Should you set up your own RTK base station (Base)? Comparing NTRIP use and costs

Table of Contents

• What is an RTK base station?

• What is NTRIP?

• Advantages and disadvantages of setting up your own RTK base station

• Advantages and disadvantages of using NTRIP

• Cost comparison between RTK base stations and NTRIP

• Which should you choose?

• Simple surveying and using LRTK

• FAQ

In recent years, the introduction of high-precision positioning technology called RTK (Real Time Kinematic) has progressed in construction and surveying fields. Centimeter-level positioning accuracy achieved by RTK brings benefits to worksites that standalone GPS positioning could not provide, helping to streamline surveying tasks and enabling autonomous operation of construction machinery. On the other hand, many engineers face the dilemma of whether to install and operate their own “base station” required for RTK operation or to use an Internet-based network RTK service (NTRIP). This article explains the basics and roles of an RTK base station and compares the costs, advantages, and disadvantages of running your own base station versus using an NTRIP service. I hope this helps you decide which option best suits your company’s needs.

What is an RTK base station?

An RTK base station (reference station) is a fixed station that serves as the reference for error corrections in RTK positioning. RTK positioning typically uses two GNSS receivers simultaneously: a base station and a rover (mobile station). The base station is installed at a point whose coordinates are already known accurately; by comparing the positioning results of GNSS satellite signals it receives with the known coordinates, it calculates the errors. It then sends that correction data to the rover in real time. By applying the correction information received from the base station to its own GNSS positioning, the rover can reduce positioning errors from several meters to a few centimeters. In other words, the base station functions as the reference point that enables the rover to obtain high-precision positions.

Traditionally, dedicated radios such as UHF bands have been used to transmit correction data from the base station to the rover. For short distances, radios communicate directly with each other and can deliver differential data in real time. Recently, however, networked RTK that distributes correction information via the Internet has become widespread. This uses a mechanism called NTRIP (described below), allowing base station data to be sent and received without physical dedicated radios.

What is NTRIP?

NTRIP (Networked Transport of RTCM via Internet Protocol) is a protocol for distributing GNSS correction data over the Internet. Simply put, it’s a mechanism for receiving reference station data from remote locations via mobile networks and the like. If an RTK receiver (rover) can connect to the Internet via mobile data or Wi‑Fi, it can obtain real-time correction information from an NTRIP-compatible distribution server (NTRIP caster).

In Japan, there are networks of geodetic control points maintained by the Geospatial Information Authority (about 1,300 stations) and GNSS reference station networks maintained by private companies, and real-time correction services that leverage these networks are available. For example, SoftBank’s “ichimill” has deployed more than 3,300 proprietary reference stations nationwide and distributes centimeter-level correction information to subscribers. Using NTRIP, users can achieve high-precision RTK positioning without installing their own base stations. However, use requires a communications environment; the worksite must be within mobile coverage. In areas without signal, the traditional method of using your own base station plus radio communication to exchange correction data remains effective.

From the next sections, let’s look at the respective advantages, disadvantages, and cost differences between setting up your own RTK base station and using an NTRIP service.

Advantages and disadvantages of setting up your own RTK base station

Advantages

• Lower running costs: Once you have installed the base station equipment, you do not incur monthly fees to use correction data. Over the long term, running your own base station can be more economical than continuously paying for a service.

• Can operate multiple rovers simultaneously: One in-house base station can share the same correction data among several rovers. For example, on sites where multiple workers use multiple GNSS receivers or construction machines, everyone can use corrections from a single base station via radio or network distribution without needing separate contracts for each device.

• Operable even outside mobile coverage: In mountainous areas, remote islands, or offshore sites where mobile signals do not reach, real-time positioning is possible by linking your own base station and rovers via radio. Because it does not rely on external services, you can achieve high-precision positioning regardless of location.

• No service dependency risk: By managing the base station in-house, you can control risks such as stoppage of correction information or service suspension. You gain the reassurance of operating without being affected by external operators’ system maintenance or failures.

Disadvantages

• High initial cost: Purchasing high-precision GNSS receivers and antennas for base stations is not cheap, and installation work also incurs costs. Equipment installation requires placing antennas outdoors at high, unobstructed locations, preparing mounting poles and brackets, and measures for lightning protection and waterproofing, so construction demands a lump-sum investment. For small and medium-sized businesses, this initial burden can be a major hurdle.

