Surveying represents an essential aspect of construction, where accurate measurements are paramount. While most consider it a science, a very precise one, others would say that it is art. Whichever way you decide to look at it, you can complete a surveying task without the right tools for the job.
Being that precision is key in surveying, there are two methods that have emerged as the most commonly used ones today - Total station surveying and GPS/GNSS surveying. While both methods are useful in collecting data, there are many differences between the two as well as situations where it it better to use one instead of the other.
We will try and explore the main total station surveying vs GNSS surveying in this article before you today, which should help you determine which one to use in specific surveying situations that you may find yourself in.
Total Station vs GNSS Surveying
Both GNSS receivers and total stations are very effective in collecting data. However, the two are actually much more satiated for completely different uses. Many professional surveyors are actually turning towards the use of GNSS equipment and accessories because it provides them with a bigger overview at greater speeds, total stations still provide higher accuracy and do not depend on satellite use.
In a perfect world, a hybrid GPS total station surveying would work best. But since we don’t get many of those, it is best to pick one depending on the circumstances.
Total Station Surveys
A total station is an instrument used in surveying that combines the use of a theodolite, an electronic distance-measuring device, and a measuring tape. This tool is used to measure various angles and distances, and you usually see it used with a data collector or a computer that helps to record, store, and process the collected data.
A total station comes with a telescope, which should be pointed at a target, in order to determine the distance to the target with the help of electronic distance measuring (EDM) technology. It also comes with a built-in theodolite, allowing it to measure horizontal and vertical angles. The gathered information is then used to calculate the coordinates of a given target.
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Total Stations |
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Total Station Survey Advantages and Disadvantages
Total stations have been around for much longer than GNSS technology has. For that reason, but for that reason alone, they are considered much more accurate, especially within land surveying use.
Total station surveys require a manul process to get things done, due to the use of the line of sight which also means that it has a much smaller working area. Luckily, thanks to the advancements in surveying technology, now we have robotic total stations that help capture imagery by eliminating the need for revisits.
Its range might be more limited, but it still offers accuracy within 5mm-100mm.
Advantages of Total Station in Surveying
- High precision: Total station surveys are much more precise, which means that they are perfect for projects that require pinpoint accuracy.
- Can be used in difficult-to-access areas: Total stations can be used in areas that are hard to get to as long as the survey can clearly see the target, including steep slots and dense forests. The
- Versatility: Total stations can be used for different surveying tasks, including construction layout, topographic surveys, and as-built surveys.
- The ability to measure both angles and distances: Total stations are able to measure both angles and distances, making it possible to calculate coordinates for any point.
Disadvantages of Total Station in Surveying
- Limited range: Total station surveys have a limit when it comes to range, usually around 2,000 meters (6,561 feet).
- Cost: Total station surveying can be a bit expensive, as the surveyors involved may need specific training while the equipment itself can be somewhat costly.
- Limited by visibility: Total station surveying is limited by visibility, meaning that it cannot be used in areas where the target is obscured by any obstacles.
GNSS Surveying
GNSS surveying, which people also refer to as GPS surveying, uses satellite-based positioning systems to determine locations on points. GPS surveys only use the Global Positioning System, while GNSS surveying equipment can use GLONASS, BeiDou, and other satellite positioning systems besides GPS.
When it comes to GNSS surveys, a GNSS/GPS receiver is used to collect data. The receiver collects the signal from various satellites and with the gathered data uses it to calculate the point on the earth’s surface.
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GNSS/GPS Receivers |
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GPS Surveying Advantages and Disadvantages
GNSS surveying is perfect for large sites with an open sky, making it perfect and most convenient for large data collection. If you mount it to a vehicle or a GNSS pole, you can collect data even quicker, making it even more appropriate for field surveying.
GNSS receivers are also easy to set up and operate. They provide a much greater coverage than total stations and you don’t even need to have the object you are targeting in your line of sight. Its accuracy measures between 10mm to 30mm, both horizontally and vertically.
GPS/GNSS Surveying Advantages
- Wide range: GNSS surveying has a very wide range, making it suitable for surveys of much larger areas and at greater speed.
- Cost-effective: GNSS surveying is relatively cost-effective, the equipment used is relatively cheap, and surveyors don’t require any specialized training.
