Tips to Increase RTK Fix Rate: Settings and Operational Techniques Even Beginners Can Reproduce

RTK positioning (Real-Time Kinematic) is an essential technology that allows the acquisition of centimeter-level high-precision position information in real time for surveying and construction sites. If you can obtain a high-precision Fix solution (fixed solution) with RTK, the reliability of survey results improves dramatically and operational efficiency soars. However, in actual fieldwork, satellite signal occlusion by buildings or trees, signal reflections (multipath), communication interruptions, and other factors can cause the solution to remain as a Float solution or make the Fix state unstable. To increase the Fix rate, it is crucial to grasp several basic points and perform appropriate settings and operations.

This article systematically introduces tips to improve Fix rate that even RTK beginners can practice. From basic measures such as checking satellite reception status and reviewing the environment, to checking correction information and base station settings, and handling equipment, we cover a wide range of reproducible techniques. At the end, we also introduce simple surveying using LRTK, which makes RTK positioning easier to utilize.

Table of Contents

• Checking and improving satellite reception status

• Measures for positioning environment (obstructions and multipath)

• Checking correction data reception and communication status

• Base station settings and baseline length optimization

• GNSS receiver settings and hardware checks

• Simple surveying using LRTK

• FAQ

Checking and improving satellite reception status

Checking satellite lock status is the starting point for improving Fix rate. For stable Fix solutions in RTK, it is said to be desirable to capture 5–6 or more GNSS satellites at the same time. Theoretically, three-dimensional positioning is possible with four satellites, but if satellites are barely four, the accuracy is poor and obtaining a fixed solution becomes difficult. Check the number of currently received satellites and DOP values (Dilution of Precision) on the status screen of the positioning device or dedicated app to see whether the required number of satellites is satisfied. If the number of satellites is insufficient, using a multi-GNSS-capable receiver to take advantage of satellites other than GPS (GLONASS, Galileo, QZSS, etc.) can increase the total number of satellites that can be captured. Increasing the number of satellites lowers the DOP value and leads to an improved Fix rate.

Satellite geometry is also an important point. If satellites are biased toward one part of the sky, the geometric configuration is weak, the DOP value rises, and accuracy worsens. The more evenly satellites are distributed across the sky, the better the positioning accuracy and the more stable the Fix solution tends to be. When satellite geometry is biased, the initialization to a fixed solution can take longer or remain as a Float solution. Therefore, it is effective to use tools such as a GNSS planner to check satellite geometry and visible satellite counts in advance and choose times with as low DOP values as possible for surveying. For example, aiming for times when several satellites are high overhead makes them less likely to be blocked by buildings and improves accuracy. Also check the receiver’s elevation mask setting (the angle used to exclude low-elevation satellites). If the elevation mask is set too high, the number of available satellites itself decreases, so be careful. Generally, setting it around 15° allows moderate use of low-elevation satellites while balancing satellite count and accuracy. In noisy urban environments, raising it to around 20° to exclude low-elevation satellites that are noise sources is an option, but note that this reduces the number of usable satellites.

Measures for positioning environment (obstructions and multipath)

The surrounding environment at the site greatly affects RTK Fix rate. In places with a narrow sky view, satellite signals cannot be received sufficiently and obtaining a fixed solution becomes difficult. In environments surrounded by buildings, such as high-rise downtown areas (so-called "urban canyons"), only part of the sky is visible and the necessary number of satellites cannot be secured. The basic rule is to perform positioning in a location where the surroundings are open as much as possible. Moving just a few meters can let satellites appear from behind building shadows, increasing the number captured and leading to a Fix. In particular, securing a view toward the north often balances satellite geometry, so choose points with few obstacles.