• Maintenance and management burden: Running your own base station involves equipment maintenance, regular operation checks, firmware updates, and possibly radio station permit applications/renewals, creating management tasks. You must handle breakdown responses and theft/damage prevention measures yourself, which becomes a personnel burden.

• Limited coverage area: The effective range for base station correction data is generally said to be within a radius of several km to a dozen or so km from the base station. A fixed base station cannot serve sites that are far away, so you may need to add or relocate base stations for new sites. This is impractical if your sites move widely across large areas.

• Requirements for environment and risk management: High-precision base station operation typically requires antenna installation in a location with a wide open view of the sky and an environment free from sources of radio interference. You also need measures to protect equipment from lightning, strong winds, and extreme temperature changes. Your company bears the responsibility for securing installation environments and risk management.

Advantages and disadvantages of using NTRIP

Advantages

• Low initial barrier: Using a network RTK service eliminates the need to prepare expensive base station equipment yourself. As long as you have a rover GNSS receiver, you can immediately receive correction information after contracting. The ease of introduction is a major benefit.

• Usable almost anywhere nationwide: Private RTK correction services use mobile networks and cover almost all of Japan. Even if your worksites are scattered, you don’t need to install new base stations at each site, and you can obtain consistent positioning accuracy across regions. It’s suitable when you want to cover wide areas flexibly.

• Maintain accuracy over long distances: Corrections based on multiple reference stations (e.g., VRS method) can maintain stable accuracy even at locations tens of kilometers away where a single base station’s accuracy would typically decrease. The ability to suppress errors at remote sites is a unique advantage of networked systems.

• Less operational burden: Service providers generate and distribute correction information, so users can use the system without handling complex technical operations. Maintenance and calibration of base stations are unnecessary, reducing daily operational workload.

Disadvantages

• Ongoing usage fees: Network services require monthly or annual subscription fees. Fees are often a few thousand yen and relatively inexpensive, but cumulative costs over long use are not negligible. For example, a 5,000 yen monthly plan amounts to 300,000 yen over five years, which can rival equipment purchase costs.

• Costs increase as number of users grows: When multiple devices use RTK, typically each device requires a separate service contract. While one in-house base station can serve multiple rovers, network services incur per-device subscription fees (some major providers offer multi-ID discount plans, but costs still generally increase proportionally with device count).

• Dependence on communications environment: Since receiving correction data always requires a communications line, services cannot be used where mobile signals do not reach. Network RTK will not function in tunnels or deep mountains; in those cases, the traditional approach of in-house base station plus radio is necessary.

• Dependent on service provider’s conditions: Correction data are provided by service operators, so you are affected by their system maintenance or temporary outages. The format and content of distributed data also depend on the service, limiting detailed in-house control or customization. However, for typical positioning tasks, such restrictions rarely pose problems.

Cost comparison between RTK base stations and NTRIP

As mentioned above, in-house base station operation and network service use have very different cost structures. Comparing major items yields the following:

From this comparison, the cost benefits of operating RTK vary by usage pattern. If you want to minimize initial investment and use services only when needed, networked RTK is advantageous. However, if you will use RTK continuously over many years, setting up your own base station may ultimately be cheaper.

Which should you choose?

Based on the above, whether an in-house base station or an NTRIP service is more suitable depends on the user’s situation. Generally, it is advisable to first consider a network RTK service because it is easy to start with. When introducing RTK surveying for the first time or when projects are spread across many sites, NTRIP use is realistic and cost-effective because there is no need to prepare base station equipment. For small businesses or short-term projects, network services that allow low-cost, time-limited contracts are an attractive choice.

On the other hand, if your company has large-scale construction sites that remain in the same area for long periods, or if you need RTK in environments far from communications infrastructure such as mountainous areas or remote islands, setting up your own base station becomes meaningful. Although the initial investment is large, there is no additional cost when operating multiple machines simultaneously, and you can perform independent positioning even outside mobile coverage. For long-term use on large projects, the initial cost can be recouped with substantial benefits.

In summary, a useful guideline is: if you want flexible wide-area use and to keep initial costs low, choose NTRIP; if you will use RTK continuously in a fixed area or work in areas with unstable communications, set up your own base station. That said, network services are rapidly improving, and in many cases you can operate without an in-house base station. It is wise to first check available correction services and consider an in-house base station only if necessary.

