What is RTK GPS? Understanding Real-Time Kinematic Positioning
RTK GPS, or Real-Time Kinematic Global Positioning Systems, represents a significant leap in geospatial positioning technology. Known for exceptional accuracy and real-time capabilities, RTK services are becoming a cornerstone in applications ranging from precision agriculture to advanced robotics.
RTK positioning corrects errors in standard satellite data to achieve exceptionally precise positioning data. While building your own RTK system might seem like an exciting challenge, concerns such as accuracy, maintenance, and costly downtime often pose greater risks than rewards. Ultimately, the most dependable and easiest method is to access a professional RTK network like Polaris by Point One Navigation.
RTK is essential for precision industries including agriculture, construction, surveying, robotics, and autonomous vehicles—any application where centimeter-level accuracy makes the difference between success and failure.
How RTK GPS Works: The Technology Behind Centimeter Accuracy
RTK positioning technology relies on communication between the user’s rover and the RTK provider’s base station. The base station is surveyed very precisely so that its position is known to within one or two centimeters.
The base station transmits real-time corrections to the rover receiver, enabling it to cancel out all the major sources of error in its own measurements. The resulting measurements are 100x more precise than normal stand-alone measurements.
The key to RTK’s remarkable precision lies in carrier-phase measurements. Standalone GNSS positioning relies mostly on very accurate, but not very precise, pseudorange measurements of code phase. RTK relies on extremely precise, but ambiguous, RF carrier phase measurements. These carrier-phase measurements provide 100x more precision than the code-phase measurements used in standard GPS.
The heart of RTK is integer carrier phase ambiguity resolution. An RTK-enabled receiver is equipped with sophisticated mathematical algorithms that resolve the ambiguities in the carrier measurements. This unlocks the use of the previously unusable carrier phase and enables position determination to within a couple centimeters.
For users of professional RTK networks like Polaris, these technical complexities happen automatically. You can get set up in five minutes by connecting to a single NTRIP mount point and access centimeter-accurate positioning with lightning-fast convergence times.
Understanding GNSS Signal Errors and Correction Data
GNSS inaccuracies arise from several factors. Signal delays caused by the Earth’s atmosphere, imprecision in satellite orbital data, and the limitations of satellite clock synchronization are some of the primary culprits. These factors can lead to unacceptable positional errors in professional, industrial, or scientific contexts where precision is paramount.
Common error sources include:
- Atmospheric delays: Ionospheric and tropospheric delays cause signals to slow down as they pass through Earth’s atmosphere
- Satellite clock drift: Minor inconsistencies in atomic clocks aboard satellites introduce timing errors
- Orbital inaccuracies: Slight variations in satellite positions from their predicted orbits affect positioning calculations
- Multipath effects: Signals reflecting off surfaces before reaching the receiver create interference
Base stations calculate corrections by comparing the signals they receive to their known precise location. These corrections are then transmitted in the RTCM (Radio Technical Commission for Maritime Services) format, the standard protocol for transmitting correction messages in real-time. Learn more about different GNSS correction methods.
RTK Solution Statuses: Single, Float, and FIX
RTK receivers operate in different states depending on the quality of corrections and signal conditions:
- SINGLE: No corrections are being received. The receiver operates like standard GPS with meter-level accuracy
- FLOAT: Corrections are received but the integer ambiguities have not yet been resolved. Accuracy improves to sub-meter level but hasn’t achieved full RTK precision
- FIX: The receiver has successfully resolved all ambiguities and achieved centimeter-level accuracy. This is the target status for professional applications
Convergence time refers to how long it takes for the system to achieve FIX status after being switched on. RTK is notable for its quick convergence time—typically just seconds with modern systems. This short convergence time means RTK can start providing precise data much faster than traditional systems.
FIX status is required for professional applications needing maximum precision, whether you’re surveying property boundaries, guiding autonomous machinery, or conducting precision agriculture operations.
RTK Corrections: The Data That Makes Precision Possible
RTK corrections are a sophisticated enhancement used across various GNSS, including Global Positioning Systems (GPS), GLONASS, Galileo, and others. While these systems provide location data with reasonable accuracy, factors like atmospheric disturbances and satellite orbital variances can introduce errors. RTK corrections are designed to mitigate these inaccuracies by supplying additional data points.
