What Is the Importance of Geoid in GPS Surveying?

Mar 23, 2022 | GPS Surveying

If you are looking for a surveying company, you may be interested in the specific equipment, techniques, and measurements that the land surveying firms use. One factor that some surveying technicians consider when relevant is the “geoid.” To understand the use of geoids and their importance for a GPS survey, it helps to gain a more in-depth understanding of it.

A simple explanation of the “geoid” is that it is a model utilized by surveyors to measure surface elevations with a very high degree of accuracy. As such, it is a useful tool for the relevant surveying methods. 

 

What Is the Geoid?

When it comes to understanding geoids, keep in mind that the Earth is not a perfect sphere. Due in part to the planet’s rotation, the radius of the equator is larger than that of the poles. As such, the Earth is closer in shape to an ellipsoid. However, it is not a perfect ellipsoid due to the presence of topographical features like mountains, valleys, trenches, and plateaus. These topographic variations of shape, size, and mass distribution contribute to the shape of the world’s liquid environment.

Within that liquid environment, if all tides and currents stopped occurring in the oceans, the apparent surface of the planet would settle into an irregular shape. This shape is called the “geoid,” which is visualized as an imaginary sea level surface (or “zero elevation”) and represented as a wavy surface over the planet. Through land-based gravity readings and complex equations, Oklahoma surveyors extend the geoid’s zero elevation across continents.

 

How Do Geoids Relate to a GPS Survey?

 

The Use of the Geoid in Surveying

Because the geoid acts as a model of an exact sea level surface or zero elevation, it can be used to make highly precise measurements of surface elevations. This deep understanding of the planet’s exact shape can be highly useful in some surveying projects, such as civil engineering works.

Although geoid models are designed on a global scale, they are often developed and utilized for local or regional areas. In this situation, the geoid will not be the only tool that a surveyor technician uses. However, an experienced technician may use the data that comes from the geoid in addition to their survey techniques to yield precise results.

 

What to Know About GPS Surveys

GPS technology is utilized for a variety of surveying projects, such as:

  • Determining property lines and boundaries.
  • Creating highly precise maps.
  • Gathering essential construction information.

By using satellite signals to pinpoint exact locations, Oklahoma surveyors can present highly accurate data quickly and efficiently.

The geoid and the equations used with it are just one potential aspect of this type of survey. Overall, there is an extremely wide variety of technologies, equipment, and techniques utilized by survey technicians.

Surveying equipment cases

Other Technologies Used in Land Surveying

While the geoid and advanced GPS technology are essential for surveying, a skilled technician will likely use a variety of specialized tools to obtain complete and verifiable survey results.

  • Total Stations. These optical instruments provide precise angle and distance measurements.
  • Digital Levels. These are utilized by surveyors for establishing precise height differences and elevations.
  • Surveying Software. This software processes, analyzes, and integrates data from the surveying instruments, transforming raw field measurements into comprehensive maps, plans, and 3D models.

Ultimately, the specific combination of technologies and techniques employed for any given project is a strategic decision made by the land surveyor OKC. Factors such as the project’s scale, site conditions, and unique needs or challenges dictate how the survey is conducted. The surveyor uses their training and comprehensive knowledge of each tool’s strengths and limitations to select the most efficient and effective approach.

 

Looking for a Land Surveyor OKC?

At Sisemore & Associates, our team of experienced survey technicians has the knowledge and expertise to get you the data that you need. Get in touch to learn more about our land surveying and civil engineering services.