Whether you are a pro surveyor or are just starting in the business, making the right choice and picking the correct GNSS receiver for your surveying equipment can be a deciding factor for all of your future surveys. Making the right choice will make your results much more accurate, the entire process more streamlined, and make everything much more profitable for you.
We do agree that you should fully understand how GNSS technology works and how it integrates into your equipment. But to buy a suitable type of GNSS receiver for your work, you have to know much more. This is what we are going to explore today as we dive into all the intricacies that will help you make the right kind of choice when picking a receiver.
Understanding GNSS Technology
At this point, if you are a surveying professional, we feel that it is mandatory for you to understand how GNSS technology works. This is mainly because of the technological changes that keep happening in the world of surveying, prompting you to keep up with them if you want to get the most precise results. And when we are talking about accuracy, we do mean millimeter precision requirements, which can make a whole lot of difference, particularly in construction sites where even the smallest discrepancies can create costly mistakes.
GNSS technology includes several satellite constellations that are constantly orbiting our planet, the most popular being GPS (United States), GLONASS (Russia), Galileo (European Union), and BeiDou (China). Every one of these constellations sends out a signal that helps us pinpoint exact locations on Earth. But in order for them to be efficient, at least four satellites are required to pinpoint an exact three-dimensional position on Earth.
The most important factor when it comes to accuracy is a process called trilateration. It helps to measure the time delay between the transmission and reception of signals given off from various satellites, which eventually helps in measuring the distance. The precision of these measurements is actually maintained with the help of accurate timekeeping or an atomic clock found within each of these satellites. Therefore, in order to get accurate positioning, a GNSS system relies on a symbiotic relationship between timing and spatial information.
To say it bluntly, GNSS technology consists of a fusion of timing, space science, and computing, offering a tool that helps all of us on Earth find our way, or better yet, exact coordinates on where we are and where certain objects are positioned.
Key Features to Look for in a GNSS Receiver
With the basics out of the way, it is now time to get into the details about how to pick a good GNSS receiver for your work. Basically, the idea is that if you follow these or simply think about the specifications that we are going to mention, you should end up with a proper receiver for your line of work.
Accuracy and Precision Needs in Surveying
There is no point beating around the bush here - Accuracy is literally the most important factor when it comes to picking GNSS receivers. When your measurements are spot on, your project goes faster, more secure, and you get to finish everything on time. Therefore, you have to make sure that the level of accuracy you are picking goes with the needs of your work.
For example, if you are doing basic land plots, meter-level accuracy works more than well. However, if you are working on certain construction projects, the accuracy needs to be much higher, reaching centimeter or, in some situations, millimeter-level numbers.
Bodies like the ASCE put high importance on high accuracy in surveying to keep the project’s integrity and avoid any unwanted errors. Because of all of this, investing in a high-quality and precise receiver should be your top priority.
Durability for Challenging Field Conditions
Never forget that surveying in the field can end you up in all kinds of situations and weather conditions. Environmental challenges play a massive factor in you getting the right type of measurements, which can be unusable if you don’t record everything right. Not to mention that you may end up damaging your equipment that can’t be easily replaced.
For that reason, we have rugged receivers with IP ratings that have shock absorption capabilities and can ensure accurate readings. There have been numerous occasions where professionals have cited equipment failure or damage in different types of terrains. If you don’t want that to happen to you, you'd better choose wisely and pick a receiver that has a good enough IP rating for the mission you are embarking on.
Satellite Constellation and Correction Service Compatibility
Being able to understand the global navigation system is very important when optimizing any GNSS technology for surveying. GPS, GLONASS, Galileo, and BeiDou are usually the ones that you will be working mostly with, even though there are other ones. More constellations increase satellite availability, making it much more accurate for you pinpoint exact locations. Therefore, picking multi-constellation GNSS receivers will help to gain improved accuracy even in difficult environments.
But if you combine GNSS with real-time correction (RTK) services, the accuracy increases further. RTK can help to correct satellite signal errors in real time, making things as pinpoint as possible for you. However, service quality will still depend on the surrounding infrastructure, which can make things a bit challenging in remote areas.
Critical Technical Specifications
Some of the most important technical specs that you have to keep an eye out for is multi-frequency support. It can help minimize eros and enhance signal reliability. When GNSS receivers have access to multiple frequencies, it can help to alleviate multipath effects and also ionospheric delays. This type of capability is of great help if you are working in urban areas where there are many obstructions to the signal, allowing you to collect data without any added problems.
Another piece of tech that you can combine here is again RTK positioning. It can offer you centimeter-level accuracy, which can be crucial for precision surveying. Even if you are facing environmental limitations, RTK compatibility helps to improve efficiency. Therefore, if precision is a non-negotiable for the project you are doing, adding RTK will drastically improve the efficiency of your toolset, allowing you to overcome obstacles or problems that might appear in the field.
Integration with Surveying Workflows
Software compatibility can interrupt your GNSS workflow more than you think. You have to ensure that the integration of software with your surveying equipment is done perfectly so you ensure smooth operation and data management. For instance, for data sharing, you are mostly going to be using formats like DXF and GIS, which makes things much more flexible for surveyors and allows easier analysis. Therefore, you are going to want to incorporate programs like AutoCAD and ArcGIS, which allow usage with different types of data.