RTK corrections are real-time data packets transmitted from base stations that account for satellite signal errors. They address ionospheric and tropospheric delays, clock drift, orbital errors, and multipath effects. RTK corrections account for various ambiguities present in navigation constellation signals, which can stem from sources such as satellite orbital errors and atmospheric disturbances. By sharing correctional data in real time, the fixed base station and rover together improve positional accuracy from meter-level to centimeter-level.
These corrections are delivered via the NTRIP (Networked Transport of RTCM via Internet Protocol) protocol over internet connections, radio links, or cellular networks. NTRIP service providers offer various options for accessing correction data, with professional networks like Polaris providing the most reliable and comprehensive coverage.
How Accurate Are RTK Corrections?
The accuracy of RTK is a defining feature that sets it apart from traditional navigation methods. While standard GNSS systems generally deliver meter-level accuracy, RTK enhances this to achieve pinpoint precision. Where a conventional GNSS receiver might offer location accuracy within about three meters, an RTK receiver can refine this to as little as one centimeter—a 100x improvement.
Typical RTK accuracy specifications:
- Horizontal accuracy: 1-3 centimeters under optimal conditions
- Vertical accuracy: 1-3 centimeters depending on signal quality and environmental factors
- Standard GNSS comparison: 3-10 meters with traditional GNSS vs 1-3 centimeters with RTK
Accuracy depends on several factors including baseline distance from the reference station, signal quality, receiver quality, and environmental conditions. Satellite geometry, atmospheric conditions, and the number of visible satellites all play a role in achieving optimal accuracy.
RTK Correction Limitations and Challenges
While RTK location services offer exceptional accuracy, understanding its limitations is important for optimal use. The effectiveness of RTK corrections decreases with distance from reference stations. Additionally, the density of these stations in a given area is crucial for maintaining consistent accuracy.
Signal obstruction presents another challenge. Urban structures, dense foliage, and significant atmospheric conditions can obstruct or degrade GNSS signals, impacting the efficiency of RTK corrections. Buildings, tree canopy, and terrain features can block satellite signals or corrections, reducing accuracy or preventing FIX status.
Advanced RTK providers like Point One Navigation can help users overcome these challenges. The expansive Polaris network ensures broader coverage with a density of over 3,000 base stations, reducing the impact of distance from base stations to deliver centimeter-accurate positioning even in challenging environments such as urban canyons and occluded sky-views.
Types of RTK GPS Systems: Base Station vs. Network RTK
Understanding the different RTK architectures helps users select the appropriate system for their operational needs.
Base Station RTK uses a single, stationary reference station to broadcast corrections. This method is highly effective for localized operations, but its accuracy diminishes as the distance from the base station increases. Single base station setups are ideal for operations within a 10-50km radius, but accuracy degrades with distance from the reference point.
Network RTK involves multiple RTK base stations, creating a larger area containing interconnected stations. This network approach ensures that the RTK corrections are more accurate over a wider area. Multiple interconnected stations provide consistent accuracy across large regions, eliminating single-point-of-failure risks.
It’s important not to think of RTK base stations as standalone units, but rather as pieces of broader, interconnected networks that together offer more expansive coverage. Point One’s Polaris RTK network has global coverage across the US, EU, UK, CA, and AU and boasts the highest overall density of US RTK corrections networks.
RTK networks like Point One Polaris offer scalability, reliability, and professional support that single base station setups cannot match. For businesses requiring consistent performance across multiple sites or large geographic areas, network RTK is the clear choice. Learn more about different network architectures and NTRIP service providers.
RTK corrections are real-time data packets transmitted from base stations that account for satellite signal errors. They address ionospheric and tropospheric delays, clock drift, orbital errors, and multipath effects. RTK corrections account for various ambiguities present in navigation constellation signals, which can stem from sources such as satellite orbital errors and atmospheric disturbances. By sharing correctional data in real time, the fixed base station and rover together improve positional accuracy from meter-level to centimeter-level.
