What causes slow RTK initialization? 6 things to check

When using RTK in the field, initialization can take longer than expected, delaying the start of work. Even if positioning itself is possible, long waits for the fixed solution to stabilize greatly reduce observation efficiency. In particular, in practical tasks such as construction, surveying, inspection, and as-built verification, slow initialization directly leads to disrupted scheduling and increased re-measurements, so it should not be dismissed as a mere quirk of the equipment.

When RTK initialization is slow, multiple factors often affect it simultaneously—not just the reception environment but also how correction data is received, satellite geometry, the setup method, how the receiver is moved, and the procedures for starting observations. In other words, instead of attributing the cause to a single factor, it's important to systematically isolate the conditions related to initialization one by one.

In this article, we organize and explain six representative causes of slow RTK initialization that field personnel can easily check on site. We also introduce approaches for shortening initialization time and how to establish reproducible operational procedures.

Table of Contents

• Basics you should understand first when RTK initialization is slow

• 1 thing I want to confirm: whether there is a problem with the satellite reception environment

• 2. Whether the correction information is being received stably

• Item 3 to confirm: whether the setup and stationary conditions at the start of observation are in order

• Check item 4: whether usage immediately after moving or immediately after resuming has become unstable

• 5 things to check: whether the settings and operational rules are feasible

• Check whether the 6 error factors originating from the surrounding environment that you want to verify are not strongly present.

• Practical concepts to grasp to speed up RTK initialization

• Summary

Basics you should understand first when RTK initialization is slow

RTK initialization refers to the process by which the conditions required to establish high-precision relative positioning are met and a stable fixed solution is achieved. Generally, simply receiving satellite signals and outputting a position can begin relatively quickly, but achieving the accuracy required for RTK demands stricter conditions. Standalone positioning or a coarse position display does not necessarily mean the system is in a sufficient state for RTK.

What becomes problematic in practice is not so much that initialization time is slightly long each time, but that it varies greatly depending on site conditions. In one location it may obtain a fixed solution quickly, while in another it may not stabilize even after a long wait. This difference arises not only from variations in the equipment's performance itself, but also from factors such as sky visibility, surrounding structures, communication conditions, the quality of correction information, antenna placement, and how the operator uses the equipment.

Also, when RTK initialization is slow, it not only takes time but also tends to affect subsequent positioning stability. If you start work without waiting for a fixed solution, it can result in coordinate dispersion and the need for re-surveys. Conversely, switching to an operational workflow that begins observations after preparing proper initialization conditions will often shorten the overall work time.

Therefore, to improve slow initialization, it is important not to rely on symptomatic quick fixes that only speed up the immediate attempt, but to understand why it is difficult to obtain a fixed solution in that environment and to translate that understanding into reproducible procedures. From here, we will go through the six items you should check, in order.

Check 1: Is there an issue with the satellite reception environment?

The most fundamental—and most easily overlooked—cause of slow RTK initialization is the satellite reception environment. RTK requires continuously receiving multiple satellite signals stably, but in locations where the sky is not sufficiently open the number of received signals may appear adequate while low-quality signals are actually mixed in. As a result, the solution becomes unstable and initialization takes longer.

For example, near buildings, under trees, around elevated structures, at the edges of slopes, or beside material storage areas, the portions of sky where satellites are visible can be partially blocked. Even if only part of the sky overhead is open, if visibility is uneven by direction it can be difficult to achieve the required satellite geometry. Rather than simply looking at the number of satellites, it is important to be aware of which directions of the sky are open and to what extent.

Another thing to watch out for is reflected waves. When metal surfaces, glass surfaces, bodies of water, exterior walls, large vehicles, heavy machinery, temporary fencing, and the like are nearby, not only the directly arriving signals but also reflected signals are likely to be received. This can disturb observations and prolong initialization. On site, people tend to assume it’s fine because the sky is visible, but in environments with strong reflections the conditions can be worse than they appear.

When checking the reception environment, first look not only at the observation point itself but also at the surroundings for several meters to a dozen or so meters. If obstacles are located right next to the antenna, the impact is particularly significant. It's not uncommon for initialization time to change dramatically with only a slight shift in position. When initialization seems slow on site, before suspecting the equipment settings, the basic practice is to first check the openness of the sky and the presence of reflective sources.

