With LRTK Phone Accuracy, Smartphone AR Point Cloud Scanning Can Be This Accurate!

Table of Contents

• What is LRTK Phone accuracy? Centimeter-level positioning achievable with a smartphone

• Accuracy and challenges of conventional smartphone AR point cloud scanning

• How LRTK Phone improves accuracy

• Comparison with professional surveying equipment: the capability of LRTK Phone accuracy

• Possibilities opened by higher-accuracy smartphone point cloud scanning

• What “simple surveying” realized by LRTK can do

• Conclusion

• FAQ

What is LRTK Phone accuracy? Centimeter-level positioning achievable with a smartphone

LRTK Phone is a revolutionary system that enables centimeter-level high-accuracy positioning using only a smartphone (especially iPhones). Normally, smartphone GPS positioning accuracy is said to be on the order of several meters (a few ft), but with LRTK Phone you can determine position with surveying-equipment-grade accuracy—errors of only a few centimeters (a few in). This is realized by a dedicated ultra-compact GNSS receiver that leverages the positioning technique RTK (Real-Time Kinematic), together with a smartphone app and cloud service. By simply attaching a small, pocket-sized device to your phone, you can obtain position information with accuracy comparable to expensive surveying instruments.

This “cm level accuracy (half-inch accuracy)” allows accurate coordinates to be attached to any data captured by a smartphone. For example, if you scan the surroundings with an iPhone’s built-in LiDAR sensor or AR functions, you can assign latitude, longitude, and elevation in a geodetic coordinate system to the acquired point cloud. Before LRTK Phone, point clouds scanned with a smartphone only had relative coordinates, and aligning them to actual site coordinates required additional adjustments. By using LRTK Phone’s high-precision positioning information, smartphone AR point cloud scans can be given absolute (global) coordinates, enabling 3D data acquisition with scale and spatial relationships that match the real site exactly.

Accuracy and challenges of conventional smartphone AR point cloud scanning

3D scanning using smartphone AR technology has attracted attention as an easy way to acquire on-site three-dimensional data. However, conventional smartphone AR point cloud scanning has had several accuracy-related challenges. Specifically, the following issues were problematic:

• GPS accuracy limits: Typical built-in smartphone GPS generally has errors on the order of several meters (a few ft), which is insufficient for surveying large sites or precise alignment. Even when plotting on a map, deviations of several meters (a few ft) can occur, making accurate location records difficult.

• Accumulation of AR scan errors: Smartphone AR scans (e.g., iPhone LiDAR scans) acquire point clouds while estimating the device’s position using the device’s IMU sensors and camera. Therefore, as travel distance increases, errors gradually accumulate, potentially causing distortion or scale mismatch in the scanned 3D model. In some cases lengthwise or heightwise errors of a few percent can occur, posing problems where precision is required.

• Lack of absolute coordinates: Scan data from a smartphone alone is basically recorded in a local coordinate system (relative coordinates valid only for that session). When overlaying with other survey data or design drawings later, manual transformation and alignment to reference points are required, which is time-consuming. In surveying applications in particular, the inability to acquire data in an absolute coordinate system such as national geodetic coordinates was a major limitation.

As described above, because of its ease of use, smartphone AR point cloud scanning has had accuracy limits, and the conventional wisdom has been that it is useful for simple records and visualization but difficult to use for rigorous surveying.

How LRTK Phone improves accuracy

LRTK Phone technology solves these issues and dramatically improves the accuracy of smartphone AR point cloud scanning. Let’s look at how LRTK Phone achieves high accuracy.

1\. Centimeter positioning with RTK-GNSS: LRTK Phone is equipped with a high-performance GNSS receiver that acquires signals not only from GPS but from multiple satellite positioning systems (GNSS). It receives real-time correction information from a base station via the RTK method, greatly reducing positioning errors. As a result, in open-sky environments LRTK Phone reaches a “Fix” solution in about 20–40 seconds and can determine the smartphone’s position with astonishing accuracy of approximately ±2 cm (±0.8 in) horizontally and ±4 cm (±1.6 in) vertically. Conventional smartphone GPS accuracy of about ±10 m (±32.8 ft) can thus be improved by orders of magnitude through RTK.

2\. Integration with the smartphone’s AR features: The high-precision position information from LRTK Phone is integrated into the smartphone’s AR engine (e.g., iPhone’s ARKit). This ensures that the device maintains an accurate real-world self-position while moving through space. Normal AR scans can incur slight errors in self-position estimation, but by adding LRTK correction data, device tracking becomes much more accurate and point cloud distortion or scale mismatch is greatly reduced. In other words, each point captured by the phone’s camera or LiDAR is mapped to the correct geographic coordinate in real time.