These corrections are delivered via the NTRIP (Networked Transport of RTCM via Internet Protocol) protocol over internet connections, radio links, or cellular networks. NTRIP service providers offer various options for accessing correction data, with professional networks like Polaris providing the most reliable and comprehensive coverage.
How Accurate Are RTK Corrections?
The accuracy of RTK is a defining feature that sets it apart from traditional navigation methods. While standard GNSS systems generally deliver meter-level accuracy, RTK enhances this to achieve pinpoint precision. Where a conventional GNSS receiver might offer location accuracy within about three meters, an RTK receiver can refine this to as little as one centimeter—a 100x improvement.
Typical RTK accuracy specifications:
- Horizontal accuracy: 1-3 centimeters under optimal conditions
- Vertical accuracy: 1-3 centimeters depending on signal quality and environmental factors
- Standard GNSS comparison: 3-10 meters vs 1-3 centimeters with RTK
Accuracy depends on several factors including baseline distance from the reference station, signal quality, receiver quality, and environmental conditions. Satellite geometry, atmospheric conditions, and the number of visible satellites all play a role in achieving optimal accuracy.
RTK Correction Limitations and Challenges
While RTK location services offer exceptional accuracy, understanding its limitations is important for optimal use. The effectiveness of RTK corrections decreases with distance from reference stations. Additionally, the density of these stations in a given area is crucial for maintaining consistent accuracy.
Signal obstruction presents another challenge. Urban structures, dense foliage, and significant atmospheric conditions can obstruct or degrade GNSS signals, impacting the efficiency of RTK corrections. Buildings, tree canopy, and terrain features can block satellite signals or corrections, reducing accuracy or preventing FIX status.
Advanced RTK providers like Point One Navigation can help users overcome these challenges. The expansive Polaris network ensures broader coverage with a density of over 3,000 base stations, reducing the impact of distance from base stations to deliver centimeter-accurate positioning even in challenging environments such as urban canyons and occluded sky-views.
RTK GPS Receivers: Key Features and Capabilities
When selecting RTK GPS hardware, several critical specifications determine performance:
Multi-constellation support enables receivers to track satellites from GPS, GLONASS, Galileo, and BeiDou simultaneously, improving availability and accuracy. More satellites mean better geometry and faster convergence to FIX status.
Update rates typically range from 1-20Hz, with higher rates essential for dynamic applications like drone navigation or autonomous vehicle control. Construction and surveying applications can work with lower update rates, while robotics requires faster positioning updates.
Convergence times separate professional from consumer-grade equipment. Fast convergence—under 5 seconds—minimizes downtime when satellites are temporarily blocked or when powering on equipment.
An RTK-enabled receiver is equipped with sophisticated mathematical routines that resolve the ambiguities in the carrier measurements. Fortunately, when using an RTK service like Point One Polaris, you don’t have to worry about any of these details. You can get set up in five minutes by connecting to a single NTRIP mount point and then access centimeter-accurate positioning with lightning-fast convergence times.
Dual-frequency RTK utilizes two frequency bands. The main benefit of multi-frequency is that it makes it easier to observe the values of the integer carrier phase ambiguities which are at the heart of RTK. By providing more than one independent measurement per satellite, it makes it easier for the user equipment to compute an RTK fix. Dual-frequency receivers provide better ambiguity resolution and availability compared to single-frequency models.
Connectivity options determine how receivers access correction data. NTRIP over internet, radio links, and cellular/LTE connections each have advantages depending on the application environment. For software developers, API availability enables seamless integration into custom applications and workflows.
Getting RTK Corrections: Your Options for Accessing RTCM Data
Users have several options for obtaining RTCM correction data, each with distinct advantages and trade-offs.
Dedicated RTK Networks: Operators can subscribe to dedicated RTK or NTRIP networks like Point One Polaris, which provide wide-area coverage and continuous RTCM data. Commercial RTK networks offer wide-area coverage, 99.99% uptime, and hassle-free 5-minute setup. Professional support ensures you achieve optimal performance even in challenging environments.