Also be aware of multipath (signal reflections) in urban or forested areas. If satellite signals are reflected by building façades, metal fences, vehicles, etc., and then reach the receiver, they arrive later than the direct wave and cause an apparent increase in distance. This multipath error is a major enemy of RTK, significantly degrading positioning accuracy and preventing Fix solutions. As countermeasures, it is ideal to move away from tall buildings and large structures likely to reflect signals. If you must survey near a building, try the following measures:

• Raise the antenna height: Install the positioning antenna as high as possible to reduce the influence of surrounding reflected waves (use tall poles or tripods). In strong winds, secure the antenna so it does not sway.

• Attach a ground plane to the antenna: If possible, attach a conductive mounting plate such as a metal sheet directly beneath the antenna. This blocks reflections from below and the ground and reduces multipath effects.

• Choose the positioning point carefully: Simply moving the survey point a few meters away from a wall can mitigate reflections. Also effective is initializing to a Fix once at an open location and then moving to the target position. Some receivers can maintain Fix for a short period even if the environment temporarily worsens after obtaining a Fix.

Also check whether there are strong radio interference sources nearby. Directly under high-voltage power lines or very close to communication antennas, strong electromagnetic noise may disturb GNSS reception. Construction radios and Wi‑Fi routers can also have an influence. Review the radio environment around the survey site and, if necessary, relocate or turn off interference sources. Thoroughly implementing these environmental measures will lead to more stable acquisition of Fix solutions.

Checking correction data reception and communication status

In RTK positioning, high precision is achieved only when correction data from a base station is received. Whether correction data is being received correctly is therefore directly linked to the Fix rate. If using a network RTK (Ntrip) system, first check the Ntrip connection status on the receiver or app. If the status display shows “Correction: Receiving” or the communication icon is normal (green, etc.), you are good. If it shows “Not connected” or an error, review the Ntrip settings (server address, port number, mountpoint name, user ID, password) for input mistakes. Even a single-character error can prevent server connection, so check carefully. Also, if connected via a mobile network, confirm that the smartphone or router is connected to the Internet and has sufficient signal strength. In tunnels or mountainous areas, cellular signals may be unavailable and correction data can be interrupted, so be cautious.

The type and quality of correction data also affect the Fix rate. Check that you are selecting correction information appropriate for your receiver. If you have a single-frequency (L1-only) receiver, you need to use correction data provided for that type of device. If your receiver is multi-frequency capable, using higher-precision correction formats (e.g., multi-frequency data) makes Fixing easier. For example, some correction service providers offer different mountpoints for single-frequency and multi-frequency users. If you do not select data suitable for your receiver, integer ambiguity resolution may not work well and you may fail to obtain a Fix.

If you use your own base station for local RTK, check the radio communication status. Verify that the base station transmitter (such as UHF radio) is operating correctly and that its signal reaches the rover. In urban areas, interference from other radio stations or attenuation by obstacles can reduce communication distance below expectations. If necessary, improve the communication environment by installing the base-station antenna at a higher location, setting up a repeater, or using a higher-power radio. If radio channels or frequency bands are congested, consider switching to an available channel. If correction data is frequently interrupted, a Fix solution cannot be maintained, so stabilizing communications is important.

Base station settings and baseline length optimization

Incorrect base station settings or positional issues can also cause RTK not to Fix. If you operate your own base station, first review the base station coordinate settings. It is ideal to set the base station with as accurate a known coordinate as possible. Even if you operate using short-term approximate measured values or provisional coordinates, entering coordinates far from the actual location can create a large initial position error in the solution and make Fix unstable. If the configured coordinate error is tens of meters or more, integer initialization on the rover may take a long time or fail. If possible, precisely measure the base station position in advance (long static observation, tying to public control points, etc.) and use those coordinates.

Also make sure the coordinate systems (geodetic datums) match. In Japan, world geodetic systems such as JGD2011 are used; if the base station is configured in a local custom coordinate system or the rover and base station use different reference systems, offsets will occur after applying corrections and Fixing will fail. Confirm that the base and rover use the same geodetic/coordinate system.

