Anyone Can Do GPS Surveying? High-Precision Positioning from Zero Expertise

In recent years, high-precision surveying techniques using GPS have advanced dramatically, and tasks that once had to be left to specialist surveyors—such as setting out positions and as-built measurements—can now be performed remarkably easily using the latest GPS positioning technologies. This article explains what GPS surveying is, how it differs from ordinary car navigation or smartphone GPS, the mechanism of high-precision GPS (RTK positioning), the challenges faced on site and solutions provided by modern technologies, and why the barriers to “anyone being able to do GPS surveying” are lower than ever. It also covers concrete surveying procedures and preparations, accuracy and reliability, applicability in indoor and mountainous areas, and examples of using survey data (cloud sharing, AR, point-cloud scanning, etc.). Finally, we introduce a new technology called “LRTK” that enables easy cm-level positioning on a smartphone and explore how such modern GPS surveying is changing the field.

What is GPS surveying? — How it differs from ordinary GPS

GPS surveying applies satellite positioning—using artificial satellites—to surveying. The GPS in car navigation systems and smartphones that we use daily is very convenient for searching addresses or showing your current location on a map, but its positional accuracy typically has errors on the order of several meters. For example, when viewing a map on a smartphone, your current location may be displayed offset by about 5-10 m (16.4-32.8 ft), which is caused by errors in the satellite signals. While a few meters of error is acceptable for everyday use, such deviations are not tolerable in surveying tasks like laying out building foundations or measuring land boundaries. Therefore, surveying requires much higher accuracy, and GPS surveying uses technologies that can determine positions with centimeter-level accuracy.

The biggest difference between ordinary GPS (more precisely GNSS) positioning and GPS surveying is the positioning accuracy. A typical single GPS receiver (determining position from satellites using only one receiver) will have errors of several meters as described above. In contrast, high-precision GPS technologies used in surveying can reduce errors to within a few centimeters. The key to this dramatic improvement in accuracy is error-correction techniques such as the RTK (Real-Time Kinematic) positioning described below. Satellite signals contain various error sources (satellite orbit and clock errors, signal delays in the atmosphere, ground reflections—multipath, etc.), and high-precision positioning applies specialized methods to correct these errors to achieve surveying-grade accuracy. In other words, even though both use “GPS,” the GPS positioning used for surveying is an entirely different, high-precision system. Note also that ordinary consumer GPS has particularly large errors in the vertical (altitude) direction, making accurate elevations difficult to obtain, but high-precision GPS surveying can limit vertical errors to a few centimeters as well.

What is high-precision GPS (RTK positioning)?

An indispensable technology for discussing high-precision GPS positioning is RTK (Real-Time Kinematic). RTK is a method that uses satellite positioning (GNSS) to perform real-time error corrections and achieve centimeter-level positioning. A major characteristic is that it is a relative positioning scheme that uses at least two receivers (a base station and a rover) simultaneously. Unlike single-receiver positioning, RTK exploits the relationship between the base and rover to cancel common errors and obtain high-precision results.

The basic flow of RTK positioning is as follows.

• Base station: A receiver installed at a point whose precise coordinates are known in advance receives signals from multiple GPS/GNSS satellites and computes in real time the difference (positioning error) between the position it measures and the known correct coordinates.

• Transmission of correction data: The base station sends the computed error information (correction data) to the rover via radio or the Internet.

• Rover: The receiver that performs positioning while moving applies the received correction data to its own positioning results and computes its accurate current position.

Because RTK performs positioning while receiving corrections from a base station, errors are removed in real time and high-precision coordinates can be obtained on site immediately. The ability to achieve centimeter-level accuracy in real time is a major advantage, allowing surveying work to proceed on the spot without waiting for post-processing. RTK is an evolution of conventional DGPS (Differential GPS) and notably measures precise distance differences by using the phase of the carrier wave of the GPS signal. By analyzing the phase differences of the radio waves, errors of several meters can be reduced to below a few centimeters.