Building Your Own Reference Station: Unfortunately, setting up your own RTK system is time consuming, expensive, and requires serious technical expertise. This approach requires significant technical expertise, ongoing maintenance costs, and substantial time investment. Equipment costs, site selection, power and internet connectivity, and regular calibration create ongoing operational burdens. Before committing to a DIY solution, consider whether building your own RTK is really worth it.
Publicly Available Stations: Some organizations offer RTCM data through public CORS (Continuously Operating Reference Stations). While this could be cost-effective, availability and coverage can be variable and rather limited. Public stations often lack guaranteed uptime, technical support, or consistent performance—making them unsuitable for professional applications.
For businesses requiring reliable, professional-grade positioning, commercial networks like Polaris offer the best combination of performance, coverage, and support.
Comparing GNSS Correction Methods: RTK vs. PPP vs. SSR
RTK stands out for providing centimeter-level real-time accuracy using a ground-based reference station network. RTK is ideal for applications requiring high precision and instant correction, such as surveying, construction, and autonomous vehicle navigation.
PPP (Precise Point Positioning) does not rely on a network of ground stations but instead uses precise orbit and clock data from the satellites themselves. However, PPP typically requires a much longer convergence time—rarely faster than 20 minutes and may be up to an hour or more. PPP offers centimeter accuracy with global coverage, making it suitable for non-time-sensitive applications in remote locations.
SSR (State-Space Representation) uses a state-space modeling approach that’s scalable for wide areas and requires specialized receivers. SSR represents a middle ground between RTK and PPP in terms of convergence time and infrastructure requirements.
Each correction method has distinct advantages and suits different operational scenarios. RTK’s real-time, high-precision capabilities make it a preferred choice for many applications that require immediate and highly accurate positional data. Learn more about the detailed comparison of GNSS correction methods.
When to Choose RTK Over PPP or SSR
RTK sets itself apart from other satellite correction technologies by its convergence speed. RTK can converge in as little as about one second or just several seconds in more challenging environments. PPP takes multiple minutes at best. For applications that require immediate and precise location information, the real-time signal calibration afforded by RTK is a must-have.
Choose RTK for real-time applications needing instant centimeter accuracy within network coverage areas. Surveying, construction, autonomous vehicles, and precision agriculture all require the immediate accuracy only RTK provides.
Choose PPP for remote locations without RTK coverage where 20+ minute convergence is acceptable. Marine navigation, remote surveying, and applications where you can wait for convergence benefit from PPP’s global availability.
Choose SSR for wide-area scalability with compatible receivers accepting moderate convergence times. SSR works well for applications requiring better-than-GPS accuracy but not full RTK precision.
Applications of RTK GPS Across Industries
RTK enables new capabilities previously impossible with standard GPS across multiple industries. Applications range from established uses in surveying, agriculture, and construction to emerging technologies like autonomous vehicles and robotics. Real-world benefits include reduced waste, optimized resources, improved safety, and increased automation.
Precision Agriculture and Farming
RTK enables farmers to precisely control agricultural machinery, such as tractors and harvesters, for tasks like planting, spraying, and harvesting. Elevated precision optimizes field operations, including precise application of fertilizers, pesticides, and irrigation, leading to better crop yields, cost savings, and less harm to the environment.
Automated tractor guidance follows preprogrammed paths with centimeter precision, eliminating overlaps and gaps. Variable rate application systems use RTK positioning to adjust fertilizer, seed, and chemical application based on precise field locations. This optimization increases yields while reducing input costs and environmental impact.
Field mapping with centimeter precision enables farmers to track crop performance zones, identify drainage issues, and optimize planting patterns. Reduced overlap in operations saves fuel, fertilizer, and chemicals while protecting the environment. Over time, these savings significantly offset the cost of RTK equipment.
Construction and Site Management
On construction sites, RTK is used extensively for precise positioning and control of heavy machinery. Enabling these pieces of equipment to precisely follow design plans and grades helps minimize rework, reduce material waste, and optimize construction timelines. Additionally, RTK positioning facilitates real-time monitoring of construction progress and enables accurate as-built documentation.
Machine control systems for excavators, graders, and bulldozers use RTK positioning to automatically follow design specifications. Operators see real-time position relative to design plans, eliminating the need for grade stakes and manual measurements. This automation increases productivity while reducing the risk of costly errors.