You are also going to have to think about optimizing field-to-office data transfer. One of the best ways to do that is via different mobile apps and cloud storage solutions. It helps you to move data without any problems or shortcomings, enhancing productivity at the same time. But you also have to think about tool efficiency and connectivity issues in remote areas. If you manage to solve all of these problems before heading out to the field, you will be saving a lot of time and effort, which may not be the case with traditional methods.
10 Questions to Ask Before You Buy
When picking the right GNSS receiver, we came up with ten burning questions that you should ask yourself first that will help you determine the exact tool you need. It basically works by you going through all of them and eliminating certain factors while concentrating on the ones you need, eventually helping you come up with the results and a piece of equipment that will do the job for you. These are…
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What GNSS constellations does it track?
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How fast does it achieve RTK fix?
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What’s the real-world accuracy?
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Does it support multi-frequency tracking?
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What’s the actual battery life?
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How rugged is it?
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Is it compatible with my existing desktop CAD and data collection software?
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What connectivity options are included?
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What warranty and support plans are available?
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What’s the total cost of ownership?
Types of GNSS Receivers
There is no one-size-fits-all GNSS receiver, as there are different types of them with each one having specific characteristics. Of course, every one of them is good for a specific situation, making it particularly useful based on the type of work you are planning on doing. More so than that, each different type of receiver is tailored to accommodate a different sector, offering specific functionality based on its strong characteristics.
Here are the most common types of GNSS receivers and how to distinguish between them:
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Single-Frequency Receivers: You will find these receivers mostly used in consumer-grade applications. They interact with only a single frequency from the satellite constellations, making them ideal for basic navigation and mapping tasks. They offer enough accuracy for general activities, but are not enough if you are planning on using them for something far more serious.
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Multi-Frequency Receivers: These types of receivers are designed for high-precision tasks. They can process signals from more than one frequency, helping them to improve their accuracy. Besides surveying, you will find them used in agriculture and even the aerospace industry. Since they use multiple frequencies, they have the ability to correct signal distortions caused by atmospheric conditions, allowing them to gain sub-meter to centimeter level accuracy.
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Augmented GNSS Receivers: Augmented systems use added info from ground-based or space-based systems to help improve accuracy and positioning. Aviation landing systems and critical surveying operations mostly rely on augmented GNSS receivers, as they can help to achieve pinpoint accuracy by correcting a GNSS signal with the help of supplementary data.
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Software-Defined Radios (SDR) GNSS Receivers: SDR GNSS receivers use additional software to process signals, which helps them adapt to new GNSS signals without any hardware modifications. Researchers and developers are usually the ones who use this type of technology, as it helps them in facilitating their experiments with new algorithms and signal processing techniques.
Conclusion
There you have it, as you can see, picking a GNSS receiver is not an easy thing to do, and it does require some additional knowledge and professionalism to really pick a correct one. Surveyors and professionals might already be used to doing this on the fly, but if you are just beginning, some thoughtful research might be in order. Be sure to determine the accuracy you need, RTK possibilities, durability based on the challenges you might be facing in the field, and satellite constellations that are available. Of course, this is only the start, as you will soon be diving into something very complex, but with experience and research, you will be able to make the right choice in the end.
FAQ
For further info on GNSS receivers, you can go through some additional questions below.
What are the real-time correction services available for GNSS receivers?
Real-time correction services improve GNSS accuracy by compensating for satellite, atmospheric, and clock errors, with the most common being RTK (Real-Time Kinematic), which uses corrections from a local base station or GNSS network; Network RTK (NRTK), which provides corrections from multiple reference stations via the internet; SBAS services such as EGNOS or WAAS for meter-level accuracy; and Precise Point Positioning (PPP) services, which use global correction data to deliver decimeter- to centimeter-level accuracy without a local base station.
Why is accuracy important in surveying?
Accuracy is critical in surveying because even small positional errors can lead to boundary disputes, construction misalignments, costly rework, legal issues, and safety risks, while high-accuracy measurements ensure reliable mapping, precise layout, correct volume calculations, and compliance with engineering, cadastral, and infrastructure standards.
How do GNSS receivers work?
GNSS receivers work by simultaneously tracking signals from multiple navigation satellites, measuring the time it takes for each signal to reach the receiver, and using this information to calculate precise positions through trilateration, with accuracy significantly enhanced when real-time or post-processed correction data is applied.
What is a GNSS receiver?
A GNSS receiver is a satellite-based positioning device used in surveying to determine precise geographic coordinates by receiving signals from global navigation satellite systems such as GPS, GLONASS, Galileo, and BeiDou.
Why are GNSS receivers important?
GNSS receivers are important because they enable fast, accurate, and efficient positioning and data collection in surveying, reducing field time, minimizing human error, supporting real-time decision-making, and allowing surveyors to perform complex tasks such as topographic mapping, construction staking, and monitoring with high reliability.