To obtain high correction performance, the base and rover should not be too far apart. Generally, if the baseline distance between the two stations is within about 10 km (6.2 mi), common error sources are similar and the corrections are effective. If the distance is too large, differences in atmospheric conditions reduce correction accuracy, so RTK surveying is normally operated within a suitable distance. Recently, by using the Geospatial Information Authority of Japan’s GNSS reference-station data and commercial correction services (network RTK) via the Internet, it has become possible to obtain correction information remotely. This enables the use of RTK positioning over wide areas without having to install a private base station.

Challenges faced on surveying sites and their background

Current surveying sites face several issues that need to be solved:

• Shortage of skilled personnel: There are not enough people who can perform surveying, and the workforce is aging. Traditionally, surveys had to rely on licensed surveyors or highly experienced technicians, and not everyone on site could perform surveying freely.

• Burden of equipment and manpower: Conventional surveying requires large equipment such as total stations (TS) and levels, which are cumbersome to transport and set up, and at least two people were usually required—for example, an assistant holding a reflector prism. In confined sites or mountainous areas, simply setting up the equipment is a major effort.

• Time and cost: Measuring each point takes time, and surveying large areas requires multiple days and labor costs. Outsourcing to specialist vendors is expensive, and in small-scale projects adequate surveying is sometimes skipped.

• Difficulty of quality control: When people without expertise attempt surveying, measurement mistakes or overlooked errors can occur, leading to rework later. There are also many surveying-specific tasks that require knowledge, such as converting locally defined coordinate systems to public coordinate systems.

Given these circumstances, improving efficiency and reducing labor in surveying work has become an urgent issue in the construction and civil engineering industries. The Ministry of Land, Infrastructure, Transport and Tourism’s “i-Construction” initiative is promoting on-site introduction of ICT and automation technologies, with high-precision GNSS surveying as a key pillar. However, traditional high-precision GNSS equipment has been expensive and required expertise, which hindered widespread adoption. Against this background, there is growing expectation for realizing “GPS surveying that anyone can do.”

Anyone can do it? The lowering of barriers in modern GPS surveying

So, have modern GPS surveying technologies really made it possible for “anyone” to perform surveying? Looking at recently introduced devices and services, one is surprised at how low the barriers have become. Here are some points where usability has dramatically improved compared to the past.

• Single-person operation: Satellite positioning, unlike optical TS surveying, does not require an assistant to hold a prism at the target. You can place the positioning antenna and press a button to record positions, enabling one person to walk around and measure many points even on large sites. This is extremely valuable in labor-short sites.

• Small and lightweight equipment: Modern high-precision GNSS receivers have become pocket-sized. Antenna-integrated, smartphone-sized devices have appeared, weighing only a few hundred grams. This makes surveying in remote mountains or at heights much easier, without hauling heavy equipment.

• Intuitive smartphone apps: The user interface is increasingly provided as smartphone or tablet apps rather than dedicated controllers. Familiar smartphone screens allow intuitive operations like tapping the point you want to record while viewing the map or camera feed. The app guides you, so beginners can use the system without memorizing technical terms.

• Automation of advanced processing: Tasks that used to require expertise—such as receiving correction data from a base station or converting positioning results to a consistent geodetic coordinate system—are now automated. For example, measured coordinates can be converted in real time to Japan’s plane rectangular coordinate system and displayed on a map, or uploaded to the cloud with a single tap for sharing. This greatly reduces data management and conversion errors.

• Guidance for beginners: Modern devices display positioning quality clearly on screen and guide operational steps. When positioning is unstable, the device warns with colors or messages; when stable, it shows indicators like “Fix obtained,” so users can measure at the right time. Beginners can follow on-screen instructions to perform accurate surveying.

• Tilt correction and height offset: Some GNSS receivers have built-in tilt sensors that automatically correct for a slightly tilted survey pole. If you place the pole tip (foot) on the ground point to be measured, the app calculates the height offset, so you do not need to perform complex correction calculations. These features free users from cumbersome settings and calculations specific to surveying instruments, making them easy for anyone to use.