Site layout and volumetric measurements ensure compliance with specifications and minimize rework. Surveyors stake out building corners, utilities, and site features with confidence. Volumetric calculations for earthwork, stockpiles, and cut-fill operations become faster and more accurate.
Real-time monitoring enables accurate as-built documentation and quality control throughout construction. Project managers track progress against schedules, and inspectors verify compliance with design specifications using the same centimeter-accurate positioning data.
Surveying, Mapping, and GIS
For surveyors and mappers, RTK provides the high level of accuracy required for topographic surveys, GIS (geographical information system) data collection, and large-scale mapping projects.
Topographic surveys, boundary surveys, and GIS data collection achieve survey-grade accuracy without post-processing delays. RTK eliminates the need to return to the office and correct data before beginning analysis. Surveyors verify accuracy in real-time and immediately recollect any questionable points.
Faster data collection with real-time verification improves productivity and project turnaround times. What once required multiple site visits and post-processing can now be completed in a single efficient field session. Seamless integration with CAD/GIS software allows immediate productivity—field data flows directly into design and analysis workflows.
For applications like drone mapping, RTK provides the precise ground control points and direct georeferencing needed for accurate orthophotos and elevation models.
Autonomous Systems and Robotics
Autonomous vehicles require precise and instantaneous positioning data for safety, navigation, and control. RTK enables these vehicles to determine their location relative to their surroundings in real time with centimeter-level accuracy. This level of precision is crucial for ensuring the safety and efficiency of the vehicle, particularly in dynamic environments such as busy city streets or construction sites.
Self-driving cars, agricultural robots, delivery drones, and warehouse automation systems all rely on RTK precision for safe operation. These systems must know their exact position to navigate safely around obstacles, follow designated paths, and perform their intended functions.
Centimeter accuracy enables safe navigation in dynamic environments with moving obstacles. When environments become unexpectedly chaotic or lose control, accurate positioning is essential for making split-second decisions and maintaining safe distances from other objects.
Real-time positioning is critical for split-second decisions in autonomous systems. A delay of even a fraction of a second or an error of a few centimeters can mean the difference between safe operation and collision. Understanding absolute vs. relative navigation helps developers choose the right positioning approach for their autonomous systems.
Additional Industry Applications
RTK GPS provides value across many other sectors:
Damage Prevention: RTK enables equipment operators and workers to precisely locate underground utilities, structures, and other sensitive assets in real time. This helps prevent accidental damage during excavation, drilling, and other ground-disturbing activities, reducing the risk of utility strikes, environmental damage, and costly repairs. Preventing a single utility strike often pays for years of RTK service.
Delivery Logistics: RTK facilitates real-time tracking of delivery vehicles and packages, enabling logistics companies to monitor delivery progress and estimate arrival times with high accuracy. RTK enables efficient routing through urban environments, avoiding traffic congestion, and providing customers with accurate delivery windows. For last-mile delivery and package placement, centimeter accuracy ensures reliable service.
Mining: Volumetric calculations for stockpiles, automated equipment guidance, and fleet management all benefit from RTK positioning. Mining operations use RTK to optimize extraction, track material movement, and improve safety through precise machine control and collision avoidance systems.
Optimizing RTK GPS Performance in the Field
Achieving optimal RTK performance requires attention to several practical considerations:
Maintain clear sky visibility whenever possible. RTK requires line-of-sight to multiple satellites simultaneously. Obstructions like buildings, tree canopy, or terrain features reduce the number of visible satellites and can prevent achieving FIX status. When planning operations, consider satellite visibility and avoid working in heavily obstructed areas when possible.
Minimize baseline distance to the base station for best results. RTK accuracy degrades gradually with distance from the reference station. For single base station setups, stay within 10-50km. Network RTK systems like Polaris maintain accuracy across much larger areas through their dense station coverage.
Avoid electromagnetic interference from power lines, heavy machinery, and radio equipment. High-voltage power lines, generators, motors, and radio transmitters can interfere with GNSS signals and correction data links. Position antennas away from these interference sources when possible.
