No matter if you are working as a land surveyor, particularly in drone surveying, GIS mapping, or even agriculture, you have probably heard about the term RTK being tossed around many times. If you haven’t, then you are seriously lagging behind. RTK technology has become the industry standard for modern surveying, especially for professionals who rely on accurate GNSS measurements in real time. 

RTK, or Real Time Kinematic, is a satellite positioning technology that can help improve the accuracy of standard GPS/GNSS receivers tenfold. For comparison, your standard GPS positioning can help you get the accuracy to the meter level. However, when it comes to RTK technology, it can help reduce positioning errors down to a few centimeters. Those who require this level of precision usually dabble in machine control, land surveying, construction layouts, and drone mapping, where even the smallest error can make a huge difference. 

But if you really want to improve the precision level of your RTK equipment, the best way to do so is with an RTK licence. The primary benefit that you get with one is pinpoint accuracy in various locations. This is particularly beneficial for drone pilots as it helps you to get pinpoint accuracy for your UAV. If this is the first time you’ve heard about RTK licences, then you should stay on this page to learn how to acquire one and what the actual benefits of obtaining it. 

What is RTK?

To determine why or whether you need an RTK licence, you first need to understand how RTK itself works. RTK refers to the process of calculating highly accurate positions in real time while you move your receiver during a survey on a site. Compared to standard GPS systems that rely solely on satellite signals, RTK systems receive constant correction data from an RTK network or a reference station. The part that says “real-time” is key, as it means that you are receiving instant measurements the second they are being calculated, while the part that says “kinematic” means that you can move your RTK receiver around and still maintain accurate positioning. 

Compared to standard GPS, RTK is capable of providing much higher accuracy. Your standard GPS receivers calculate the travel time of a signal sent from various satellites positioned around Earth, which works more than well for navigation. But several factors reduce accuracy, which are very important for most surveying tasks that we have today. Satellite signals are affected by a variety of things, but mostly include atmospheric disturbances, signal reflections from buildings, timing inaccuracies, and satellite orbit errors. This kind of accuracy results in meter-level positioning, which, as you can guess, is not enough for jobs like property boundaries or guiding construction machinery, where you need centimeter-level positioning.  

This is where RTK is the solution to the problem, as it can correct satellite signal errors and do it in real time. An RTK GNSS system usually consists of a base station and a rover receiver. The base station stands at a fixed point with known coordinates, and because its coordinates are already known, it can compare the satellite position with its own position and calculate the errors that might affect GNSS signals. The corrected values are transmitted to the rover, which it applies immediately, resulting in highly accurate positioning. 

What is an RTK License Used for?

Now that you know more about RTK technology and what its benefits are, we get back to RTK licences and how they are used. With an RTK licence, you basically get a subscription to a network of permanent reference stations that stream corrections and deliver them to your rover via NTRIP.

Venturing into the field, many surveyors rely on single network dependency, which is a high-risk that you shouldn't be taking. If one correction provider degrades, the only choice you have is to stop working, despite having the entire crew and equipment primed and ready. An RTK premium licence will allow you to continue working as it draws corrections from independent sources instead of relying only on a single one. So if one source fails, corrections will still continue to arrive, allowing you to continue your work without any interruptions. 

And don’t worry about it stopping; the uptime of RTK licences has been at 99.98% since 2018 when the technology became more widespread, and it even gives you 1.5 cm accuracy at all times. 

How do Network RTK Corrections Work?

The main part of acquiring an RTK licence is that you don’t need to have your own base station with you. Not needing one saves you time, effort, and money; you don’t need to pack an additional piece of equipment with you, and you are not required to buy one to include in your setup. The correction network will do all the work for you and will do it continuously without stopping. 

Here is how things usually go: 

  1. Continuous Reference Station Observation

A network of permanent, fixed-position GNSS base stations, in this case 7,500 stations, continuously tracks satellite signals from multiple GNSS constellations (GPS, GLONASS, Galileo, and BeiDou). Each station logs raw carrier-phase and pseudorange data around the clock, providing the redundant, multi-constellation observation set required for network-wide error modelling.

  1. Network-Wide Error Modelling

Rather than correcting for errors at a single site, the processing engine (e.g., Geo++ GNSMART II) analyzes data from all reference stations simultaneously to model spatially correlated error sources across the entire network. This includes ionospheric delay, tropospheric delay, and satellite orbit errors. Because the model is interpolated across the network's geometry, it remains accurate even for rovers positioned between reference stations, not just near a single fixed base.

  1. Correction Delivery via NTRIP

The rover establishes a connection to the correction service using an NTRIP account, typically over a cellular data connection. The network computes a localized correction stream tailored to the rover's approximate position (e.g., using VRS, MAX, or i-MAX formats) and transmits it as standard RTCM 3.x messages, ensuring compatibility across GNSS receiver brands.

