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MINES FIND NEW USES FOR SATELLITE IMAGERY
Mining and Technology Article by Harold Hough Dec/Jan 2009

Twenty years ago, satellite imagery was the new frontier for geologists, who used it to prospect for promising geological structures in remote areas. However, as the cost has declined and quality of satellite imagery has improved, more mines are finding new uses for them. “Satellite imagery is now being used in engineering and logistics,” noted Sandy Perry, owner of Perry Remote Sensing in Colorado. Sandy has been a pioneer in remote sensing for over a generation and has helped develop many of the remote sensing methodologies that are now the “norm” in the mining industry.

But, there are even more improvements on the horizon and looking into the future, Perry sees three major changes in the use of satellite data. The first major change will come in a few months as the newest Ikonos satellite finishes it’s testing and begins providing commercial imagery. This imagery will provide full color imagery plus near infrared with a resolution of 50 centimeters. “The satellite isn’t a dramatic step, but continues the progression of commercial systems,” Perry noted. “It’s also cheaper than aerial surveys in many parts of the world where getting government permits for aerial surveying is difficult.”

This higher resolution imagery allows mining engineers to monitor existing mines, make plans for expansion, monitor open pit changes, and find new sites for tailings. During mine construction, engineers can use the imagery to plan roads, pipeline routes, and power lines.

Another change in remote sensing is Digital Globe’s World View. This 50 centimeter black and white imagery is quickly acquired and easily programmed to produce Digital Elevation Models.
World View provides a dramatic improvement in Digital Elevation Models (DEMs). “They are really important in open pit situations,” says Perry. With DEMs that have an accuracy of 2 – 4 meters, mine engineers can quickly measure the size of tailings piles and the volume of an open pit mine. They also help mine management monitor the dynamics of the mine. In reclamation, they can be used to plan terracing and even be used in computer models to show what the reclaimed mine will look like. For the environmental team, they can be used to monitor the health of the surrounding ecosystem to ensure that mining isn’t doing any harm. This imagery can also be used by the company’s lawyers to prove that a mine isn’t polluting the environment.

Unfortunately, not all parts of the world are ideal for these systems. Many places have constant cloud cover or are covered by snow and ice. That’s one reason why Canada has been at the forefront of high-resolution satellite radar systems. These satellites can penetrate clouds, snow, and ice with ease to provide the mine with the necessary information. According to Perry, a new breed of radar is coming which will have a higher resolution than current systems. Although not able to offer the same resolution as traditional satellite imagery, radar gives many mining companies the ability to develop DEMs in areas where cloud, snow, or ice cover would preclude other systems. “You can wait years for a good shot in some parts of the world,” Perry said. “With radar, you don’t have to wait.”

Although these satellite systems are being used throughout the world, they are gaining the most ground outside the U.S. according to Perry. Aerial surveys are more expensive and require more bureaucratic red tape overseas than in the U.S. Here, aerial survey companies have remained competitive with the satellite imagery business. Meanwhile overseas, satellite imagery is used to update more expensive aerial surveys.
As with all new technology, lower satellite imagery prices allow mines to find new applications. What was once an exotic technology that few mining companies understood has become an everyday tool that is used by geologists, engineers, environmentalists, reclamation experts, and logisticians throughout the mining industry.