Proper antenna placement is critical for reliable FIX status. Mount antennas with a clear view of the sky, away from metal surfaces that can cause multipath. Ensure antennas are level and securely mounted to prevent vibration or movement. For mobile applications, antenna placement affects both satellite reception and correction data reception.
Equipment configuration should match your application requirements. Set appropriate update rates, configure the correct coordinate system and datums/epochs, and verify correction data sources. Many RTK performance issues stem from configuration errors rather than equipment limitations.
Precision Agriculture and Farming
RTK enables farmers to precisely control agricultural machinery, such as tractors and harvesters, for tasks like planting, spraying, and harvesting. Elevated precision optimizes field operations, including precise application of fertilizers, pesticides, and irrigation, leading to better crop yields, cost savings, and less harm to the environment.
Automated tractor guidance follows preprogrammed paths with centimeter precision, eliminating overlaps and gaps. Variable rate application systems use RTK positioning to adjust fertilizer, seed, and chemical application based on precise field locations. This optimization increases yields while reducing input costs and environmental impact.
Field mapping with centimeter precision enables farmers to track crop performance zones, identify drainage issues, and optimize planting patterns. Reduced overlap in operations saves fuel, fertilizer, and chemicals while protecting the environment. Over time, these savings significantly offset the cost of RTK equipment.
Construction and Site Management
On construction sites, RTK is used extensively for precise positioning and control of heavy machinery. Enabling these pieces of equipment to precisely follow design plans and grades helps minimize rework, reduce material waste, and optimize construction timelines. Additionally, RTK positioning facilitates real-time monitoring of construction progress and enables accurate as-built documentation.
Machine control systems for excavators, graders, and bulldozers use RTK positioning to automatically follow design specifications. Operators see real-time position relative to design plans, eliminating the need for grade stakes and manual measurements. This automation increases productivity while reducing the risk of costly errors.
Site layout and volumetric measurements ensure compliance with specifications and minimize rework. Surveyors stake out building corners, utilities, and site features with confidence. Volumetric calculations for earthwork, stockpiles, and cut-fill operations become faster and more accurate.
Real-time monitoring enables accurate as-built documentation and quality control throughout construction. Project managers track progress against schedules, and inspectors verify compliance with design specifications using the same centimeter-accurate positioning data.
Surveying, Mapping, and GIS
For surveyors and mappers, RTK provides the high level of accuracy required for topographic surveys, GIS (geographical information system) data collection, and large-scale mapping projects.
Topographic surveys, boundary surveys, and GIS data collection achieve survey-grade accuracy without post-processing delays. RTK eliminates the need to return to the office and correct data before beginning analysis. Surveyors verify accuracy in real-time and immediately recollect any questionable points.
Faster data collection with real-time verification improves productivity and project turnaround times. What once required multiple site visits and post-processing can now be completed in a single efficient field session. Seamless integration with CAD/GIS software allows immediate productivity—field data flows directly into design and analysis workflows.
For applications like drone mapping, RTK provides the precise ground control points and direct georeferencing needed for accurate orthophotos and elevation models.
Autonomous Systems and Robotics
Autonomous vehicles require precise and instantaneous positioning data for safety, navigation, and control. RTK enables these vehicles to determine their location relative to their surroundings in real time with centimeter-level accuracy. This level of precision is crucial for ensuring the safety and efficiency of the vehicle, particularly in dynamic environments such as busy city streets or construction sites.
Self-driving cars, agricultural robots, delivery drones, and warehouse automation systems all rely on RTK precision for safe operation. These systems must know their exact position to navigate safely around obstacles, follow designated paths, and perform their intended functions.
Centimeter accuracy enables safe navigation in dynamic environments with moving obstacles. When environments become unexpectedly chaotic or lose control, accurate positioning is essential for making split-second decisions and maintaining safe distances from other objects.
Real-time positioning is critical for split-second decisions in autonomous systems. A delay of even a fraction of a second or an error of a few centimeters can mean the difference between safe operation and collision. Understanding absolute vs. relative navigation helps developers choose the right positioning approach for their autonomous systems.