Baseline length (distance between base and rover) greatly affects Fix rate. Generally, as baseline length increases, RTK accuracy and time to Fix tend to worsen. Within about 10 km, it is relatively easy to obtain a Fix solution, but as distance increases to 20 km, 30 km, ionospheric and tropospheric error differences increase, making integer fixing slower or less stable. At distances beyond 50 km, depending on conditions, Fix may rarely be achieved. As a countermeasure, install the base station as close to the work site as possible. If you must use remote base station data, consider using national or commercial network RTK services (VRS, etc.). VRS (Virtual Reference Station) services generate virtual base station information near the user, effectively shortening the baseline to a few kilometers. If public Continuously Operating Reference Stations (CORS) or commercial correction services are available, selecting the nearest base station data will significantly mitigate distance issues.

Additionally, check the installation environment of the base station itself. If the base antenna is placed in a location with poor sky view, such as a building rooftop surrounded by obstructions, those error factors may be included in correction data and adversely affect the rover solution. Place the base station in an open, secure location and accurately measure and input the antenna height. Also verify that the base station is functioning properly (power and communications are not cut off). If base station transmission stops, the rover obviously cannot Fix. By optimizing base station settings and operation as described, you can greatly improve the RTK Fix rate.

GNSS receiver settings and hardware checks

Finally, check the GNSS receiver settings and hardware status you are using. Surprisingly, connection faults or configuration mistakes in equipment can cause failure to Fix. First, on the hardware side, inspect for loose or broken cables when using an external antenna. If the antenna connector is not firmly connected, the satellite signal can become extremely weak and required accuracy cannot be obtained. If a device that used to Fix well suddenly fails to Fix, suspect an antenna cable problem or antenna malfunction. Trying a replacement antenna or reconnecting the cable may improve the situation.

For RTK receivers that pair with smartphones or tablets, watch for app-side bugs. If an app or software freezes and stops updating correction information, Fix cannot be maintained. In that case, restart the app or reboot the smartphone and reconnect to the receiver.

Next, review internal settings of the receiver and positioning software. Check whether positioning mode or satellite use settings have unintentionally changed. For example, moving a rover while it is in Static mode leads to unstable solutions, whereas observing a stationary point for a long time in a dynamic (Kinematic) mode can introduce unnecessary errors. Select mode settings appropriately for the operation. Also ensure consistency in satellite system settings between the base and rover. If one side has GLONASS disabled while the other has it enabled, corresponding correction data may not be available and Fix may fail. In principle, configure the base and rover to use the same satellite systems (GPS, GLONASS, Galileo, QZSS, etc.).

Whether a receiver is single-frequency or multi-frequency also has a large impact on Fix rate. Single-frequency (L1-only) GNSS devices cannot fully correct ionospheric errors, so Fixing tends to take longer or be unstable. If possible, use a multi-frequency receiver that supports L1/L2 or L5 to significantly improve time-to-Fix and Fix stability. Modern high-precision GNSS terminals are increasingly multi-frequency capable, so consider this when introducing new equipment.

If you still cannot obtain a Fix in the field, return to the basics and check the points above comprehensively. Inspecting satellite reception, surrounding environment, correction data, base station, and device settings in that order will resolve many issues. Also, when Fix cannot be obtained on the spot, it is important to wait and retry rather than forcing it. Waiting for an improved satellite geometry or a more stable ionosphere and retrying later can lead to a Fix. Continuing to measure with a Float solution for a long time does not improve accuracy, so identify the cause and take countermeasures before retrying. As alternatives, consider switching to PPK (post-processed kinematic) or, for a simple approach, taking multiple measurements of a Float solution and averaging to secure accuracy.

Finally, do not forget to keep receiver and app firmware/software up to date. Older versions may contain bugs affecting RTK solutions. If the manufacturer or provider releases the latest firmware, update and always operate with the latest version to help ensure stable Fix acquisition.