Simple surveying and using LRTK

“I don’t want the hassle of setting up my own base station; I want to use RTK more easily.” A solution to that need is the recently introduced LRTK series. LRTK is a small GNSS receiver device developed to make RTK positioning more accessible, enabling simple centimeter-accuracy positioning by linking with a smartphone or tablet. For example, a product called “LRTK Phone” is an ultra-thin dedicated GNSS unit weighing approximately 125 g and about 13 mm (0.51 in) thick that you simply attach to the back of an iPhone to instantly turn the smartphone into a versatile surveying instrument capable of high-precision positioning. No complicated operation is required; by launching the dedicated app and pressing a button, you can perform surveying of reference points and staking-out tasks, making it easy to use even for non-specialist surveyors.

LRTK devices can obtain real-time correction information via the smartphone’s communications, so they can connect to existing network RTK services such as NTRIP and perform high-precision standalone positioning. At the same time, LRTK devices can be combined to build a simple in-house base station. For example, with two LRTK devices, you can place one at a known point on site as a mini base station and use the other as a rover, enabling conventional RTK surveying even at sites outside mobile coverage or in areas not covered by services. In other words, LRTK allows you to use both “the convenience of network RTK services” and “the independence of in-house base station operation” as the situation requires.

Furthermore, LRTK is a multi-GNSS, multi-frequency receiver that supports Japan’s quasi-zenith satellite “Michibiki” centimeter-class augmentation service (CLAS). Because it can receive CLAS signals, it can maintain high-precision positioning from satellite-based corrections even where mobile communications do not reach. Functionally, LRTK features a high-performance RTK engine that quickly obtains a fixed solution and automatic pole-tilt compensation, thoroughly pursuing ease of use on site. The dedicated LRTK app allows intuitive switching of correction input sources (network or CLAS) and positioning modes, so anyone can operate it without confusion.

By leveraging LRTK, centimeter positioning that previously required large equipment and specialized knowledge can be achieved with a simple “one smartphone + small device” configuration. If each field worker can carry their own high-precision positioning tool, surveying and construction management workflows can be dramatically improved. Since the introduction cost is lower than traditional surveying instruments, small and medium-sized companies can more easily adopt it. If you are interested in simple surveying with RTK, check LRTK details—you may be able to realize a new surveying style on your site that combines ease and high precision.

FAQ

Q: What do I need to install my own RTK base station? A: You need a high-precision GNSS receiver and antenna for the base station, a secured installation site (stable location with good visibility), power supply, and communications environment. You should also prepare mounting poles and waterproof cases for the antenna, as well as lightning protection. If you plan to distribute correction data via communications, you will need an Internet connection or radios and, if required, radio station permits.

Q: How can I use correction services via NTRIP? A: If you have an NTRIP-compatible RTK receiver (rover) and an Internet connection, you can use NTRIP. First, contract with a private or public correction service provider and configure the receiver or positioning app with the provided NTRIP server connection information (URL, port, user ID, etc.). Then, at the site, connect the receiver to the Internet via smartphone tethering or an embedded SIM, and you can receive real-time correction data and start high-precision positioning.

Q: How far apart can the base station and rover be and still achieve RTK positioning? A: In general, positioning accuracy gradually decreases as the distance from the base station increases. Typical RTK maintains centimeter-level accuracy when the distance between base station and rover is within about 10–20 km, but errors tend to increase beyond that. Network RTK using multiple base stations can sometimes maintain centimeter-level accuracy even 50 km away. However, bear in mind that very large distances can make it difficult to obtain an immediate high-precision fix.

Q: Is RTK positioning impossible in areas without mobile coverage? A: RTK positioning is possible in communication-free areas depending on the method. If you set up your own base station and exchange correction data with rovers via radio, you can perform real-time positioning without the Internet. Also, in Japan, satellite-based correction services such as Michibiki’s CLAS can provide corrections directly from satellites (a compatible receiver is required). For example, LRTK terminals support CLAS, so they can maintain positioning accuracy using satellite augmentation even in mountainous areas.

Q: What is LRTK? A: LRTK is the name of a series of compact RTK positioning devices developed by Refixia Co. It is an ultra-light GNSS receiver that attaches to a smartphone and enables centimeter-level positioning by leveraging network RTK and satellite augmentation. It allows users to obtain and share high-precision coordinates easily without specialized surveying instruments, offering a solution with strong potential to transform simple surveying and construction management workflows.