Locating Campus Steam Lines with Drone2Map and Thermal Imagery
Managing underground utilities on a campus can be challenging, especially when as-built records are outdated, incomplete, or flat out do not exist. At Brigham Young University-Idaho, steam lines are critical for heating buildings during our cold winter months and without as-builts they are often hard to locate precisely without invasive digging. We recently used drone-based thermal imaging and ArcGIS Drone2Map to locate these utilities more accurately.
The Approach: Capturing and Processing Thermal Imagery
On a cold December night, we deployed a DJI Matrice 30T drone equipped with a thermal camera to capture aerial imagery to show heat signatures across campus. The thermal data revealed heat signatures from several utilities where warmer surface temperatures stand out including our underground steam lines, heated sidewalks, manhole lids, and valve covers.
To ensure a somewhat high positional accuracy, we established ground control points (GCPs) using a Leica GS18 GPS with RTK to gather the center point of several manhole lids and valve covers around campus. The raw imagery combined with the GCPs was processed using ArcGIS Drone2Map to create a true orthomosaic that aligns with our campus. We deployed this imagery as a hosted tile layer to our Portal for ArcGIS and added it to our aerial imagery map for reference in the field using ArcGIS Field Maps.
Raw Data: Over 9,000 images were captured as part of the campus thermal data collection.
Ground Control Spread: We used 8 GCPs to ensure a good spread throughout the imagery.
Ground Control Tie Point: Tie point placed on center of manhole lid.
Real-World Impacts: Correcting Assumptions
One of our main goals with this project was to determine where our steam lines were drawn incorrectly in our steam distribution feature layer. After comparing the imagery to our layer, we identified a few locations on campus where we were several yards off. In a couple of instances, we had expansion loops drawn in the completely opposite direction of reality. Adjusting these lines has helped us to have better information for future utility locates and steam infrastructure service.
Correcting Steam Line Paths:
- Steam and condensate before adjustments using thermal imagery.
- Ensuring steam lines follow heat signature.
- Steam and condensate after adjustments using thermal imagery.
In a separate project, contractors were recently on campus trying to locate a few different buried utilities for an upcoming electrical line relocation. I happened to walk past while they were using a vacuum truck near the building I work in. I asked what they were searching for, and they answered "a steam line." I told them that they were on the wrong side of a nearby tree. They told me that this was where the utility locate claimed the steam line was and gave me a questioning look.
I opened Field Maps on my phone and pulled up our thermal imagery to show them the clear heat signature indicating the line ran on the opposite side of the tree. Within minutes, they adjusted their location and successfully exposed the steam line. This quick validation demonstrated the power of visual thermal data in real-time decision-making.
Real-time Use: Bore hole locations before and after consulting thermal imagery when trying to locate steam line with a vac truck.
Key Outcome: Better Utility Awareness
By integrating this data into our smart campus GIS operations, we're building a more accurate utility map. This supports better planning for maintenance, construction, and emergency response while reducing risks and costs. Thermal drone imagery, integrated with ArcGIS Drone2Map, offers us a non-invasive, efficient way to map hot utilities like steam lines. For campuses managing complex infrastructure, it's a gamechanger turning aerial data into actionable intelligence.