3\. Acquisition of point clouds with absolute coordinates: With high-precision positioning combined with AR, point clouds scanned by the smartphone are recorded from the start with absolute coordinates (based on a geodetic datum, for example). This produces 3D data that can be used as survey deliverables on the spot without special calibration work. For example, when scanning terrain or structures, the point cloud can immediately be overlaid with maps or CAD design data for analysis, dramatically improving post-processing efficiency. Additionally, acquired point clouds can be checked in real time on the smartphone, allowing operators to add scans in missing areas as needed and verify data quality on site.

4\. Dedicated app and cloud services: The LRTK Phone system includes a dedicated iPhone app and a cloud service (LRTK Cloud) for data management and processing. The app provides an intuitive UI for one-stop operations from starting positioning to point cloud scanning and AR display. On the cloud, uploaded point cloud data can be viewed on a 3D map, measured for distance/area/volume, and compared with design models. This software support enables immediate use of the high-precision data captured on site.

Through this hardware–software integration, LRTK Phone dramatically improves the accuracy and practicality of smartphone AR point cloud scanning.

Comparison with professional surveying equipment: the capability of LRTK Phone accuracy

Even if the principle promises high accuracy, you may wonder, “Can a smartphone really measure that accurately?” Let’s confirm LRTK Phone’s performance by comparing it with professional surveying equipment.

Internal and field tests have confirmed that the coordinates obtained with LRTK Phone are comparable to those obtained with a Class-1 GNSS receiver (survey-grade GPS) used by surveyors. Specifically, the same point was measured with both LRTK Phone and a Class-1 GNSS receiver, and the resulting coordinates were compared. The coordinate differences between the two were on the order of a few millimeters (with a maximum of less than 5 mm (0.20 in)) in both horizontal and vertical directions, falling within the margin of error and showing almost identical values. This means that the small device mounted on a smartphone achieves sub-centimeter-level accuracy comparable to professional surveying equipment.

In another test, known-point coordinates were measured dozens of times with LRTK Phone and the mean and variance were analyzed to evaluate stability. The result showed very little variation between measurements, the mean was extremely close to the theoretical value, and consistent high reproducibility was observed. This indicates that LRTK Phone does not just produce a single occasional high-accuracy reading, but maintains high accuracy consistently in repeated measurements.

Importantly, this accuracy can be obtained easily on site. Previously, centimeter-level positioning required large GNSS equipment mounted on tripods or total stations operated by specialized surveyors. LRTK Phone can extract equivalent accuracy from a smartphone-sized, one-handed device, lowering the barrier for field surveying. High accuracy combined with ease of use is the greatest strength of LRTK Phone.

Possibilities opened by higher-accuracy smartphone point cloud scanning

With LRTK Phone dramatically improving smartphone AR point cloud scanning accuracy, various applications that were previously difficult have become realistic. Here are some of the possibilities opened by this higher accuracy.

First, its use in civil engineering and construction sites is notable. Tasks that previously required surveying equipment—such as as-built measurements and pre/post-earthwork terrain surveys—can now be completed by walking the site with an LRTK Phone–equipped smartphone and scanning the point cloud. For example, even when calculating the volume of large embankments or excavations, accurate volume calculation is possible from a smartphone-scanned point cloud. Because the point cloud has absolute coordinates, it can be immediately compared with design cross-sections or reference elevations, allowing on-the-spot decisions about how much material to add or remove. LRTK Phone is ideal for routine as-built control; measurements that used to be outsourced to specialists can now be performed frequently by in-house staff, greatly improving progress management and quality checks.

Next, possibilities expand for infrastructure inspection and disaster sites. Because high-precision 3D point clouds can be obtained easily, smartphones can be used for displacement measurement of bridges and tunnels, slope collapse assessment, and more. For example, in the immediate aftermath of a disaster, using LRTK Phone–equipped smartphones allows rapid acquisition of detailed 3D data without survey teams spending long periods in dangerous areas. Acquired data can be shared via the cloud instantly, enabling remote experts to collaborate in real time and devise swift response measures. The ability to complete initial response surveying and recording with a single smartphone is a major advantage.

