What do land surveyors do other than stand behind a transit and wave their arms at other people that we can’t see, or set up traffic cones and road barriers that force us to change lanes and drive through a watery pot hole after having just washed our car?
The answer is simple. Understanding it is not.
Surveyors mark the boundaries of land, create maps and legal descriptions, and plan and organize the development of property.
We deal with a lot of important issues in our lives but the three that seem most timeless and universal are our families, our health, and our rights to our land. Our welfare is directly affected by our ability to define our space. That’s one of the land surveyor’s most important jobs, to mark, describe, and map property ownership. His or her work creates a stable framework on which we can build our homes and communities, and generate the wealth necessary to sustain those communities. If we don’t know the location of the boundaries of our land we can’t enjoy any unique use of it. We could not buy, sell, mortgage or develop land in an orderly and predictable fashion. The land surveyor provides that knowledge.
Although the rules of land surveying may vary depending on whether you practice in the states of the original 13 colonies, or in the Public Land Survey System (everything else), There’s one fundamental principle that governs our work. In the words of Justice Cooley of the Michigan Supreme Court, “ No man loses title to his land or any part of it merely because the evidence of where it once was becomes uncertain.” The perpetuation of property rights and title is tied to the land. 
Land surveyors use computers, precise measuring tools, and mapping systems to gather and analyze data (evidence) in the field. They then interpret that data to establish the most probable location for property corners. Their opinions are formed from knowledge of common law, rules of evidence, state and federal laws, and local standards of practice. In many ways it is much an art as it is science.
Another important part of the land surveyor’s professional activity involves understanding and “decrypting” the often-confusing language in legal descriptions. Just what did the author of the deed mean to convey? If you really want to get a land surveyor talking, ask him to describe how many different ways there are to go “North.” The list is probably similar to the number of words for snow in the Inuit language.
Despite the fact that there are a lot of flashy new tools available now to make expert measurers out of novices, we will never really know the true location of boundary lines if we don’t understand the value of what is being measured. That is the expertise of the land surveyor, and one of the reasons that you may see someone carrying a red and white pole (with something that looks like a Frisbee on top of it) peeking under the sod in your front yard.