  1. Ambiguity Resolution and Position Fix

The rover's receiver combines its own raw satellite observations with the incoming network corrections to resolve carrier-phase integer ambiguities, typically within seconds under good sky visibility. Once fixed, the receiver reports a position accurate to better than 1.5 cm, referenced to a certified geodetic reference frame, meeting survey-grade precision standards.

RTK Network Coverage and Redundancy

Licensed RTK network services are not limited to one infrastructure; they can actually be turned on through a reseller or a different type of end-user. The idea is that with a single account, you get coverage in more than 35 countries in the world. The best part about it is that you can plan ahead by checking the availability of networks through a live map. That way, you are certain that you are venturing into the field with the aim of finishing the job that you’ve planned. 

  • Redundant, Independent Correction Sources: The network draws on multiple, independent correction services with no shared points of failure. If one source degrades or drops out, it does not cascade to the others; the rover can fail over without losing service continuity. This is a meaningful distinction from traditional single-base RTK, where a single station outage means a full loss of corrections.

  • Multi-Level Switching (User, Reseller, Solution): Corrections can be reassigned at three levels of granularity: Per device (end-user level), an individual rover can be switched to a different correction source without affecting the rest of the fleet. Per account (reseller level), a reseller can manage source allocation across their client base. Across a deployment (solution level), an entire project or organization can be migrated to a different correction provider in bulk, useful for large-scale rollouts or contract changes.

  • Extensive Coverage with Single-Account Access: Coverage spans 35+ countries under one unified account, eliminating the need to provision separate credentials or subscriptions per region for multi-national or cross-border survey operations.

  • Verifiable Deliverability: Correct delivery is logged on a per-session basis, creating an auditable record of signal receipt and quality. This is particularly valuable for legal or contractual disputes over measurement accuracy, since the delivery record can substantiate (or challenge) the integrity of a given RTK fix.

  • Live Coverage Heatmaps: Real-time service availability can be checked via a live coverage map before mobilization, allowing crews to confirm signal reliability at the job site before deployment rather than discovering gaps after arrival, reducing wasted site visits and downtime.

Advantages and Limitations of RTK

RTK is an excellent choice, in fact, perhaps the best one for a variety of surveying work. But it does come with its flaws, which you do have to consider before making the final choice of whether to choose it or not. The biggest advantage, of course, accuracy RTK positioning helps to drastically reduce positioning errors, making your work productive and effective at the same time. Also, since the corrections are applied at the same time, it helps you deliver faster. 

Modern RTK receivers, compared to older systems, are much more reliable, faster, and much easier to use. The fact that it uses better GNSS antennas, multi-frequency GNSS tracking, and advanced correction algorithms makes this technology stable even in challenging environments. Finally, as RTK networks keep expanding across the globe, it will make the technology more affordable to use for anyone who happens to need it. 

Having said all of that, there are still some limitations that you have to be aware of. The system is dependent on having a stable correction signal and satellite visibility. It does not thrive in dense forests, mountains, urban environments, and areas with poor mobile reception, which results in reduced performance. 

Distance from the base station may also affect accuracy. These systems tend to work better within a distance of 10 to 20 kilometres from a reference station. Luckily, the technology keeps improving, and even these challenges are easily surmounted as time goes by. 

FAQ 

For a brief overview, here are some additional answers to more questions about RTK licences. 

How much does an RTK subscription cost?

Depending on the provider, accuracy, and industry application, RTK correction services usually cost between $40 and $100 per month, or somewhere in the vicinity of $400 to $1,200 per year. If you are a professional who needs this type of service full-time, there are multi-year plans that can reduce costs to even $32 per month. 

Does RTK require a subscription?

Generally speaking, no, you don’t need a subscription as long as you have a local base station or public correction networks. But if you want to opt for an RTK network licence in specific areas or for broader coverage, that service is paid as it unlocks more specific areas for you to survey, provides you with centimeter-level accuracy, and does not necessarily require you to have a base station. 

Does RTK require GPS?

Yes, it does. RTK networks do require GPS, or any other satellite navigation (GNSS) system. This is because RTK is not a standalone positioning system; it is there to provide corrections and upgrade the signal that you get from GNSS satellites, allowing you to improve accuracy from meter-level to centimeter-level. 

Can I add RTK to my drone?

Yes, you can, but it will depend entirely on the model of your drone. For instance, you cannot easily add any RTK hardware to standard consumer-grade drones. What you can do is use an RTK/NTRIP app if your drone is capable of supporting it and, in a way, create a DIY drone for surveying purposes. But if you are a professional surveyor, you can get a drone that is specifically designed to support RTK hardware and any other components that you might need for your standard work.