Total stations are often paired with other surveying equipment as part of a fully integrated surveying solution, but what are the benefits of doing this and how do different technologies work together?
Total stations are sophisticated surveying tools used for measuring horizontal and vertical angles and distances, as well as calculating elevations and coordinates. It does all this using a theodolite and an EDM (electronic distance measurement) along with built-in data processing tools.
While many agree that total stations are indispensable when it comes to surveying, other surveying technologies are still very much used. Many will be used in conjunction with a total station as part of an integrated surveying solution to provide a thorough, accurate and reliable cross section of data.
These alternative technologies include equipment such as GNSS systems, laser scanning and LiDAR technology, photogrammetry and Satellite Imagery and GIS (Geographic Information Systems).
We’ll discuss some of these in more detail below, as well as the merits of total stations in comparison to other surveying technologies.
As mentioned above, total stations are intricate surveying tools used to measure angles and distances with a high level of precision and accuracy.
The device’s theodolite is for angle measurement and its EDM for distance measurement. This dynamic duo means total stations are great for accurate data collection, both from a BIM perspective and a land surveying one, and are very useful for carrying out surveying tasks like determining land boundaries, construction setting out and topography.
They can also integrate with BIM and AutoCAD software to allow for accurate model positioning, data visualisation and digital workflows.
Applications of total stations include:
The biggest benefit of total stations is the high levels of accuracy they offer over manual measurements and the speed at which the data is collected. Robotic tool stations such as the Trimble S9 also allow for surveying and data collection in the most challenging of locations, that could otherwise prove near impossible to measure.
With the ability to pair with other surveying technology such as a GNSS receiver as part of an integrated survey solution, as well as real-time data collection that can be accessed immediately by the whole project team, it’s easy to see why they’ve become such a vital surveying tool.
Such benefits can save surveyors and contractors huge amounts of time and money, keeping errors and rework to a minimum.
GNSS – or Global Navigation Satellite System – is a constellation of satellites which transmit positioning data to receivers, providing surveyors with accurate location data. It can therefore be used for geospatial positioning, mapping, boundary determination and data collection – all with a high degree of accuracy.
GNSS surveying equipment is particularly advantageous when it comes to large-scale projects or projects in challenging terrains as its global coverage means positioning data can be acquired across vast territories. It also provides real-time data like a total station, meaning corrections and adjustments can be carried out during the surveying and construction processes.
However, GNSS technology is not without its limitations. It can suffer signal interference and accuracy can be spotty in dense urban or forest environments. This is because skyscrapers and tall obstacles such as trees can obstruct satellite signals.
The effect of this is reduced accuracy by up to a few metres, which can be challenging when pinpoint precision is required. To help prevent these issues, some surveyors also employ technologies such as RTK (Real-Time Kinematic) and A-GNSS (Assisted GNSS) to help overcome the challenges of urban environments.
Laser scanning is a method that uses laser beams to capture 3D data of objects and surfaces. LiDAR meanwhile, is a particular form of laser scanning that employs laser pulses to determine distances and plot 3D maps called point clouds.
Both laser scanning equipment and LiDAR are used in topographic mapping, environmental surveying and archaeological documentation, forensics and measured building surveys, among others. Laser scanning excels in hard-to-access environments, allowing for precise terrain modelling as well as at scale and often the go to technology for mobile mapping and surveying in combination with GNSS.
Laser scanning has exceptional accuracy (within millimetres) and is therefore a highly useful tool for conducting precision positioning. Its non-intrusive aspect makes it ideal for use in environments where minimal disruption is a requirement, such as in archeological and historical sites. Overall, its efficiency and versatility make it a go-to tool for 3D data acquisition.
One of its main limitations, however, is its cost. This can make it an inaccessible technology for smaller projects and why surveyors may opt to hire laser scanning equipment and associated professional services to ensure everything runs as smoothly as possible.
It also doesn’t always work well in adverse weather conditions such as fog and heavy rain, making its use in outdoor projects more of a challenge.
Now we’ve defined all these technologies, let’s discuss the pros and cons of each:
Total stations provide a high degree of accuracy and precision for localised measurements, while GNSS is more suitable for covering larger areas but has more varying degrees of accuracy.
Laser scanning on the other hand, is capable of capturing detailed 3D data that is both accurate and precise but can struggle in challenging outdoor weather conditions.
GNSS is the most affordable technology, while total stations are also a moderate cost relative to their ROI. As mentioned above, laser scanning equipment is the most expensive piece of equipment, although it does provide the most detailed, high-resolution 3D data.
Ultimately, each method has unique operational costs and conducting a cost analysis is essential before choosing which device (or devices) will benefit a particular project.
If you’re wondering ‘can a combination of total stations, GNSS, and laser scanning provide more comprehensive surveying data?’ – the answer is yes.
With integrated surveying, multiple data collection methods are combined, including total stations, GNSS and laser scanning. Leveraging the strengths of each respective technology results in higher accuracy and more complete coverage in surveying and mapping projects.
Total stations, GNSS and laser scanning technologies all have their strengths and limitations. Total stations provide highly accurate angle and distance measurements in concentrated areas, GNSS can be used to plot points across vast terrains, while laser scanning excels at capturing highly detailed 3D data.
The ideal technology will always be project-specific and depends on your particular survey requirements.
Often, the three are used for different purposes but can be combined for certain projects. This allows for the strengths of each to be used collectively for superior levels of accuracy.
At KOREC Group, we cater to professionals in the surveying, geospatial, engineering and construction industries. We make it our mission to ensure any surveying or mapping task you undertake is done efficiently and effectively, on time and on budget.
Browse our comprehensive collection of total stations, GNSS products and laser scanning equipment to find the right solutions for your needs. Prefer to hire than buy? Our fully supported survey equipment hire service may be what you need, just give us a call to see how we can help you.