January 2006, Issue #45
Feature Story: Surveying Engineering
When you think of surveying, chances are that images of George Washington working in the backwoods of Virginia come to mind. Or maybe you think of the surveyor who established your family's property boundaries when you moved to a new house. Although the concepts are the same, the technology for surveying has changed dramatically from the days when George Washington, Thomas Jefferson, and Abraham Lincoln surveyed the landscape. Surveyors' basic tools now include lasers, global positioning system (GPS), and the use of photographs.
New surveying technology provides three primary advantages:
- Work smarter—Work faster. New technology allows surveyors to work faster, so more things can get surveyed.
- Accuracy Despite Obstacles. It increases the accuracy of the measurements—can measure around such obstacles such as mountains and buildings.
- Brawn to Brains. It lightens the load of equipment that must be carried in the field, but elevates the level of mathematics required from trigonometry to calculus.
- Curves Considered. For larger projects, such as roadways or long bridges, surveying techniques now take into account the curvature of the earth.
"Surveying is still primarily the art of measuring and locating and analyzing those measurements to find out how accurate they are," said Professor Steven Frank of the Surveying Engineering Department at New Mexico State University. Why is it interesting to young people? "It's a good combination of using math and computer skills and still being able to go outside. Most of our students want a job where they can work with math and computers and still go outside. Most are used to spending lots of time outdoors hunting and hiking and things like that," he said.
New Mexico State University:
What is Surveying Engineering?
Surveying engineering involves the application of knowledge to the analysis, design, and execution of surveying and mapping projects and the design of land mapping and information systems. Surveyors rely on an understanding of the science of surveying measurement and analysis, the legal principles of boundary location, the laws related to boundaries and land use, and applicable mathematical and computational theories and principles when performing this work. Positional accuracy, land planning and development concepts pertinent to subdivision of land and property surveys, land record and land tenure concepts as well as earth-related sciences such as geodesy are each a part of professional surveying. Surveying engineers work for private surveying or engineering firms, for city, county, state or federal highway departments, for state lands commissions, for the U.S. Forest Service, and for the U.S. Bureau of Land Management. |
Trig to Calculus
The fundamental basis of surveying is trigonometry—using triangle to calculate measurements. But today, the field requires calculus and statistics as well. "We're now taking a lot of the trig operations that were being done one at a time and doing them in batch mode," says Professor Frank. "We used to measure one triangle. Now with GPS we have a moving satellite and two points on the ground—one point where you know where it is, the other point where you're measuring where it is and the satellite keeps moving." Thus, surveyors are now measuring a triangle from the satellite to two points on the ground, and they're measuring hundreds or possibly thousands of satellites. You can't do that with trigonometry. With the use of satellites, surveyors can get the exact distance between two points even if they're on the opposite sides of a wall—or a mountain.
Laser Technology for Shorter Distances
Surveyors now use laser technology, too. Lasers are accurate for distances up to several thousand feet, according to Professor Frank. While they're not quite as accurate as satellite readings, they're much more accurate than a tape.
Accuracy Enhanced
According to Professor Frank, 30 years ago if a survey was accurate to 1 foot in 10,000 feet, that was considered a pretty good survey. Today with GPS, rarely will professionals accept a survey that's less accurate than 1 foot in 100,000 feet—maybe 1 foot in 1 million feet. The accuracy of the technology has really taken off. With GPS technology surveyors can measure 30 to 40 miles before they begin to experience any problems.
Satisfying Work
In addition to being able to work outdoors, Professor Frank says that survey is satisfying work. As a surveyor for many years, he particularly enjoyed doing something that benefits society—such as being part of building a highway or a bridge.
Detective Work
Lots of people think that property lines are always where the fence posts are. Surveyors often find that's not the case. For most surveyors, Professor Frank says that's probably one of their favorite types of surveying. They have to go out and hunt on the grown and find where the iron pins are. Then they go to the courthouse and pull up deeds. "It's like being a detective," he says. They find all the written records, then go out in the field, and put all the clues together to come up with a profession opinion of where the property boundaries really lie. Boundary disputes quite often go to court, and surveyors go with them to testify and present their professional findings. A judge will usually decide, but sometimes a neutral party professional surveyor will serve as the arbitrator.
Photogramtry
Photogramtry is applying surveying principles to photographs. It takes measurement from photographs, which is particularly useful when you don't have access to the land you are surveying. The military uses this technique frequently. For example, Iraq was mapped completely before soldiers were sent in. Photogramtry can measure more than linear distances. Taken correctly, photographs can also be used to determine how high a building is, for example.
Geodesy—Columbus Would Agree
As Columbus discovered, the earth isn't flat. Geodesy is how surveyors make their measurements fit on a curved earth. All four-year surveying programs include geodesy. This is another area in which surveyors use calculus. This higher level of math is needed to make the mathematical corrections to round the straight measurements over large distances, so the measurements fit when you lay them out over the real ground. If you try to connect two ends of a road 30 miles apart or segments of a large bridge using flat earth surveying, the ends won't meet.
Majoring in Surveying Engineering
A typical four-year program includes all aspects of surveying—from laser surveying and GPS to photogramtry, boundary surveying, and construction surveying. A handful of universities have free standing departments of surveying engineering. Most other programs are located with the department of civil engineering. A few are located within the agricultural or computer science departments.
Famous Surveyors
Reading the list of famous surveyors might lead you to think that becoming a surveyor is a good way to achieve prominence in life. Leading a long list of surveyors who have become have achieved historical significance are George Washington, Thomas Jefferson, Abraham Lincoln, Henry David Thoreau, Danielle Boone, Captain James Cook, and Walt Disney…to name only a few.
Links of Interest:
Boundary Surveying. Brothers have killed over it. Wars have been fought over it. Neighbors have fenced it. George Washington, Thomas Jefferson, and Abraham Lincoln surveyed it. It has been stated that over 70 percent of the world's economy is based on land transactions. The largest branch in surveying involves the creation, delineation, and retracement of land boundaries and is called boundary, land, or cadastral surveying. The oldest types of surveys in recorded history are boundary surveys, which date back to about 1400 B.C. More
Mapping the World and Beyond. Imagine that you are planning a trip in a foreign country. Two items you would probably wish to carry along are a map and compass. With the map, you can locate yourself and with the compass and simple pacing, you can navigate from location to location as depicted on the map. This process is known as orienteering and is similar to the surveying process used in making maps. From ancient times, people needed to map our planet. More.
Applications in Mathematics. Traditional surveying observations consist of angles and distances to points. For example, assume a surveyor is hired to map the footprint of a building. The surveyor could use a tape to measure each side and by simple addition determine the perimeter. However this would leave the angles at each building corner unmeasured. Since it is impossible to occupy the corners of the building to measure the angles, surveyors establish an arbitrary, local coordinate system that surrounds the building. More.