Thanks to these improvements, modern GPS surveying solutions have become so user-friendly that practical surveying on site is now possible “from zero expertise.” In the next section, we look at what you need to start GPS surveying and the steps involved.

Positioning mechanism, procedure, and required items

Here we describe the general procedure and preparations for conducting GPS surveying. High-precision positioning may seem complicated, but if you prepare the necessary items and follow the steps, it is surprisingly simple.

Required items:

• High-precision GNSS receiver (survey GPS device)… a dedicated receiver that supports centimeter-level positioning (cm level accuracy (half-inch accuracy)). The unit has an antenna and communication functions and is used in conjunction with a smartphone or similar device.

• Communication environment / correction service… a method to obtain RTK correction data. For example, if connecting to the Geospatial Information Authority of Japan’s reference-station network or a commercial VRS service over the Internet, you need mobile data on a smartphone and a service contract. Depending on the device and region, you can also receive centimeter-class augmentation signals (CLAS) from Japan’s Quasi-Zenith Satellite System “Michibiki” and obtain correction information without the Internet.

• Smartphone / tablet… a device to connect to the GNSS receiver and operate positioning, using a dedicated app.

• Survey pole or tripod… equipment to stably mount the receiver. It is used to place the antenna accurately over the ground point to be measured (many workflows measure by touching the pole tip to the survey point).

• Power / batteries… if operating the receiver and smartphone for extended periods, prepare spare batteries.

Basic positioning procedure:

• Site preparation: Upon arrival, choose a spot with a clear view of the sky (satellite reception is better where there are fewer tall buildings or trees nearby). Power on the receiver and connect it to your smartphone via Bluetooth or Wi‑Fi. If necessary, configure correction-service login settings (Ntrip information, etc.) in the app.

• Connect / configure base station: If using network RTK, connect to the correction data source (base-station network) from the smartphone app. If using your own base station, install that device at a known point and set it to “base station mode,” then establish radio or tethered communication so the rover can receive corrections. If the device supports Michibiki CLAS, enable the setting to receive satellite augmentation signals.

• RTK initialization: Once correction data reception begins, the rover’s GNSS receiver will start seeking an RTK solution. After a short time the solution stabilizes and a high-precision “fixed solution (Fix)” is obtained. The app displays the current positioning mode and accuracy indicators (e.g., horizontal error ◯ cm), allowing you to confirm that you can start surveying.

• Point measurement: Place the pole tip at the point to be measured and tap the “measure” button in the app. By standing still for a few seconds, the receiver continues to collect satellite signals and computes a high-precision coordinate, recording the point data. You can add point names or notes, or take a photo and attach it to the data. Important points can be measured multiple times and averaged to obtain more reliable values, as many systems stabilize accuracy by averaging signals from multiple satellites.

• Data saving and use: After measuring all required points, save the measurement data. Recorded coordinates are listed in the app and can be exported as CSV or DXF or uploaded to the cloud for sharing. Use the data for CAD drawings, as-built management reports, and other applications.

That is the basic flow. Once you master the steps, you will find positioning is much faster and simpler than traditional surveying.

Accuracy and reliability — How accurate is it?

How accurate are positions obtained by GPS surveying? In short, under good conditions horizontal positions can be within about ±1-2 cm (±0.4-0.8 in), and vertical positions within about ±3 cm (±1.2 in). This level of accuracy is far superior to single-receiver GPS (errors of 5–10 m) and is sufficiently reliable for construction and civil-engineering surveying. For example, when measuring ground elevations for as-built management, errors of only a few centimeters allow accurate calculation of earthwork volumes and precise control of structure placement.

However, these figures assume RTK corrections are functioning properly and satellite reception conditions are good. In areas with tall buildings or dense forests, satellite signals may be blocked or reflected (multipath), degrading accuracy. Atmospheric disturbances and ionospheric effects can also leave small residual errors, and vertical positioning tends to be more error-prone than horizontal. Even so, in somewhat adverse conditions you can often maintain accuracies on the order of tens of centimeters; except for extreme cases where RTK cannot be used at all (underground or inside tunnels), RTK is generally practical.

