What is the first thing that comes to mind when you hear the word imagery? I bet many people will say, “I want to see my house!” People like the experience of seeing their house in 3D and then spinning the image around to see what their house looks like compared to their neighbors. Others might say, “satellite images from space.” Others might think about photos or even videos. Of course, they are all correct. Imagery is all those things and more. But, I like to think of one word when I hear imagery.
Discovery.
Discovery is particularly true for the use of imagery at utilities. Imagery can help us discover something we don’t know, like uncovered issues, where hidden hazards lurk or opportunities lie. Imagery can be an answer to a utility’s question. Questions include the best place to build a substation, a transmission line, or a microgrid. Or it helps to answer questions like “Where will my transmission tower footings be undermined by a landslide or flood?” Imagery is powerful, but combined with GIS, the two can be transformational.
The Value of Combining GIS with Imagery
One of the most common utility tasks is inspection. It is tedious, expensive, labor-intensive, time-consuming, and frankly boring for those of us who have done it. Yet, knowing equipment condition is critical for smooth operations. Equipment failure causes disruptive outages, frustrated customers, and unbudgeted expenses. Since a utility has so many parts and pieces, it becomes tough to get a complete picture of the asset condition simultaneously. That is where imagery comes in using drones, satellites, and land-based remote sensing. Combined with GIS and machine learning, inspections give a comprehensive view of asset conditions nearly at the same instant in time.
Electric Transmission Insulator Inspection
Inspection of each transmission line is critical since even a small failure could cause a massive power outage. A critical transmission line component is the insulator that separates the high-voltage conductor from the support structure. A common support structure is a steel lattice tower. There are a variety of insulators used on power lines. Transmission insulators consist of a string of non-conducting insulator disks connected to form an insulator string.
Typical transmission structures Illustrate both vertical suspension and horizontal strain insulators.
The transmission line inspection process should identify damage or contamination to one or more disks. A common process is visual inspection by walking the transmission right-of-way or by aircraft survey. Walking the line can be tough, given the rough terrain. Aircraft surveys can also be difficult since the aircraft can’t get close enough to pick up details. In both cases, inspection crews can take photos, leveraging image processing, but this process can be hit or miss. A small crack in one of the disks creates a weakness that can grow over time. Missing that small crack can lead to a transmission line failure.
The good news is that image processing has taken big leaps. Drones and high-resolution imagery have matured rapidly over the last several years.
GIS and Image Management
The bad news is managing the huge volume of imagery has been haphazard. We all have junk drawers. It’s easy to store stuff like old keys, no longer valid receipts, and outdated batteries. It’s not so easy to find stuff. Haphazard imagery storage often results in a digital junk drawer, where access is not straightforward. What utilities must know is the location, the resolution, and the age of the imagery.
This is where GIS comes in. ArcGIS Image Server for ArcGIS Enterprise users specify a particular location, such as a tower location. Then, they can access all the imagery, including past images of the same location. Then, GIS determines the content of the area of interest and the context. It helps answer questions about damage patterns and the environment surrounding the location of interest. It can also bring additional information layers, such as the closest right-of-way access points.
GIS properly catalogs the images. It does so regardless of the source (drone, satellite, land-based photos, videos from aircraft). It then geolocates and associates the images with GIS data of transmission assets. This technology solves the digital junk drawer problem. An example would be an insulator string near salt water subjected to offshore winds. Finally, this information becomes part of a machine learning training data set. That training data set uncovers other insulators from a huge imagery data set that shares the same patterns.
Examples of imagery used to analyze damaged transmission insulators
Thinking of Imagery for Utilities in a New Way
Say a utility wants to know the exact location of one of its assets for asset management, emergency management, or design. Object data extraction can interpret equipment directly from the imagery. What if a utility wants to understand the impact of flooding on its assets? Image analysis includes identifying boundaries, shapes, patterns, details, textures, and densities.
And, of course, the obvious use of imagery is for visualization. But, an imagery system is not just about viewing a picture, like finding your house in 3D. It’s about content creation, cataloging, image processing, analysis, and extracting useful data. To do what? Together with GIS, it’s about making better decisions faster and more accurately about all aspects of the utility business.
Check out this webinar, starting at 15:06, which discusses the imagery system and demonstrates imagery analysis. Also, view Esri’s Electric Utility website, which describes how GIS provides the tools to transform the electric utility business by leveraging the power of location.