GeoVantage Displays Evolutionary Technology, Revolutionary
Concept
By Senior ANN Correspondent Kevin R.C. "Hognose" O'Brien
Andy has flown a lot of missions in the Cardinal. "I have a lot
of test flights programmed in here," he explained. He frequently
flies to check out changes to the camera unit of the software. "My
co-workers' houses, mostly. I think I have the coordinates of every
GeoVantage employee's house..."
The pilot does have to arm the system and select the mission to
be flown. Rather than a touch screen, the system works with an
ordinary flat-panel monitor and a regular mouse. "We use these
now," Andy said, pointing at a generic 15-inch flat panel. "They're
cheap. We tried touch screens," Andy said. "They were always
breaking. They are heavy, thick, and expensive. And they break a
lot. At one point we needed to make a flight and the touch screen
was broken. So we sent somebody to a computer store to get a
regular Microsoft mouse... it worked so well we stuck with it." The
buttons are large, easy to read -- and click -- in flight.
The Desktop Side
When the pilot completes his course -- he can see this on the
generic 15-inch monitor -- he heads for the barn, and possibly his
part of the mission is over. But the development of the imagery is
just beginning.
The removable HD in the computer in the plane contains ".IMG"
files, which contain all images, and ".IMU" files which contain the
DGPS and IMU data. All these data together contain most of what is
necessary to process the pictures into an exact georeferenced
image.
At the processing location, which can be as simple as a USB
external removable-drive dock attached to a laptop (which is how
Andy demoed it) or as complex as you like, a technician (maybe even
the pilot) docks the removable drive and runs GeoTrace, a
proprietary program of GeoVantage's.
In GeoTrace, you load the IMG and IMU files just like loading
documents into Word or Excel. GeoTrace also incorporates digital
terrain elevation data, which lets it correct for the vertical
variation in the terrain. With these inputs, it stitches and
"rectifies" the images into a single photomosaic. Under the hood,
it's all number crunching:
considering the variables, this has to be the worst trigonometry
program I ever heard of, and my hair follicles ache just to think
of it. But the incredible power of modern computers means that in
just minutes GeoTrace produces an absolutely exact, georeferenced
image of the target area.
"Georeferenced" is the important concept here. Because the
industry-standard output file contains the image and has it located
absolutely in reference to the physical world, it can be imported
into many GIS applications such as ArcView. The utility of this is
almost endless -- you can easily determine very exact positions of
anything in the picture. You can determine the distance and azimuth
from one item to another with laser accuracy. You can determine the
area of a stand of trees or wetland. And you can do all this with a
few clicks of the mouse.
A GeoVantage image appears as a single image, even though it was
made from a mosaic of many images -- it lacks the dividing lines
and changes in exposure that you've probably seen in military
photomosaics.
Ideas come tumbling, unbidden: there are an awful lot of uses I
can imagine for this slick technology. Andy grins: he can see
people starting to get it.
The Presentation Wraps
The presentation concluded with a Q&A session; the attendees
included GeoVantage staff from CEO Staffan Ericsson on down, local
and national media, Boston-area GIS professionals, at least one
professional surveyor who was excited about the utility of a tool
like this, and not least, local pilots, many of whom already knew
Andy Lee.
A few hints of the future included a look at a mock-up of a
next-generation camera, and some hints at future, wider
applications.
For Andy, having a job that requires occasional flying is a very
good deal; he's one of those guys that doesn't really need a reason
for flying -- a flimsy excuse will do. His father, Bill Lee, has
been bitten by the flying bug, too, and was coming in later that
day for a lesson. "He keeps asking when he gets to fly 'our'
plane," Andy says wryly. "When did it become 'our' plane?"
GeoVantage is a privately held corporation, established by
long-time remote imaging professionals in 1998. It's home-based in
Swampscott, Mass, on the Atlantic Ocean, and provides its imagery
as a service to customers worldwide, in forestry, agriculture,
environmental science, and urban planning sectors.
General Aviation Services, where the event was held, is a
full-service FBO that is celebrating its 20th year at Beverly
Airport. (Its offices are in a landmark hangar dating to 1928,
although the Navy moved it 100 yards to its current location in
1941 -- no sense of history, the Navy). It offers fuel, Part 135
charters, a Part 145 maintenance shop, flight training, and
aircraft rental, hangars and tie-downs.