RTK positioning (Real-Time Kinematic) is an important technology that enables acquisition of high-precision position information with an accuracy of a few centimeters (cm level accuracy / half-inch accuracy) in real time for surveying and construction sites. If you can obtain a high-precision Fix solution (fixed solution) with RTK, the reliability of surveying results improves dramatically and work efficiency soars. However, in actual field conditions it is not uncommon for the solution to remain a Float solution (float solution) or for the Fix state to become unstable due to satellite signal blockage by buildings or trees, radio signal reflections (multipath), communication interruptions, and other causes. To raise the Fix rate, it is essential to perform appropriate settings and operations after grasping several basic points.

This article systematically introduces tips for improving Fix rate that RTK beginners can also practice. From basic measures such as checking satellite reception status and reviewing the environment to correction data and base station settings checks and equipment handling, we cover a wide range of reproducible techniques. At the end, we also introduce simple surveying with LRTK to make RTK positioning easier to use.

Table of Contents

• Check and improve satellite reception status

• Measures against measurement environment (obstructions and multipath)

• Check correction data reception and communication status

• Base station settings and baseline length optimization

• GNSS receiver settings and hardware checks

• Simple surveying with LRTK

• FAQ

Check and improve satellite reception status

Checking satellite acquisition status is the starting point for improving Fix rate. For stable Fix solutions in RTK, it is said to be desirable to simultaneously capture five to six or more GNSS satellites. Theoretically, three-dimensional positioning is possible with four satellites, but when there are barely four satellites the accuracy is poor and it becomes difficult to obtain a fixed solution. Check the number of currently received satellites and the DOP value (Dilution of Precision) on your receiver or dedicated app status screen to determine whether the required number of satellites is being met. If the number of satellites is insufficient, you can increase the total number of satellites captured by using a receiver that supports multi-GNSS and utilizing satellites other than GPS (GLONASS, Galileo, Michibiki (QZSS), etc.). Increasing the number of satellites lowers the DOP value and leads to improved Fix rate.

Satellite geometry is also an important point. If satellites are biased toward one direction of the sky, the geometric configuration becomes weak, DOP rises, and accuracy deteriorates. 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, initialization to a fixed solution may take time or remain as a Float solution. Therefore, it is effective to check satellite geometry and the number of visible satellites in advance using tools such as a GNSS planner, and choose times with as low DOP values as possible for surveying. For example, targeting times when multiple satellites are high overhead reduces the chance of being shadowed by buildings and improves accuracy. Also check the receiver’s elevation mask setting (the angle that excludes low-elevation satellites). If the elevation mask is set too high, the number of usable satellites decreases, so be careful. Generally, setting it to around 15° allows some low-elevation satellites to be used while balancing satellite availability and accuracy. In noisy environments such as urban areas, raising it to around 20° to exclude low-elevation satellites that act as noise sources is an option, but note that this reduces the number of usable satellites.

Measures against measurement environment (obstructions and multipath)

The surrounding environment at the site greatly affects RTK Fix rate. In places with limited sky visibility, satellite signals cannot be received sufficiently and it becomes difficult to obtain a fixed solution. In environments surrounded by buildings, such as downtown canyons, only part of the sky may be visible and you may not be able to secure the necessary number of satellites. The basic approach is to conduct positioning in a place where the surroundings are open as much as possible. Simply moving a few meters (a few meters) may allow satellites to appear from behind a building shadow, increasing the number of satellites and leading to a Fix. In particular, securing visibility to the north often helps balance satellite geometry, so choose points with fewer obstructions.

Also pay attention to multipath (signal reflection) near urban areas or forests. When satellite signals are reflected by building surfaces, metal fences, vehicles, etc., and then received by the receiver, they arrive with a delay compared to the direct wave, causing the measured distance to be overestimated. This multipath error is a major enemy of RTK, significantly degrading positioning accuracy and preventing Fix solutions. As a countermeasure, it is ideal to keep away from tall buildings and large structures that are likely to reflect radio waves. If you must survey near buildings, try the following measures:

• Raise the antenna height: Place the positioning antenna as high as possible to reduce the influence of reflected waves from the surroundings (use tall poles or tripods). Be sure to secure the antenna in strong winds so it does not sway.

• Attach a ground plane to the antenna: If you can attach a conductive base such as a metal plate directly under the antenna, do so. This blocks reflections from below and from the ground, reducing multipath effects.

• Choose measurement points carefully: Moving the point a few meters away from the wall can sometimes mitigate reflections. Also, obtaining a Fix once in an open location before moving to the target position is effective. Some receivers can maintain Fix for a short time even if the environment worsens slightly after a Fix has been achieved.

Also check whether there are strong radio interference sources nearby. Directly under high-voltage power lines or close to communication antennas, strong electromagnetic noise may disturb GNSS reception. Construction radios and Wi‑Fi routers can also have effects. Review the radio environment around the measurement site and, if necessary, move the location or turn off the power of interference sources. Thorough implementation of the environmental measures described above will help obtain more stable Fix solutions.

