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RTK correction services and NTRIP Casters in United States
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✈︎ ArduSimple delivers to customers in the USA in 2-4 business days!
If you’re in the United States of America and need centimeter-level position accuracy, you’ll need access to an RTK correction service or NTRIP Caster via the internet. Below are the main options available, explained in a simple way so you can quickly choose what fits your project.
In order to access real-time services and obtain NTRIP credentials, you need to register on the website or send them an email. The registration process is not always very user-friendly, so it might take some effort. If you run into any difficulties, contact us – we’re happy to assist.
National RTK network in the USA
Many countries around the world have established their own National RTK Networks to support various high-precision GNSS applications within their borders. As far as we know, the United States of America does not have a national RTK network that operates across the entire country. However, we have identified some RTK services that operate in specific states.
If you know any RTK network in the USA which is not in the list, please contact us. Your input will help us provide better resources for the surveying community.
Most local and regional networks base their corrections on the reginal NAD83. Keep in mind that the specific NAD83 depends on your location: the North American Plate uses NAD83(2011), the Pacific Plate uses NAD83(PA11), and the Mariana Plate uses NAD83(MA11).
Note that the US National Geodetic Survey is modernizing the national coordinate system by replacing the current NAD83 with four new coordinate systems and new vertical datum. Beta releases of various NSRS 2022 will roll out during 2026, with the official launch planned for 2027.
If you want to compare your receiver’s reported position with Google Maps, note that NAD83 is not identical to the global WGS84 coordinate system used by Google Maps. Because Google Maps is aligned to a global WGS84, there is typically a 50–80 cm offset between local NAD83-based coordinates and global WGS84 coordinates. For measurements intended to match Google Maps more closely, it is often easier to use an RTK correction service that operates in aglobal coordinate system (you will find them further down) rather than a local one.
Free international RTK correction services in the United States of America
These free services are a good starting point, especially if you want to test or keep costs low. However, they come with some limitations, mainly in terms of reliability, accuracy, or coverage. You can use them to achieve centimeter-level accuracy in the USA if you are lucky to have a base station close to you (remember that RTK only works up to 35-50 km).
| Service | Type | Access | Accuracy | Coordinate System |
|---|---|---|---|---|
| RTK2GO | Free global community-based network | RTK2GO coverage map ("View all" on the top right) Register | Network without quality of the service ✔ Great if you only need pass-to-pass accuracy and you don't need to compare measurements taken by other systems or with local maps. Community-based RTK networks are the cheapest way to go, but are maintained by individuals, so quality depends on the area. ✖ Not suitable for surveying calibrated applications. | Not standardized |
| IGS | Free global service | IGS coverage map Register | High quality service with absolute accuracy but low density of base stations. ✔ It is more reliable than community networks. You can use it to achieve centimeter-level accuracy if you are lucky to have a base station close to you. ✖ Limited coverage and low base station density. Check the coverage map to see if you have a base station nearby (remember that RTK only works up to 35-50 km). | Global ITRF |
| Earthscope (previosly UNAVCO) | Free (for non-commercial use only) global service | Earthscope coverage map Register | Typically ITRF, but bases are in reginal frames |
We have prepared a tutorial How to connect GNSS/RTK receiver to a NTRIP correction service via PC.
Paid international correction services in the USA
If no nearby base station is available in free networks, if you require guaranteed service quality, or if your project demands reliable absolute accuracy aligned with a consistent reference frame, consider the following paid correction services in United States:
| Service | Type | Access | Accuracy | Coordinate System |
|---|---|---|---|---|
| u-blox PointPerfect Flex | Paid service: from $5.90/month (up to 100 hours of use). Try it for free with PointPerfect 30-Day Trial (no payment needed). | PointPerfect coverage map and free trial. To help you register to the service, we prepared a tutorial. | 1 centimeter RTK, 2-4 centimeter accuracy RTK-SSR | Global ITRF |
| Swift Navigation Skylark | Paid service: from $69/month (1 cm RTK) or $29/month (sub-decimeter RTK-SSR, unlimited use). Try it for free with the Skylark 6-Month Trial (no payment required). | Skylark coverage map and free trial. To help you started, we prepared a tutorial. | 1 centimeter RTK accuracy; sub decimeter RTK-SSR | Global ITRF |
Set up your own correction service
If you didn’t find anything nearby you or you simply would like to become independent from any service, check out our ready-to-use all-band, full-constellation RTK Base Station. Setup is simple—just follow the User Guide: RTK Base station.
Galileo HAS: a free option but lower accuracy compared to RTK
If 40 cm accuracy is sufficient for your project, you can try Galileo HAS, a free, globally available correction service.
- It works without the internet, NTRIP, or a local base station. While not as precise as RTK, it can still improve positioning accuracy. However, it takes up to 5 minutes to reach full accuracy, compared to just a few seconds with NTRIP.
- Galileo HAS uses the GTRF reference frame, which is closely aligned with ITRF global coordinate system (differences are typically below 3 cm). This means you will usually have to do a conversion to local coordinate system to compare measurements with other maps.
- Not all RTK boards are compatible with Galileo HAS. Here are GNSS RTK receivers that fully support Galileo HAS:
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- RTK3B Boards
simpleRTK3B Micro Unicore
From 276,00€ This product has multiple variants. The options may be chosen on the product page
Post-processing (PPK) in the US
If you are looking for post-processing (PPK) instead of RTK in United States, contact us — we’ll help you find the most appropriate service for your project.