Simple surveying using LRTK

By following the points introduced so far, you can increase RTK Fix rate and achieve stable, high-precision positioning. However, some people may find it burdensome to manage all these settings and operations themselves. For beginners with little GNSS or RTK expertise, handling devices can be a hurdle. A solution that responds to the need to “use RTK positioning more easily” is simple surveying using LRTK.

The LRTK series is a product lineup of compact high-precision GNSS receivers provided by Lefixea Co., designed so anyone at the site can easily use centimeter-level positioning. The compact receiver body fits in your pocket and, when paired with a smartphone or tablet via a dedicated app, realizes high-precision RTK positioning. It supports multi-GNSS and multi-frequency operation, covering the satellite count and frequency issues described above. Usage is simple: attach it to your smartphone and start positioning in the app. Cumbersome base station setup and Ntrip connections can be done intuitively within the app, so beginners can operate it without trouble.

With LRTK, tasks that previously required specialized surveying equipment can be handled easily by one person. It also includes functions to instantly record and share high-precision positioning data to the cloud, contributing to productivity improvements in civil engineering and construction sites. It incorporates the latest technology compatible with the Ministry of Land, Infrastructure, Transport and Tourism’s “i-Construction” initiative and will significantly transform on-site surveying workflows. If you have concerns about introducing or operating RTK positioning, please consider using the LRTK series. For details, see the [LRTK official site](https://www.lrtk.lefixea.com/). Feel free to contact us with product questions, demo requests, or inquiries about deployment. LRTK can help take your company’s surveying operations to the next level.

FAQ

Q1: How many satellites are minimally required to obtain a stable Fix solution in RTK? A: Theoretically, three-dimensional positioning is possible with four satellites, but to reliably obtain a fixed solution in RTK it is desirable to simultaneously capture 5–6 or more satellites. The more satellites the better; using a device that supports multi-GNSS (GLONASS, Galileo, QZSS, etc.) in addition to GPS increases the number of available satellites and, as a result, improves the Fix rate.

Q2: If RTK does not Fix easily, how long should I wait? A: Under good environmental and equipment conditions, it is common to reach Fix within tens of seconds to a few minutes after powering on the receiver or starting positioning. If it still has not Fixed after 5 minutes, some problem is likely. In that case, recheck the points covered in this article (satellite count, surrounding environment, correction data reception, base station settings, equipment condition, etc.). Unless you identify and remedy the cause, continuing to measure as a Float solution for a long time will not improve accuracy. Troubleshoot the issue and retry positioning.

Q3: Do weather or time of day affect the likelihood of Fix? A: Rain or cloudy weather does not dramatically attenuate GNSS signals, but time-of-day effects are possible. Disturbances in the ionosphere tend to be larger in the afternoon (for example, around 14:00–17:00), which can degrade accuracy. In urban areas, satellites may be biased to low elevations at certain times and more easily blocked by buildings. If you find Fix difficult due to environmental factors, try changing the time and retry. In practice, some users have found Fixing easy in early morning or nighttime.

Q4: Is it acceptable to continue measuring with a Float solution? A: Float solutions are less accurate than Fix solutions and generally have errors on the order of tens of centimeters to about 1 m (tens of centimeters to about 1 m (tens of inches to about 3.3 ft)). For precise surveying or construction control, a Float solution is inadequate. If you cannot obtain a Fix quickly, do not hurriedly record Float solution values; it is safer to wait until Fix is achieved or retry later. If Fix cannot be obtained on site, consider switching to Static positioning (long observation with post-processing). Alternatively, as a simple method, measure the same point multiple times and average to reduce error.

Q5: What should I do at a site far from the base station? A: When the distance from the base station is large, obtaining a Fix becomes difficult, so if possible, use public network RTK services (VRS, etc.). With VRS, a virtual reference point is set near the user, eliminating distance issues. If you must work with a long distance to your own base station, strengthen communications by installing repeaters, using higher-power radios, or expanding radio coverage. If those are impractical, consider temporarily relocating the base station closer to the survey point or using post-processing (PPK or long static observations).