Also, conditions at the same location can differ between morning and afternoon. Because satellite geometry is constantly changing, initialization may proceed without problems at one time of day but become difficult at another. If initialization times vary significantly from day to day or between time periods, it is often easier to consider the combination of satellite geometry and the reception environment as the likely cause rather than operational issues.

Check Item 2: Is correction information being received consistently?

In RTK initialization, it is important not only that the rover is receiving satellite signals, but also that the reference correction information is being delivered continuously and stably. If reception of the correction information is unstable, it may appear that communication is possible, yet reaching a fixed solution can be delayed or, even if reached, quickly lost. On site, attention tends to focus only on the reception environment, but the quality of the correction information is just as important.

Especially when receiving correction information over a communication line, in areas with weak signal, during times when the network tends to be congested, or in locations with strong surrounding obstructions, data arrival can become intermittent. Even if the connection is not completely cut off, increased delays and dropouts can make initialization unstable. On site, people may be reassured merely because a communication indicator is lit, but what is truly required is continuity.

Also, the distance to the correction source and the method of delivery of the correction information also affect initialization time. In general, if the correction conditions do not match your observation location, initialization may take longer and the stability after obtaining a fixed solution may decrease. In practical work you do not need to judge all the fine theoretical details on site, but you should understand that, even at the same location, changing how you receive corrections can change the initialization time.

Also, be cautious when the communication has only just been established immediately before starting observations. The moment a communication link is made does not necessarily mean the RTK is immediately in a fully usable state. It is necessary for the correction information to begin flowing steadily and for the receiver to continue correctly ingesting it. If you rush to start observations right after connecting, you may end up waiting longer for initialization.

When checking this item, don't just verify whether communication is present; also check whether the status changes when you move to different locations on site, whether there is a time lag before behavior stabilizes after reconnection, and whether there are differences between using it while walking and using it while stationary—doing so makes it easier to isolate instability in the correction information. The slower the initialization at a site, the more important it is to verify the delivery quality of the correction information as part of operations.

Item 3 to confirm: Are the installation and stationary conditions in place at the start of observation?

RTK initialization is also strongly influenced by how the equipment is positioned and the conditions of stillness when observations begin. Even if the reception environment and correction data are fine, instability in the device’s orientation or vibration at the start of observation can prolong initialization time. On site, the more rushed the work, the more likely this aspect is to be handled sloppily, paradoxically resulting in longer waiting times.

First and foremost, keep the antenna and receiver as steady as possible. When using them handheld, continued body movement, arm sway, regripping, or changes in orientation make it difficult for the observation conditions required for initialization to be met. Especially immediately after starting observations, you may be tempted to move the device because the readings are changing, but it is precisely during this period that staying calm and keeping it still is most effective.

Next, operations where the installation height and tilt vary each time also lead to instability in initialization. Strictly speaking, this may seem separate from whether initialization itself is possible, but in practice the less stable the installation site is, the more likely the operator’s way of holding or placing the device is also unstable, and as a result it affects the time required to reach a fixed solution. On soft ground or slopes, you should also be aware of whether slight sinking or wobbling occurs after installation.

Also, trying to initialize equipment the moment it stops after having been moving until just before the start of observation may not work well. Immediately after walking, immediately after vehicle movement, or immediately after carrying the device, the reception state may be less settled than it appears. Simply waiting a short time and ensuring the device is stationary can sometimes shorten the initialization time.

At job sites, motivated by a desire to get things working quickly, people sometimes proceed with powering on, establishing communications, receiving corrections, and starting observations almost simultaneously. However, with RTK, compressing the procedures too much can actually slow down initialization. Even simply enforcing the sequence of setting up and then letting the unit remain stationary, waiting for the correction reception to stabilize, and confirming the solution status before beginning observations will tend to improve the reproducibility of initialization.

Check 4: Is usage unstable immediately after moving or immediately after resuming?