Additional Industry Applications
RTK GPS provides value across many other sectors:
Damage Prevention: RTK enables equipment operators and workers to precisely locate underground utilities, structures, and other sensitive assets in real time. This helps prevent accidental damage during excavation, drilling, and other ground-disturbing activities, reducing the risk of utility strikes, environmental damage, and costly repairs. Preventing a single utility strike often pays for years of RTK service.
Delivery Logistics: RTK facilitates real-time tracking of delivery vehicles and packages, enabling logistics companies to monitor delivery progress and estimate arrival times with high accuracy. RTK enables efficient routing through urban environments, avoiding traffic congestion, and providing customers with accurate delivery windows. For last-mile delivery and package placement, centimeter accuracy ensures reliable service.
Mining: Volumetric calculations for stockpiles, automated equipment guidance, and fleet management all benefit from RTK positioning. Mining operations use RTK to optimize extraction, track material movement, and improve safety through precise machine control and collision avoidance systems.
RTK GPS vs. Standard GPS: Understanding the Difference
RTK improves the accuracy of standard GPS data from meter-level to centimeter-level. While GPS is perfectly suitable for some applications, it’s not accurate enough for fields that require high positional precision like surveying, robotics, and autonomous vehicles. RTK-enabled GPS achieves centimeter-level accuracy by using a fixed base station to correct errors in real-time.
Standard GPS provides 3-10 meter accuracy, which is suitable for navigation, general location needs, and recreational applications. Your smartphone uses standard GPS for mapping and directions. Standard GPS works anywhere with a clear view of the sky and requires no subscription or infrastructure.
RTK GPS delivers 1-3 centimeter accuracy, which is required for precision applications like surveying, construction, autonomous systems, and precision agriculture. This 100x improvement in accuracy enables entirely new applications impossible with standard GPS.
The investment in RTK pays off when accuracy directly impacts safety, efficiency, compliance, or product quality. For surveying, construction, and autonomous vehicles, centimeter accuracy it’s essential for professional results. The cost of a single error prevented often exceeds the annual cost of RTK service.
Ready to Achieve Centimeter Accuracy with Point One?
Point One Polaris offers 3,000+ base stations globally with 99.99% uptime and 5-minute setup. Our network provides the density and reliability professional applications demand, with coverage across the US, EU, UK, CA, and AU.
With Point One, you can set up in 5 minutes by connecting to a single NTRIP mount point. After that, you access high-precision GNSS accuracy from 10cm to 1cm at lightning-fast convergence times of less than five seconds. And, this is all at an affordable price point of just $60 per month—a fraction of what building and maintaining your own system would cost.
Polaris by Point One offers exceptional reliability, with 99.99% uptime and secure authentication and transport methods to enhance the dependability of corrections data. When it comes to uptimes, only a professional RTK network such as Polaris will provide the most consistently reliable user-experience.
Our GraphQL API enables seamless integration into your applications and workflows, with professional support for challenging environments. Whether you’re developing autonomous systems, optimizing agricultural operations, or managing construction projects, our team helps you achieve optimal performance.
Skip the hassle and known drawbacks of DIY setups and free providers who can’t guarantee reliability. Take advantage of unparalleled GNSS accuracy and operate confidently with our team of experts by your side.
Contact a Point One expert today to explore how our RTK GPS solutions can transform your precision positioning needs.
FAQs
How is Point One different from standard GNSS?
What is Precision GNSS?
How do I get started using Point One as a developer?
What products already integrate Point One?
What is RTK?
Can I use Polaris corrections with a non-Point One system?
Yes. The Polaris network performs as an RTK network. Non-Point One systems can access the Polaris network using standard NTRIP protocol. Access credentials and documentation are available at app.pointonenav.com.
What is the difference between Polaris and NTRIP corrections?
How do RTK corrections work?
RTK corrections account for various ambiguities present in navigation constellation signals, which can stem from sources such as satellite orbital errors and atmospheric disturbances. By sharing correctional data in real time, the fixed base station and rover together improve positional accuracy from meter-level to centimeter-level.
Let’s get a little more technical:
- Standalone GNSS positioning relies mostly on very accurate–but not very precise–pseudorange measurements of code phase. RTK relies on extremely precise– but ambiguous–RF carrier phase measurements.
