A set of eight bug eyes peers out intently at the passing landscape of metal, grass, pavement and human flesh. The metal eyes record every move below them as they pass by silently thousands of feet away, far above their intended subject.
Five thousand feet above Columbia, a $1.2 million, 450-pound Intergraph digital mapping camera captures a six-inch resolution of the ground below. The camera shoots through a specially cut hole in the bottom of a twin-engine Cessna 441 Conquest. This camera, along with the required Global Positioning System, gives the aircraft a value of nearly $3.5 million.
The crystal-clear blue skies over Columbia on Wednesday morning allowed Surdex Corp. of Chesterfield to photograph the 200 square miles of the city in about two hours, Craig Molander, Surdex senior vice president, said.
Surdex, an aerial mapping company, was contracted by the city of Columbia on June 8 to take digital orthophotos of the city, Tony St. Romaine, assistant city manager, said.
The $40,000 project is the first phase of the Natural Resources Inventory. As reported on April 9 in the Missourian, the inventory will help guide the city in a review of its conservation policies by documenting green space, tree cover and other natural features. The second phase will require the help of MU, which will analyze the imagery data.
“It’s a really nifty analysis of the city,” Molander said. “It’s a very special digital airborne camera.”
The camera produces digital orthophotos from eight different lenses, four of which shoot multispectral imagery. That is valuable for this project, he said, because “this part of the spectrum portrays the response of chlorophyll and moisture.” Healthy trees exhibit high degrees of chlorophyll and will therefore show up as a robust red color in the picture. Less healthy trees, he added, “will stick out like a sore thumb.”
About 900 photographs were taken of Columbia. Those images are imported immediately onto three large “ruggedized” disk drives on the aircraft, just like importing pictures off a point-and-shoot camera onto a computer, Molander said.
The twin-engine Cessna is one of six aircraft Surdex uses to provide aerial photography for projects across the United States. Each aircraft has a pilot and a photographer. After receiving an outline of the city, Surdex turns that outline into strips, which are oriented north and south.
In the case of Columbia, flying so low over the urban area can be a problem for the pilots because of the turbulence created at low attitudes, Molander said. The camera, however, is placed in a gyro-stabilized mount above the hole.
Besides turbulence, pilots also have to focus on three other factors while taking aerial photographs: communicating with air traffic control, the photographer and other air traffic around them, said Jon Noirfalise, Surdex chief pilot, who has flown with Surdex for two and a half years.
“It’s kinda like juggling,” he said.
Noirfalise, who was previously a corporate pilot, said he finds this type of flying to be more interesting than flying corporate aircrafts.
“It’s more challenging than flying from point A to Point B,” Noirfalise said. “I feel like I’m helping people out.”
Like the pilots, the photographers do not need special training to work on the camera during flight, said Kevin Eichelberger, Surdex head photographer. The flight plan is already programmed into the GPS system, which automatically tells the camera when to take pictures during the flight, he said.
So while in flight, the only job a photographer has is to make sure the camera works and fix it when necessary. Normally all problems in flight can be fixed through troubleshooting, he said, and 90 percent of the time that works.
“We keep a flight log and monitor the GPS,” Eichelberger said.
Throughout the summer, Surdex typically gets only four to five suitable days of flying weather each month because even one small cloud in the sky prevents a clear picture, Molander said. Specifically, Surdex cannot fly when clouds make up more than 5 percent of the camera lenses, Noirfalise said.
St. Romaine thinks Surdex’s work will greatly benefit the city in the future. “It is very important to recognize what our natural resources are,” St. Romaine said. “It is important not only for public conservation, but it is also a chance to reflect our community standards.”