An important indicator of positioning reliability in RTK is whether a fixed solution (Fix) has been obtained. A Fix means the integer ambiguity resolution of the carrier-phase has converged, guaranteeing centimeter-level accuracy. Conversely, when the solution is unstable and ambiguities are being estimated as floating values, this is called a float solution (Float), and errors may range from tens of centimeters to about a meter. Modern surveying apps show “Fix” or “Float” so users can easily assess the trustworthiness of the current positioning result. Measuring in a way and in an environment that maintains a Fix solution ensures highly reliable coordinates.

To give concrete examples, some high-precision GNSS devices report a standard deviation of about 12 mm for a single-point standalone measurement, improving to about 8 mm when averaged over 60 seconds. Comparisons between small handheld GNSS receivers and expensive Class-1 GNSS survey instruments have shown differences of less than 5 mm at the same point. Recent devices are highly capable, and when used correctly they can achieve accuracies comparable to traditional large surveying instruments.

The important point is to operate equipment properly and manage positioning quality on site. For those new to GPS surveying, it is recommended to measure a known point (a control point with known coordinates) to confirm the typical error you get. If measurements show almost no error, the environment and settings are good; if you see offsets of several centimeters, you may need to improve satellite reception or remeasure. Fortunately, apps show satellite counts and geometry (DOP values), which you can use as references to make appropriate judgments and maintain GPS surveying accuracy and reliability.

Not just outdoors — positioning technologies usable in indoor and mountainous areas

Because GPS uses satellites, basic positioning is possible only outdoors with a view of the sky. However, technologies are being developed to expand the usable range beyond just outdoors. In Japan in particular, the Quasi-Zenith Satellite System (QZSS) has made GNSS more usable in mountainous areas and urban canyons.

First, consider mountainous areas. Traditionally, in remote mountain sites where network RTK corrections could not be received, high-precision positioning was difficult. Japan’s Quasi-Zenith Satellite “Michibiki” and its centimeter-class augmentation service (CLAS) provided by the Ministry of Land, Infrastructure, Transport and Tourism allow direct reception of RTK-type correction signals from satellites. In other words, even in locations without mobile coverage, if the sky is open you can achieve centimeter-class positioning using satellite signals and satellite-provided corrections alone. Because Michibiki stays longer over the Japanese sky, a satellite is often near zenith even in valleys, which helps stabilize positioning compared to GPS alone. Using multi-GNSS receivers that support GLONASS, Galileo, BeiDou, etc., increases the number of visible satellites and makes it easier to maintain an RTK solution in mountainous terrain.

Indoor positioning remains a major challenge for GNSS. Inside buildings or tunnels, satellite radio waves do not reach directly, so GPS surveying is basically not possible there. However, solutions that seamlessly bridge indoor and outdoor environments have begun to appear. For example, obtaining a high-precision GNSS position near a building entrance and then using smartphone AR (augmented reality) and inertial sensors to track indoor movement can maintain relative positioning for short periods indoors. This allows you to infer interior point locations relative to the reference obtained at the entrance and create drawings even if you cannot place an antenna directly inside. Additionally, techniques that combine smartphone cameras and GNSS to obtain coordinates of targets in photos are being commercialized; for example, by photographing a point inside a building through a window, you can estimate the wall point’s coordinates from the known camera position (via GNSS) and image angles. These indirect methods using image processing and sensor fusion are expanding the possibilities for obtaining coordinates in places where an antenna cannot be placed directly.

Complete indoor positioning still requires other technologies such as ultra-wideband (UWB) or Wi‑Fi positioning, but by using GNSS-derived control points for indoor tasks, high-precision location information is being extended to places that were previously difficult to measure. Going forward, the number of use cases for position information both outdoors and indoors will continue to grow.

How to use surveying results — cloud, AR, point-cloud scanning, and other examples

Data obtained by GPS surveying can be used not only as a list of coordinates but also in various other forms. The strong compatibility with digital technologies is another attractive feature of GPS surveying. Below are some use cases.

