Demystifying Spatial Digital Twins

Geospatial data captured by surveyors will unlock more applications in smart cities, infrastructure, utilities and smart agriculture, helping to connect the digital and physical worlds

Despite rocketing to buzzword status in the geospatial realm, the digital twin is not a new idea. In fact, the idea was first developed by NASA in the 1960s to help save the Apollo 13 crew by duplicating processes in the digital environment to then deploy in the real world. 

But much has changed since those early days. A digital twin is still a virtual environment that represents real space. However, the concept takes on new life with technological advances, mass data collection capabilities from real-time sensors and artificial intelligence (AI) and machine learning. In particular, the evolution of the internet of things (IoT) is helping transform digital twins into “living” (and adapting) digital environments with important uses in the real world, such as production line analysis and smart city simulations to solve urban challenges. When supported by connected sensors, digital twins can even become intelligent reflections of physical things in motion, duplicating physical orientation, shape, position, gesture or motion.

Sophisticated digital twins have also begun to use AI and machine learning algorithms for predictive learning. For instance, one of the possible uses of a digital twin is to virtually track the real-time movement of materials through a supply chain with help from IoT sensors. With AI and machine learning, that same system can now support process improvements.

Emerging Applications

For some time, the digital twin space has been dominated by manufacturing, and more recently healthcare and pharmaceutical applications, but hype within the construction industry is at an all-time high. 

According to Mordor Intelligence, the digital twin market was valued at $10.27 billion in 2021, and it is expected to reach a value of $61.45 billion by 2027, registering a CAGR of 34.48% over the forecast period, 2022-2027. According to the report, while manufacturing has begun to embrace digital twin technology, construction has remained largely a 2D industry and one that hungers for technological innovation. With digital twins, off-site experts now have access to on-site views to verify current project progress, respond to issues and avoid costly rework.

Further, the report authors noted, it has been expected that increased demand for digital twins by owners and operators of buildings and infrastructure will create new market opportunities for digital technologies and digitization of the AEC industry. 

Digital twins can incorporate building information models (BIM), 2D information, schedules, contracts, construction documents such as submittals and operational data collected by embedded sensors. When assets are deployed or construction is commissioned, a digital twin can be continually updated with ongoing operational and process data such as maintenance and performance records and IoT sensor information. 

The Role of Surveying in Digital Twins

The role of the surveyor in the emerging digital twin environment has changed considerably. Changes in data collection and processing are broadening the survey role beyond simply capturing information in the field. Surveyors today incorporate aerial data, lidar scanning and mobile mapping systems to deliver highly detailed, digital twin models that represent the current physical world. 

The model serves as a fully connected environment from which planners, designers, engineers, and workers in the field can operate in concert. This kind of digital collaboration ensures that everyone understands the current status based on common data, which reduces errors and costly rework, setting the stage for true digital twin representations that can be used to manage and improve physical assets. 

In many cases, it will be the surveyor’s responsibility throughout a project to ensure the spatial integrity of all that is built—in effect, the development of the spatial digital twin. While a digital twin is a virtual representation of its physical counterpart, a spatial digital twin adds a holistic,  dimensionally accurate and location-based representation to the model. Per a recent World Geospatial Industry Council (WGIC) Policy Report, spatial digital twins can cover buildings, clusters of buildings or other infrastructure, entire networks, cities, countries, and even the globe.

DOTs Take the Lead

In construction, a digital twin is the new handover that will eventually replace the current set of 3-ring binders with product documentation that the owner/operator receives at the end of the construction phase. 

In the current cases, the digital twin often begins with a 3D model. Ideally, it’s a data model that can be used to find as-built documentation (a “spatial database,” if you will), to plan/analyze space utilization and—most importantly—to receive IoT data for operation of installed systems. 

The foundation for this virtual duplication of real space is already at work. For instance, digital as-builts are a key part of the Federal Highway Administration’s (FHWA) Every Day Counts program to identify and rapidly deploy proven-yet-underutilized innovations that make the transportation system adaptable, sustainable, equitable and safer for all. According to FHWA, a digital as-built is the as-constructed model, or the collection of project information collected/saved for downstream business needs, and a snapshot contributing new project information to a digital twin, which is subsequently used for lifecycle asset management and other purposes. 

Some transportation agencies, including the Colorado Department of Transportation (CDOT) now require all right-of-way utility work to be sent to the agency as a digital as-built. They use the data to improve worker safety by identifying the exact locations of potentially dangerous underground utilities. Further, according to the FHWA, Iowa, Minnesota, and Utah DOTs are recording as-built information on assets during construction. Michigan DOT is developing a digital as-built approach for utilities during permitting. Several states, including Oregon, Indiana, Montana, and California, are working to incorporate digital data into more effective construction delivery and management workflows. DOTs in New York, Iowa, and Utah are providing contractors with enhanced contract documents using the 3D model as they consider more integrated and streamlined approaches to project delivery. 

Digital Twinning Cities, Countries – Even the Planet?

One of the hottest development areas for digital twin technology is site-specific modeling. One of the most famous to date is the digital twin of Notre Dame Cathedral, both before and after the 2019 fire that is helping designers and contractors rebuild. Skanska USA used a digital twin to provide its customer, the University of California, San Francisco (UCSF), visibility on the construction of a student housing project. A digital twin was also used to help contractors to model the workflow and safety properties at biotech facilities to produce the COVID-19 vaccines. Skanska has since used the digital twin approach on additional projects including a weather balloon facility at Camborne in Cornwall. The digital twin, created from laser scans, includes operational and maintenance data. 

Spatial digital twins are also the foundation for smart city planning and measuring national and global carbon emissions. Here are just a few other initiatives that build on the potential of digital twins.

• Smart City Synchronicity

Digital twins also are becoming an integral part of smart city advancements around the world. The American Planning Association featured an article in 2021 that defines a smart city digital twin as a living digital replica of a city that is continuously updated with real-time data and analytics on interactions between humans, infrastructure and technology. 

By generating feedback loops of human-infrastructure interactions, these digital twins enable city governments and planners to make hyperlocal data-driven decisions, incorporate community and stakeholder priorities and evaluate policies and initiatives through "what if" scenario analysis and prediction. The digital twin is ideal for studying population growth or climate change.

• Maximizing the Whole-of-Nation

A smart city digital twin is already in evidence in Singapore. Virtual Singapore is a 3D digital replica of the city with real-time dynamic data developed by the National Research Foundation, the Singapore Land Authority and the Government Technology Agency. This whole-of-nation approach collectively maximizes the use of geospatial information and technology and makes authoritative geospatial data available for decision-making, public security and cost-effective businesses.

• Modeling the Earth

U.S.-based non-profit Earth Archive is using airborne scanning technology to create a 3D digital twin of the planet, which the organization’s founders say will provide a baseline for measuring global sustainability initiatives. One of its first projects was the scan of the Muir Woods National Monument’s redwood grove in the Golden Gate National Recreation Area in the San Francisco Bay Area. A high-resolution LIDAR scan has been used to document current conditions (e.g., count the number of trees) in the park and to construct updated estimates of biomass and carbon within the National Monument. 

Digital twins built with spatial data will connect all stakeholders with information, allowing them to better understand the physical world and make more informed decisions.