RTK tends to be thought of as remaining stable once it reaches a fixed solution, but in reality its state can change easily when you move or encounter obstructions. Furthermore, if your procedure for resuming use is careless, it can make initialization feel slow each time. This effect is especially likely to accumulate in field work that involves visiting multiple points in a short time.

For example, in operations where you obtain a fixed solution outdoors, then move close to a structure and later return to an open area, the conditions for satellite reception and correction reception can become disturbed along the way. To return to high-precision positioning from that state, the receiver needs time to re-establish the proper conditions. However, in the field people often assume that because it was working just a short while ago it should recover immediately, and so they do not wait when they should.

Also, in operations involving frequent, short cycles of observation and movement, the operators' movement flow itself can affect initialization time. If actions such as passing through heavily obstructed passages, moving between materials, or briefly stopping beside vehicles are consistently repeated each time, it gives the impression that initialization is slow across the entire site. It is not uncommon for the cause to lie not in the equipment but in the operational route.

If initialization is slow immediately after resuming, it is important to pay attention to when the status degraded. Checking whether it was stable before moving, where along the route it becomes difficult to recover, whether communication becomes weak upon resuming, and whether you are trying to observe immediately after moving will make it easier to identify the origin of the problem.

Moreover, in operations that repeatedly pause and resume, it is safer not to assume that the equipment’s state has been completely carried over. In practice, even if you think you only stopped briefly or moved slightly, satellite reception conditions and correction reception conditions may not be continuous. Therefore, upon resumption you should, every time, check the equipment’s state as carefully as you would during the initial initialization. Simply having this awareness will make it easier to reduce unnecessary standby time and measurement errors.

5 Things to Confirm: Are the settings and operational rules feasible?

When RTK initialization is slow, it's easy to focus only on field conditions, but in fact there are often cases where the settings or operational rules are unreasonable. For example, operational differences—such as proceeding to the next task without sufficiently confirming the solution state, having different pre-observation checklists for each operator, ambiguous standards for communication checks, and differing perceptions among people of how long to wait for initialization—tend to cause variability in initialization.

In practice, the more consistent the way equipment is used at a site, the more stable the initialization tends to be. Conversely, even when the same equipment is used, if initialization times differ between people at a site, operational differences may have a greater impact than the equipment’s performance. This is not just an issue of the operator’s level of experience; it can also be caused by decision criteria that have not been standardized.

Also, operating in a way that begins work as soon as the numbers merely look plausible without allowing sufficient time for initialization is dangerous. The apparent position display and a fixed solution that can be trusted as RTK are not the same. Even if the changes shown look small, the system may still be unstable internally. The stronger the urge to finish quickly, the more likely this stage will be skipped, but as a result there will be increased error checks and rework in later processes.

Furthermore, it is also a problem that information about places that are easy or difficult to initialize at each site is not being shared. If insights about where it is faster to start up, at which positions waiting leads to greater stability, or which routes tend to make the system unstable are not accumulated, the same failures will be repeated every time. Rather than leaving the slowness of initialization to individual judgment, organizing it into site rules makes it easier to improve.

Even on the settings side, if you use the system without fully understanding the update conditions and display conditions, you can make wrong judgments about initialization. It is not necessary for everyone to understand the detailed theory, but at a minimum the rules should be standardized about what counts as ready to start observation, which states should be waited out, and what signs indicate that reinitialization is necessary. To reduce slow initialization, it is effective to reduce operational variability before increasing the equipment’s capability.

6 checks to confirm that environmentally induced error factors are not strongly present

At sites where RTK initialization is slow, error sources originating from the surrounding environment can be pronounced, not just problems with satellite visibility or communication. These are not always immediately obvious to the eye: the site’s terrain and the arrangement of structures, the materials nearby, and the movements of surrounding machinery during operations can combine and interact, making it difficult to pinpoint the cause.

A typical example is the effect of multipath. Near reflective surfaces, direct and reflected signals easily mix, making measurements unstable. On sites where metal temporary structures, handrails, fences, exterior cladding, large vehicles, heavy machinery, material racks, and the like are nearby, initialization can be slow even when the sky appears open. From an operator’s perspective it’s easy to assume that being outdoors means there’s no problem, but in reality the reflective environment can be dominant.

