apache6 USV mapping a water channel. (Image: CHC Navigation)

    During the project, the CHCNAV AlphaUni 900 seamlessly integrated the district’s buildings in the data sets and provided a sophisticated 3D image from both indoor and outdoor environments. Its high-accuracy capability and multi-platform design can improve the way high-precision data is collected. It successfully provides an innovative solution for the problems of 3D geospatial data acquisition required for the development of smart cities.

    Table Data: CHC Navigation
    Table data: CHC Navigation