• Shared management via cloud: By uploading measured coordinates and site photos to a cloud platform, office staff can share information with on-site teams in real time. For example, measured points appear on a map immediately, and supervisors or designers in the office can check the data. You can overlay drawings in the cloud to verify completeness of measurements, reducing reliance on handwritten field books and significantly improving data management efficiency.

• AR-based site visualization: Combining surveying data with AR enables intuitive on-site visualization. You can display virtual flags or labels at measured points for setting out, or overlay a 3D model of the design on the actual ground to check the completed appearance. Information that used to be viewable only in drawings can now be projected into the real world through a smartphone or tablet, helping prevent construction errors and making explanations to stakeholders much easier. RTK-grade coordinates make accurate alignment in AR possible.

• 3D point-cloud scanning: Modern smartphones and dedicated devices often include LiDAR sensors or high-resolution cameras to record surrounding structures and terrain as point-cloud data. Combining this with GPS surveying allows you to georeference the captured point cloud and generate an as-measured 3D model. This can be used to scan pre-excavation terrain for volume calculations or to record the shape of structures during construction for as-built management. Point clouds provide highly detailed 3D information enabling arbitrary cross-section views and measurement of distances and areas later. Tasks that previously required specialized 3D scanners or drones are increasingly doable with handheld devices.

• Photo and video records: High-precision location information is useful for documenting site conditions with photos and videos. Apps integrated with GPS surveying can tag photos with the shooting coordinates and camera orientation. If you plot those photos on a map in the cloud, you immediately know where each photo was taken. You can track site changes over time with geo-tagged photos or use them as evidence for as-built inspections. Videos recorded while moving can leave a track log, allowing later review as GPS-data-tagged videos.

As these examples show, GPS surveying data is not just a collection of numbers but generates various added values when integrated with digital tools. Using survey results as cloud data, AR, and 3D models speeds up information sharing and analysis on site and contributes to the DX (digital transformation) of construction workflows.

Case study: How LRTK surveying is changing the site landscape

Finally, as a practical example of using modern GPS surveying devices on site, we introduce our product LRTK. LRTK is a compact RTK-GNSS receiver that pairs with a smartphone; weighing approximately 165 g, it is lightweight yet enables centimeter-level positioning (cm level accuracy (half-inch accuracy)) and functions as a versatile surveying device. It embodies the concept of “GPS surveying that anyone can do,” and its introduction illustrates how workflows on site are changing.

For example, on a certain road construction site, as-built measurements that previously required a team of surveyors to spend a full day setting up a total station can now be completed quickly by the site supervisor using LRTK. In the morning, the supervisor takes the LRTK device from a pocket, mounts it on a dedicated pole, and connects to a smartphone. Within a few minutes the device achieves an RTK Fix, and the supervisor simply walks around and presses a button at the points to be measured. Because the data syncs to the cloud immediately, the office PC shows measured points plotted on a map and work on creating as-built drawings can begin at once. Processes that used to wait for survey results and drawing the next day are now progressing in real time.

In another example, a local government used LRTK at a landslide site caused by heavy rain; staff were able to perform same-day measurements and quickly grasp the extent of the collapse and volume of soil. Tasks that would previously have required specialist contractors could be performed rapidly by the staff themselves, greatly improving initial response speed. This example was featured on television news and drew attention as a new surveying style that overturns the traditional image of “surveying.”

LRTK’s strengths combine the high accuracy, ease of use, and multifunctionality discussed earlier. It is easy for one person to carry and measure with a single button on site, yet the data accuracy rivals conventional surveying instruments. Measured data syncs to the cloud and provides one-tap access to features such as 3D scanning and AR display. It is truly a tool for the “democratization of surveying,” and widespread adoption of devices like LRTK will significantly change how surveying is performed.

As GPS surveying equipment that anyone can use becomes available, the utilization of position information is entering a new stage. If you have felt that “GPS surveying is difficult for me,” modern tools like LRTK can completely change that impression. Bring high-precision positioning closer to your daily work and give it a try on site.