- The heart of RTK is integer carrier phase ambiguity resolution. This process turns the ambiguous carrier phase measurements into highly precise measurements of pseudorange, which can be about 100x more precise than the code phase pseudorange measurements–but they are ambiguous to within an integer number of radio carrier wave cycles.
- An RTK-enabled receiver is equipped with a very heavy math routine that’s able to resolve the ambiguities in the carrier measurements. This unlocks the use of the previously unusable carrier phase and enables position determination to within a couple centimeters.
Fortunately, when using an RTK service like Point One Polaris, you don’t have to worry about any of this. You can get set up in five minutes by connecting to a single NTRIP mount point–and then access cm-accurate positioning lighting-fast convergence times.
What is an RTK base station?
An RTK base station is an integral part of any RTK positioning system. In order to correct errors in satellite signal data, RTK positioning requires stationary sites with known, precise locations to serve as reference points. These are called fixed base stations, which send observations to the rover in real time.
It’s important not to think of RTK base stations as standalone units, but rather as pieces of broader, interconnected networks that together offer more expansive coverage. For example, Point One’s Polaris RTK network has global coverage across the US, EU, UK, CA, and AU and boasts the highest overall density of US RTK corrections networks.
This allows the network to offer scalable solutions and ensure high accuracy, even in areas without cellular coverage or in challenging environments in urban canyons.
How accurate is RTK?
RTK offers unparalleled accuracy in positioning at centimeter-level precision. This high level of accuracy is essential for applications where even the slightest deviation can have significant consequences.
Point One’s RTK solutions are engineered to deliver exceptional precision within a few centimeters. This level of accuracy is made possible by Point One’s advanced algorithms, Polaris Network infrastructure, and commitment to using the latest technological advancements in GNSS corrections.
Point One’s RTK system is not just about precise measurements; it’s about providing reliable data you can trust for critical decision-making.
Which applications use RTK?
RTK technology is essential in many areas where exact positioning is needed. In farming, RTK helps guide machinery perfectly for planting and harvesting, boosting crop quality and farm efficiency. Robots in outdoor settings work better with RTK because it helps them navigate through the world with precision.
For preventing damage, especially during construction, RTK is vital for safely locating things like pipes and cables underground. Surveyors and mapmakers rely on RTK for precise measurements of land and buildings, which is important for planning new projects. In construction, RTK is key for correctly setting up sites and ensuring buildings are constructed accurately.
RTK is also crucial for self-driving cars to navigate safely, especially on busy streets. RTK is even changing how deliveries are made by helping to track and direct delivery vehicles, making sure packages get where they’re going on time.
What are GPS correction methods?
Several GPS correction methods, including RTK, PPP, and SSR, improve the accuracy of satellite-based positioning. Each method has its unique approach to correcting GNSS data.
RTK (Real-Time Kinematic) provides real-time corrections, offering centimeter-level accuracy. It’s ideal for applications needing immediate precision, such as autonomous vehicle navigation and precision agriculture. RTK works by comparing the signals from a network of fixed base stations to the satellite data, quickly correcting any discrepancies.
PPP (Precise Point Positioning), on the other hand, doesn’t use a network of base stations. Instead, it uses a single reference station and precise orbit and clock data to offer high accuracy. While PPP can achieve a somewhat similar level of precision to RTK, it takes much longer to converge, making it more suitable for applications where immediate accuracy isn’t critical.
SSR (State Space Representation) is a more advanced method that provides correctional data in a state space format. This technique models the GNSS errors, including satellite orbits and clocks, and atmospheric delays, offering high accuracy over large areas. However, many GNSS receivers aren’t equipped to effectively process all the data provided by SSR, making it difficult to convert into meaningful positions.
Note that discussing GPS, by itself, isn’t standard practice in RTK corrections. Today, unless specifically discussing the USA constellation system, we say “GNSS ” exclusively.
What is the range of RTK corrections?
RTK correction ranges vary depending on the use case. It’s challenging to put a definite number on this question since many variables can affect accuracy, including how much of the sky is visible, the weather, and more.