Surface conditions should not be ignored. Near puddles, wet pavement, or large concrete surfaces, signals can be more prone to reflections depending on the environment. Also, near slope faces, cut-and-fill sections, or embankments, sky visibility becomes biased and reception conditions vary by direction. As a result, the ease of initialization can differ from one location to another.

Additionally, there are situations where you should suspect interference from nearby machinery or communications equipment. It does not always become a major problem, but if initialization is slow only in specific locations or at certain times, it is worth checking for a connection with the surrounding operating conditions. For example, if the system becomes unstable only when heavy machinery is nearby, or responses are delayed only near temporary installations, the likelihood of environmental factors is higher.

Be aware that these environment-derived issues can easily be mistaken for equipment failure. If a device works normally at other sites but is slow only at a specific site or location, you should first suspect environmental factors. Conversely, if it is slow everywhere you go, you should look more closely at settings, equipment condition, or problems receiving correction information. Although slow initialization may appear the same from the symptoms alone, the way you address it differs completely depending on whether it is site-dependent or persistent.

Practical concepts to grasp to speed up RTK initialization

The six items we've reviewed so far may appear to be independent causes, but in practice it is common for multiple factors to overlap simultaneously. Therefore, if you want to speed up RTK initialization, rather than chasing a single cause it is important to adopt the approach of arranging conditions favorable to initialization from the outset.

First, keep in mind that initialization is not a preliminary step before observation, but part of observation quality. Waiting for initialization is not wasted time; it is preparation time to reduce rework in downstream processes. The more you rush this, the more overall efficiency tends to decline. If you want to shorten on-site working time, focus not on clever ways to avoid waiting but on measures that create conditions where waiting is unnecessary.

Specifically, when you arrive on site, it is effective to first choose a location where initialization is easy, ensure stable transmission and reception there, and then proceed with each task. Rather than starting up on the spot for every observation point each time, deciding on a starting point with better conditions tends to improve overall reproducibility. Also, at sites where movement tends to disturb the setup, reviewing the movement flow itself can be effective.

Next, reducing variations in judgment among operators is also important. If you concisely standardize which display states to check, which states should result in continued waiting, and what to review when resuming, variability in initialization time will tend to decrease. Especially at sites operated by multiple people, relying solely on individual experience makes it hard to determine whether problems are reproducible.

Additionally, recording locations where initialization was slow will lead to improvements next time. Even briefly noting where it was slow, how many minutes it took, and what was around at the time makes it easier to separate environmental factors from operational ones. Initialization issues cannot always be resolved on site, but keeping records allows you to turn them into site-wide accuracy management.

RTK is highly accurate, but it is also a technology that is easily affected by conditions. Therefore, when initialization is slow, rather than hastily increasing operations, calmly reviewing the reception environment, correction information, stationary conditions, procedures for resuming after movement, operational rules, and the surrounding environment in that order is the most practical way to improve the situation.

Summary

There is not a single cause for slow RTK initialization. Multiple conditions affect initialization time, such as poor satellite reception, unstable correction data, not remaining sufficiently still at the start of observation, crude restart procedures immediately after movement, non‑standardized settings and operating rules, and strong reflections or error sources from the surrounding environment. Therefore, to improve slow initialization you should not suspect the equipment alone but review site conditions and operational practices together.

In practice, what matters more than the time to reach a fixed solution itself is whether each startup is stable. If it’s fast today but slow tomorrow, varies by the person in charge, or shows extreme variation by location, it becomes difficult to manage quality across the entire site. First, check the six items introduced here in order, and start by visualizing under which conditions it becomes slow — doing so will make it easier to grasp the direction for improvement.

If you want to operate high-precision positioning stably in daily work, it is important to consider equipment and procedures not only in terms of whether coordinates can be obtained, but also including ease of initialization, ease of resuming, and ease of handling on site. If you proceed with introduction or review from that perspective, iPhone-mounted GNSS high-precision positioning devices like LRTK are a strong option when considering the balance between on-site handling and high-precision positioning. Especially if you are having trouble with RTK initialization, it is important to review the entire operation not only from the viewpoint of positioning accuracy but also from the perspectives of startup stability and ease of use in practical work.