COLUMBIA CITY, Ind., June 3, 2002 — Northeastern Rural Electric Membership Corp. (Northeastern REMC) was able to map 60,000 points in less than a year as part of a GIS project.
The Geographic Information System (GIS) project included the daunting task of mapping the utility’s entire 600-square-mile service territory.
Northeastern REMC is a consumer-owned electric cooperative serving in Columbia City, Indiana, supplying electric power to 20,000 households and businesses in Allen, Huntington, Kosciusko, Noble, Wabash and Whitley counties in the northeastern part of the state. Its service territory includes two of the highest growth areas in Ft. Wayne. The company has an ongoing need for a comprehensive GIS to maintain its facilities and provide dependable service to its customers.
For utilities, accurate GIS is critical. In a power outage, for instance, field people without accurate maps may not be able to find faulty equipment quickly. That impacts customer service and prolongs outage times.
Pre-GPS, the company’s old mapping system consisted of 150 separate drawings. The maps, with no data attached, were inaccurate and outdated. Worse, only 25 percent of the utility’s service territory was actually mapped, and that without any specific map grid.
“Recent development was a big reason the maps had become outdated,” said Steven Weber, coordinator of development for the new GIS for Northeastern REMC. “Adding more customers meant the addition of more service facilities and equipment, and the old mapping system became more obsolete with each addition. As we tried to update our drawings, we couldn’t fit the new subdivisions into the old maps. That’s when we started looking into GPS to help map the facilities.”
The location of every piece of equipment the company owns was entered into the new GIS mapping system. “It took 60 years to install all this equipment, and we were able to map it accurately in just two,” he said. “We simply couldn’t have done it without GPS.”
Originally, the company planned to use GIS as an engineering tool to accurately locate all its poles and transformers for engineering analysis. “GIS told us exactly how far each piece of equipment is from the next,” Weber said. “We needed to know exactly where our wire was, how much there was and its size. In the past, we’d made rough measurements by pacing or using a measuring wheel, but we felt only GPS could provide the level of accuracy we needed for our engineering model.”
Once they began looking into GPS, Weber and his associates considered other applications. “For example, we could have the mapping system accessible in trucks for line crews to use in the field,” Weber said. “We thought staking engineers would probably like to have this information, as well, and customer service staff could use it in the office. Essentially, we started to understand that the GIS would be an auxiliary to our database that could be used by the entire company.”
In the long run, the new mapping system is designed to make Northeastern REMC more competitive. Every employee will eventually have access to an accurate, comprehensive database and corresponding maps to help improve productivity and customer service.
Collecting Data with GPS
The first step in developing GIS was the collection of data. For that, the company chose the Reliance Decimeter System from Thales Navigation. Reliance proved to be a field asset management tool that was flexible and accurate enough to provide dependable data when and where they needed it. With 60,000 points to collect, Northeastern REMC’s GPS technician and Pathfinders, the GPS service contractor, were out every day with roving Reliance devices, collecting as many points as possible.
The Reliance GPS receiver was mounted in a vehicle or on a bicycle, or carried in a backpack for going on foot. The equipment was set up for what was needed on a daily basis.
The customized bike mount was a re-engineered marine bracket originally used for mounting depth finders on fishing boats. Reliance was mounted to a mountain bike for rural areas, where the points were farther apart but couldn’t be collected easily with a vehicle. The GPS technician in the field had the power and flexibility to easily reach most offroad points. Biking technicians alone were able to collect 120 points each day with the device.
The GPS technician also used a specially equipped minivan. Where points were closer together in developed areas, he could detach the Reliance receiver and place it in a backpack for walking. It took between 5 and 10 minutes to transition from one mobile setup to another.
By walking or riding the bike, the GPS technician also had minimal impact on the land of Northeastern REMC’s customers and the municipalities, and it eliminated traffic disruptions normally caused by standing vehicles.
Whether driving, riding or walking, the technician occupied the point as close as possible, and if necessary, shot an offset with a laser range finder and electronic digital compass. He then entered those measurements, as well as attribute data, into the Reliance system while collecting the point with the GPS receiver. At the end of the day, the data was simply downloaded into the home base GIS.
“The technician had access to an electronic survey tool station for hard-to-reach areas that made GPS readings difficult,” Weber said. “Occasionally, a GPS technician was unable to acquire an accurate reading with Reliance – due to heavy tree canopy, for example. There we simply sent our contractor in with a powerful Thales GG-Surveyor system. Problem solved.”
Technicians brought the points into the map daily. The automated mapping tool was AutoCAD Map, enhanced with GenMap software by Gentry Systems. GenMap provided an interface between AutoCAD Map and the company database.
“From the Reliance GPS, we downloaded an ASCII text file into AutoCAD Map, a task supported by GenMap’s import function,” Weber said. “The system then combined coordinate and attribute information into an AutoCAD block. Each point is now designated by a symbol that can be clicked to access point attributes. For example, each customer on the map is represented by a meter symbol, with attached attribute data such as name and address, and even information about the transformer serving that customer.”
For the engineering model, the group used Windmil®, an electrical modeling and analysis software from Milsoft. All of the systems were easily integrated to exchange data seamlessly, from Reliance to the mapping and engineering analysis systems.
Maintaining Data Accuracy
“High accuracy was one of the main reasons we selected the system we did,” Weber said. “We found that when we stood at a point with Reliance for about a minute and a half, we could easily achieve accuracy within two feet. And we’ve proven the accuracy with repeated measurements. Measuring the point repeatedly would create a scatter pattern of only three feet out in the open. If the point was near tree cover, we had to occupy the site for a slightly longer period of time, as we would with any GPS equipment.
For the GIS project, the company needed submeter accuracy, and the Reliance system consistently provided accuracy of about two feet or less.
A key to obtaining accurate measurements is to have good satellite coverage. With access to more satellites, the GPS receiver can collect more accurate data faster. “That meant that we wanted to be occupying the points, collecting GPS data, when the most satellites were overhead,” Weber said. “That happens at different times of the day, depending on the satellite schedule. We used the Thales Mission Planning module, a feature of the Reliance processor, to help us plan each day for the best coverage.”
Thales Navigation, headquartered in Santa Clara, Calif., is a subsidiary of Thales, a professional electronics company headquartered in Paris, France, with activities in aerospace, defense and information technology and services. For more information, visit www.thalesnavigation.com.