Check correction data reception and communication status

RTK achieves high precision only when it receives correction data from a base station. Therefore, whether correction data is being delivered correctly is directly related to Fix rate. If you are using network RTK (Ntrip method), first check the Ntrip connection status on the receiver or app. Status displays such as “Correction: Receiving” or a normal communication icon (green, etc.) indicate all is well. If it shows “Not connected” or an error, review the Ntrip settings (server address, port number, mountpoint name, user ID and password) to ensure there are no input mistakes. Even a single-character typo can prevent connection to the server, so check carefully. Also, if you are connecting via mobile data, confirm that the smartphone or router is connected to the Internet and that signal conditions are good. Correction data can be interrupted in tunnels or mountainous areas where mobile signals do not reach, so be cautious.

The type and quality of correction data also affect Fix rate. Confirm that you are selecting correction information appropriate for the receiver you are using. If you have a single-frequency (L1-only) receiver, you need to use the simple correction data provided for that model. If you have a multi-frequency receiver, using higher-precision correction formats (for example, data supporting multiple frequencies) makes it easier to obtain a Fix. Some correction services provide different mountpoints for single-frequency and multi-frequency data. If you do not choose data suitable for your receiver, ambiguity resolution (integer ambiguity fixing) may not work well and Fix will not be attained.

For local RTK using your own base station, check the radio communication status. Confirm that the base station’s transmitter (such as UHF radio) is operating correctly and that signal reaches the rover. In urban areas, communication range may be reduced below expectations due to interference from other radio stations or attenuation by obstacles. Improve the communication environment as needed by installing the base station antenna at a higher location, setting up repeater stations, or using higher-power radios. If radio channels or frequency bands are congested, consider changing to a free channel. If correction data is frequently interrupted, Fix solutions cannot be maintained, so stabilizing communication is critical.

Base station settings and baseline length optimization

Incorrect base station settings or positional issues at the base station can also cause RTK not to Fix. If you operate your own base station, first review the base station coordinate settings. Ideally, set the base station to as accurate a known coordinate as possible. Even when operating with a short-term quick survey value or provisional coordinates, entering values that are far from the actual position can cause large errors in the initial solution and destabilize Fix. Particularly if the error is on the order of tens of meters or more, integer initialization at the rover may take time or fail. If possible, measure the base station position precisely in advance (long static surveying or tying to public coordinates) and use that coordinate.

Also confirm that the coordinate systems (geodetic systems) match. In Japan, world geodetic systems such as JGD2011 are used, but if the base station is set in a local custom coordinate system or the rover and base station use different reference coordinate systems, an offset error will occur in the solution after applying corrections and proper Fix will not be achieved. Make sure both base and rover are using the same geodetic/coordinate system.

Baseline length (distance between base and rover) has a large impact on Fix rate. In general, as baseline length increases, RTK accuracy and time to Fix tend to worsen. Within 10 km it is relatively easy to obtain a Fix solution, but as distance increases to 20 km or 30 km, differences in ionospheric and tropospheric errors grow and integer fixing often takes longer or becomes unstable. At distances over 50 km, depending on conditions, you may hardly get a Fix. As a countermeasure, place the base station as close to the work site as possible. If you must use distant 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 service subscriptions are available, choosing the nearest base station data can greatly mitigate the distance problem.

Additionally, check the installation environment of the base station itself. If the base station antenna is installed on a roof in a location with poor sky view, those error factors will mix into the correction information and adversely affect the rover solution. Install the base station in as open and secure a location as possible and accurately measure and enter the antenna height. Also verify that the base station is operating normally (power and communication are not cut). If base station transmission stops, the rover obviously cannot obtain a Fix. Optimizing base station settings and operation as described above can significantly improve RTK Fix rate.

GNSS receiver settings and hardware checks

Finally, check the GNSS receiver settings and hardware condition you are using. Surprisingly, connection failures or configuration errors can cause the receiver not 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, satellite signals will be extremely weak and the required accuracy cannot be achieved. If a device that previously Fix'ed without problems suddenly fails to Fix, antenna cable faults or antenna failure may be suspected. Trying a replacement antenna or reconnecting the cable may resolve the issue.

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

Next, review internal settings in the receiver and positioning software. Check whether positioning mode or satellite usage settings have been changed without your knowledge. For example, moving a rover while it is set to Static mode may cause unstable solutions, whereas observing a static point for a long time in Kinematic mode can introduce unnecessary errors. Choose mode settings according to operation. Also ensure that the GNSS constellations enabled at the base and rover are consistent. If one side has GLONASS disabled while the other has it enabled, corresponding correction information may be missing and Fix may fail. As a basic rule, set both base and rover to use the same satellite systems (GPS, GLONASS, Galileo, Michibiki, etc.).

Whether the receiver is single-frequency or multi-frequency greatly affects Fix rate. Single-frequency (L1-only) GNSS devices cannot fully correct ionospheric errors, so time to Fix may be longer and stability lower. If possible, use a multi-frequency receiver that supports L1/L2 or L5 to dramatically improve Fix acquisition speed and stability. Recent high-precision GNSS terminals increasingly support multi-frequency, so consider such models when introducing new equipment.