- Can be used in areas with limited visibility: GNSS surveying can be used in areas where visibility is limited, including places like dense forests or urban areas.
GPS/GNSS Surveying Disadvantages
- Limited precision: GNSS surveying has limited precision, which means that it is not really suitable for situations that require very accurate measurements.
- Requires a clear view of the sky: GNSS surveying requires a clear view of the sky, making it ineffective in places where the sky is obscured, including underground mines or very densely populated areas.
- Depends on satellite signals: GNSS surveying is dependent on satellite signals, making it susceptible to factors such as the presence of tall buildings or atmospheric conditions.
Difference Between Total Station and GPS Surveys
When comparing GPS vs total station surveys the one thing to know is that you can’t always use both of them for any type of job. Total stations are known for their precision and versatility, making them suitable for projects that require the utmost precision. Unfortunately, its limited range and visibility prevent it from doing larger types of tasks.
On the other hand, GNSS/GPS surveys have a much wider range, allowing them to be used even in areas where viability is limited. Unfortunately, you don’t get the same precision as you would with total stations, and it is dependent on satellite signals, preventing you from using them in all types of places.
Total Station vs GPS Comparison
To give you a much better perspective between the total station vs GPS comparison, it is better to go in detail through every part individually.
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Total Stations |
GNSS/GPS |
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Accuracy |
Very high accuracy, usually in millimeter or centimeter range. |
Lower accuracy, but it can varry. Standard GPS has accuracy in meters, while RTK offers accuracy in millimeters. |
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Precision |
Provides precise angle and distance measurements |
Not as precise, except RTK which can offer better results. |
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Spatial Coverage |
Limited coverage, better suited for localized areas. |
Comes with global spatial coverage, except in dense urban areas. |
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Working Environment |
Most suitable in environments where a direct line of site can be established. |
Ideal for topographic mapping and various environments involving vast terrains. |
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Data Collection |
Requires direct line of site to collect data. |
Relise on satellite signals. |
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Speed & Efficiency |
Slower due to requiring manual setup and target placement. |
Much faster data collection over vast areas. |
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Cost |
Equipment needed can be a bit costly, especially if you include maintenance and labor costs. |
Standard GPS is affordable, but RTK can be costly. |
Total Station Surveying vs GNSS Surveying Conclusion
As you can see, the total station surveying vs GNSS surveying debate is not as cut as you may think it is. Both of these are cutting-edge systems and are used by professional surveyors all the time. The eventual right decision will ultimately depend on you and the needs of the job that you are planning to do.
Having the right tool for the job will eventually guarantee results. So your task is to determine which of the two will be more suitable for the survey you are about to perform, which will lead to you getting the most appropriate results. All in all, both types of surveys have their advantages and disadvantages, so you need to choose carefully as you understand the terrain you are about to go on to.
FAQs
For a few more interesting pieces of information about the topic, check out the lines below.
What is a total station surveying?
Total station surveying is a method of surveying that uses a total station instrument to measure distances, angles, and elevations between points. It combines an electronic theodolite (for measuring angles) with an electronic distance meter (EDM) for measuring distances.
What is the difference between GPS surveying and total station?
Both GPS and total stations are used for surveying purposes, but they operate on different principles. GPS surveying uses satellite signals to determine the precise location of a point on Earth. It's ideal for large-scale projects and areas with limited visibility. While total station surveying measures distances and angles using a laser beam and a prism reflector. It's well-suited for construction layout, topographic surveys, and property boundary determination.
How does GNSS surveying work?
GNSS surveying uses satellite signals to determine precise locations. It's used for mapping, navigation, land surveying, and construction. GNSS systems consist of satellites orbiting Earth. Receivers on the ground capture signals, calculate position using triangulation and use correction signals for accuracy.
How to operate total station surveying instrument?
Total station surveying involves using a total station instrument to measure distances, angles, and elevations. To operate a total station, set up the tripod, mount the instrument, level it, acquire the target, measure distance and angles, and record data. Advanced features include automatic targeting, data transfer, and remote control.
Which method of GNSS surveying is more accurate?
The most accurate one involves using GLONASS (Global Navigation Satellite System), which is widely considered the most precise system available, especially when measuring in high latitudes.
