As a land surveyor, accuracy is extremely important. After all, a lack of precision can be extremely costly and painstaking to correct. But, how do you know your maps are accurate and up to date? Do you always check data and measurements, or do you trust them as they are?
History of Accuracy in Land Surveys
While accuracy is an extremely important part of land surveys, it hasn’t always been a realistic part of their creation. Some of the earliest known land surveys were completed by the Ancient Egyptians in 3000 BC. They used very rudimentary tools and simple geometry, resulting in incredible, yet often inaccurate, maps.
Since then, technology has increased and so has accuracy. While the fundamental basics of land surveying remain the same, the tools we use have drastically changed. We are now able to take measurements down to fractions of an inch and use highly technical apparatuses to reduce error. But, despite all this, errors still remain.
The Value of Accuracy in Maps
Accuracy is probably the single most important factor of maps and land surveys. Because the purpose of a land survey is to determine boundaries and ownership rights, inaccuracies can lead to legal issues down the road. While all surveys should be precise, certain types require more accuracy than others. When things like hydrological features and roadways are involved, high levels of precision are required.
The Inaccuracy of Maps
Maps are actually not all that accurate, though. We may think they are, because it is all we know, but they are close estimations at best. As simple abstractions of reality, each map requires thousands of measurements to be truly accurate. While modern day mapping professionals have access to incredible amounts of information, it never hurts to have a little more.
What Is Accuracy?
According to professional surveyors, there a number of factors that go into developing an accurate map. If you can achieve all – or most – of the following six, you are in good shape:
- Area - This refers to the extent of a given feature and how it compares to its terrestrial extent.
- Position - Position refers to how close a map feature is to its actual position on the Earth’s face.
- Closure - Closure depends on the error in a given traverse for a piece of land.
- Attribute - This begs the question, are tabular attributes allocated to the right features?
- Completeness - Have all features and characteristics been mapped and labeled?
- Resolved to Unresolved - This refers to how often parcel gaps and overlaps occur.