If you still cannot get a Fix in the field, go back to basics and comprehensively inspect the points above. By checking satellite reception, environment, correction data, base station, and device settings in that order, many problems can be solved. Also, if Fix cannot be obtained on site, it is important to refrain from forcing it and to wait and retry. Sometimes simply waiting for an improvement in satellite geometry or for ionospheric conditions to stabilize allows a Fix. Continuing to measure in a Float state for a long time will not improve accuracy, so identify the cause and take countermeasures before reattempting. In some cases, consider alternatives such as switching to PPK (post-processed kinematic) or taking multiple measurements in Float and averaging them to ensure accuracy.

Finally, do not forget to keep your receiver and app firmware/software up to date. Old versions may contain bugs that affect RTK solutions. If the manufacturer or provider has released the latest firmware, update and operate in the most recent state to shorten the path to acquiring stable Fix solutions.

Simple surveying with LRTK

By applying the points introduced so far, you can increase RTK Fix rate and achieve stable high-precision positioning. However, managing all these settings and operations yourself can feel burdensome. For beginners with limited GNSS or RTK knowledge, handling the equipment itself can be a hurdle. A solution to the need for “using RTK positioning more easily” is simple surveying with LRTK.

The LRTK series is a lineup of compact high-precision GNSS receivers offered by Lefixea, developed so that anyone on site can easily use centimeter-level positioning (cm level accuracy / half-inch accuracy). The compact receiver body that fits in your pocket is a key feature; by pairing with a smartphone or tablet through a dedicated app, it enables high-precision RTK positioning. It supports multi-GNSS and multi-frequency, covering the satellite count and frequency issues mentioned above. Usage is simple: attach to your phone and start positioning in the app. Complex base station settings and Ntrip connections can be performed intuitively within the app, so beginners can operate without confusion.

Using LRTK enables tasks that previously required specialized surveying equipment to be handled easily by one person. It also includes functions to immediately record and share high-precision positioning data to the cloud, contributing to productivity improvements in civil engineering and construction sites. With the latest technology that supports the Ministry of Land, Infrastructure, Transport and Tourism’s “i‑Construction,” it can greatly transform on-site surveying styles. If you are concerned about introducing or operating RTK positioning, please consider the LRTK series. For details, see the [LRTK official site](https://www.lrtk.lefixea.com/). Feel free to inquire about product questions, demo requests, or introduction consultations. LRTK will likely help take your surveying operations to the next level.

FAQ

Q1: How many satellites are minimally required to reliably obtain a Fix solution in RTK? A: Theoretically, three-dimensional positioning can be computed with four satellites, but to reliably obtain a fixed solution in RTK, it is desirable to simultaneously capture five to six or more satellites. The more satellites, the better; using a device that supports GPS plus GLONASS, Galileo, Michibiki and other multi-GNSS increases the number of available satellites and thus improves Fix rate.

Q2: If RTK does not Fix easily, how long should I wait? A: If the environment and equipment are in order, it is common for the receiver to enter Fix within tens of seconds to a few minutes after powering on or starting positioning. If it has been more than 5 minutes without a Fix, there is likely some cause. In that case, recheck the points discussed in this article (satellite count, environment, correction data reception, base station settings, equipment status, etc.). Unless the cause is identified and countermeasures taken, continuing to measure in a Float state for long periods will not improve accuracy. Troubleshoot and resolve the problem before attempting positioning again.

Q3: Do weather or time of day affect how easily Fix is obtained? A: Rain or cloud cover does not drastically attenuate GNSS radio waves, but time-of-day effects can be considered. Disturbances in the ionosphere tend to be larger in the afternoon (for example, around 14:00–17:00), and accuracy can degrade. In urban areas, satellite angles may bias low in certain time windows and become shadowed by buildings. If you suspect environment-related difficulty in obtaining a Fix, trying at a different time can be effective. There are cases where Fix was achieved easily in early morning or at night.

Q4: Is it okay to continue surveying in a Float solution state? A: Float solutions are less accurate than Fix solutions and generally have errors on the order of several tens of centimeters to approximately 1 m (3.3 ft). For precise surveying or construction management, Float is insufficient. If you cannot obtain a Fix quickly, rather than hastily recording Float values, it is safer to wait for a Fix or try again later. If you cannot get a Fix on site, consider switching to Static positioning (long-duration observation with post-processing). Alternatively, as a simple measure, measuring the same point several times and taking an average can reduce error.

Q5: How should I handle sites far from the base station? A: When distance from the base station makes Fix acquisition difficult, it is effective to use public network RTK services (VRS, etc.) if possible. With VRS, a virtual reference point is set near the user and distance issues are resolved. If you must work with long distances to your own base station, strengthen communications by installing repeaters, using high-power radios, or similar measures. If that is still difficult, consider temporarily relocating a base station nearer to the survey point or using post-processing methods (PPK or long static observations).