--- title: "A digital twin that keeps its sources | Nexus Observatory" description: "A digital twin is a model of a physical asset kept current by observation of it1. The hard part is not the geometry; it is keeping every value in the model…" url: https://observatory.global/stories/digital-twin-site/ publisher: Nexus Observatory Inc. updated: 2026-10-31 --- [Stories](https://observatory.global/stories/)System: Digital twin of a site # A digital twin that keeps its sources A digital twin is a model of a physical asset kept current by observation of it1. The hard part is not the geometry; it is keeping every value in the model traceable to the sensor, survey or document it came from. **Systems**: Geometry and semantics, Live observation, Synchronisation **Toward 2030**: Open city and infrastructure models **Figures**: 4, field scene, layer stack, systems diagram, timeline to 2030 Go to the references **01** Field scene ## A transmission corridor as an asset. Five pylons on real terrain, the conductors between them, a substation and a weather station. The twin knows each span length from the geometry and each sag from the conductors’ temperature, which the weather station helps to estimate. Substation data follows its own standard model2. Figure as text: A transmission corridor over real terrain Five lattice pylons across a valley from elevation data, a substation, an edge node and a weather station. - Pylon - Substation - Weather - Edge **02** Layer stack ## The twin as registered layers. Under the geometry sit the layers that make it a twin rather than a drawing: terrain, imagery, infrastructure, live stations and a model output. Open models such as CityGML give buildings and networks shared semantics3; information management for built assets is itself standardised4. Figure as text: Layers of a site twin An exploded stack of terrain, imagery, land cover, infrastructure, sensors, analysis grid and model. 1. **Terrain** 2. **Imagery** 3. **Vegetation** : Vegetation near conductors. 4. **Assets** : Pylons, spans and the substation. 5. **Sensors** 6. **Clearance model** : Modelled clearance; the red line marks the limit. **03** Systems diagram ## Keeping the twin in step. Phasor measurement units report voltage and current with precise timestamps5; weather and line sensors report through the edge; surveys arrive months apart. The twin synchronises each at its own cadence and keeps the source of every value. Cut a source to see which parts of the twin go stale. Figure as text: Sources that keep a site twin current A four-tier diagram: field sources, the edge, the twin, and its users. - **Sources** : Phasor unit, Weather, Line sensor, Survey - **Edge** : Substation edge, Upload - **Twin** : Twin - **Users** : Operations, Planning 8 links. Scenarios: All sources current; Substation edge offline. **04** Timeline to 2030 ## The standards beneath a twin. A twin built on open models can outlive the software that made it. The milestones below fix its geometry, its semantics and its information management. Figure as text: Standards for digital twins of sites and assets A timeline from 2011 to 2030 with synchrophasor, substation, BIM, manufacturing twin and CityGML standards. 1. **2011** Synchrophasor measurement standard (IEEE C37.118.1). Time-stamped phasor measurements for power systems. 5 2. **2013** Substation communication and object models (IEC 61850). Data models and services for power utility automation. 2 3. **2018-12** Information management with BIM (ISO 19650-1). Concepts and principles for built-asset information. 4 4. **2021-09** CityGML 3.0 conceptual model (OGC CityGML 3.0). Semantic city and infrastructure models, including dynamic data. 3 5. **2021-10** Digital twin framework for manufacturing (ISO 23247-1). Principles for observable manufacturing elements and their twins. 1 Figure 1 Field scene **Span t2–t3**: 451 m **Corridor length**: 1.8 km Figure 1. A transmission corridor over real terrain. Five lattice pylons across a valley from elevation data, a substation, an edge node and a weather station. ## References 1. [ISO 23247-1:2021 Automation systems and integration — Digital twin framework for manufacturing — Part 1: Overview and general principles](https://www.iso.org/standard/75066.html) . International Organization for Standardization, 2021. 2. IEC 61850: Communication networks and systems for power utility automation. International Electrotechnical Commission, 2013. 3. [OGC City Geography Markup Language (CityGML) 3.0 Conceptual Model](https://www.ogc.org/standards/citygml/) . Open Geospatial Consortium, 2021. 4. [ISO 19650-1:2018 Organization and digitization of information about buildings and civil engineering works, including BIM](https://www.iso.org/standard/68078.html) . International Organization for Standardization, 2018. 5. IEEE C37.118.1-2011: Standard for synchrophasor measurements for power systems. IEEE Standards Association, 2011. ## Related stories [System: Data provenance chain **From sensor to record** A published observation should carry its own history: which instrument made it, when, under which calibration, and every step since. The web already has a…](https://observatory.global/stories/provenance/) [Place: Suburb **The suburb as a power station** Rooftop solar, home batteries and electric vehicles turn a residential street into thousands of small generators. Observing them is how a distribution grid…](https://observatory.global/stories/suburb-grid-edge/) [System: End to end **An observation grid, end to end** An observation is not a reading. It is a reading with a place, a time, a calibration and a path that anyone can follow back. An observing grid is the…](https://observatory.global/stories/observation-grid/) ## Where this applies [Digital twins and simulation](https://observatory.global/digital-twins/)[Data & licensing](https://observatory.global/data-products/)[Sensors & instruments](https://observatory.global/sensors/)[Protocol & Grid](https://observatory.global/grid-services/)[Infrastructure](https://observatory.global/industries/infrastructure/)[Energy](https://observatory.global/industries/energy/)[Cities](https://observatory.global/industries/cities/)[Insurance and finance](https://observatory.global/industries/insurance/)[Field tour: transmission corridor](https://observatory.global/environments/transmission-corridor/)[Field tour: city block](https://observatory.global/environments/city-block/) © 2026 Nexus Observatory Inc. **Legal** [Privacy notice](https://observatory.global/legal/privacy/) · [Terms of use](https://observatory.global/legal/terms/) · [Cookie policy](https://observatory.global/legal/cookies/) · [Accessibility](https://observatory.global/legal/accessibility/) · [Official languages](https://observatory.global/official-languages/) · [Notices](https://observatory.global/notices/) **Company** [About](https://observatory.global/about/) · [Open governance](https://observatory.global/consortium/) · [Contact](https://observatory.global/contact/)