Furthermore, combining with AR technology creates new possibilities. When AR accuracy was poor, overlaying virtual design models on site suffered from large misalignments, limiting practicality. With LRTK Phone, BIM/CIM models and other digital data can be displayed precisely aligned with the real environment. This allows on-site verification of completed imagery in true scale and correct position—that were previously only visible on design drawings or 3D models. Applications such as AR-based design visualization or AR display of buried utilities to assist excavation work will expand rapidly. Accurate AR helps reduce construction mistakes and improves on-site sharing of design intent, making it a key tool in construction DX (digital transformation).

Thus, higher accuracy in smartphone AR point cloud scanning not only improves the technology itself but has the potential to transform on-site workflows. Affordable and easy-to-use tools that make high-quality 3D data accessible to anyone allow tasks once left to specialists to be carried out in-house, speeding decision-making and cutting costs.

What “simple surveying” realized by LRTK can do

LRTK Phone is not only about point cloud scanning with smartphones; it is also a trump card for “simple surveying” that makes various on-site measurements easy. Traditionally, surveying required specialized equipment and advanced skills, but with LRTK, field staff can complete minor measurements on their own on the spot.

Here are the main capabilities of simple surveying with LRTK:

• One-touch point surveying: With LRTK Phone attached to a smartphone, you can record the coordinates of a specific point with a single tap. If the positioning status is Fix, the obtained coordinates have errors of only a few centimeters (a few in) in latitude, longitude, and elevation. For example, boundary points or arbitrary feature locations can be measured accurately by a single person approaching and recording them.

• Distance and area measurement without a tape: The dedicated app allows immediate measurement of distances between two points or areas enclosed by polygons using on-site point clouds or photos. There is no need to pull out a tape measure or perform manual survey calculations. Tap the necessary points on the smartphone screen and highly accurate lengths and areas are calculated automatically.

• Immediate volume and earthwork calculation: You can calculate the volume of embankments or excavations from point cloud data on the spot. For example, to estimate the amount of excavated soil from earthwork, scan around with your smartphone, upload to the cloud, and in a short time you can obtain an accurate soil volume. This enables immediate decisions on truck allocation and soil disposal plans.

• Stakeout and positioning navigation: The LRTK app includes a “coordinate guidance (stakeout)” function that guides the user to a specified coordinate. When approaching a pre-set target point, the remaining distance is displayed in centimeters and the app notifies you when you reach the precise location. This allows tasks that previously required two people—such as stakeout using a total station for angle and distance guidance—to be performed solo with a smartphone. Using AR display, you can also show a 3D flag or marker model at the target point for visual guidance.

• Geotagged photo records: Photos taken with the smartphone can be tagged with high-precision position and orientation information. When reviewing photos later, you can accurately know “where and which direction the photo was taken,” which is useful for reporting and time-series comparisons. The cloud also supports plotting photos on a map for an at-a-glance view of shooting locations.

With LRTK Phone at the core, surveying and measurement tasks that once relied on specialists and costly equipment become remarkably accessible. “Measure on the spot whenever you think of it” becomes a reality, speeding decision-making and improving on-site autonomy. LRTK presents a modern, practical approach to simple surveying for today’s fieldwork.

Conclusion

We have examined in detail the accuracy of LRTK Phone, which is revolutionizing smartphone AR point cloud scanning, from its mechanisms to use cases. Realizing centimeter-level positioning with a smartphone and immediately assigning absolute coordinates to point cloud data is profoundly significant. LRTK Phone transforms the smartphone from a mere gadget into a full-fledged surveying tool, accelerating on-site digitalization and efficiency.

The combination of high accuracy and ease of use offered by LRTK Phone creates new opportunities across many spatial-data use cases beyond surveying and construction management. From precise point cloud scanning and simple surveying to AR visualization, tasks that were previously carried out separately can now be seamlessly linked with a single smartphone. If you want easier and more accurate on-site data capture or to promote DX in your operations, adopting smartphone surveying with LRTK is well worth considering. Experience the cutting-edge LRTK Phone accuracy for yourself.

FAQ

Q: What does LRTK Phone stand for?

A: “LRTK” is the name of our solution and refers to a high-precision positioning system that utilizes RTK (Real-Time Kinematic) technology. “Phone” indicates that it works in conjunction with a smartphone, hence the combined name LRTK Phone. The main difference from general GPS is that it dramatically improves positioning accuracy by using real-time correction information.

Q: What level of positioning accuracy can LRTK Phone achieve?

A: Under favorable conditions (open sky with sufficient satellite visibility) when an RTK fixed solution (Fix) is obtained, you can expect approximately ±2 cm (±0.8 in) horizontal accuracy and about ±4 cm (±1.6 in) vertical accuracy. Actual verifications have shown differences of only a few millimeters compared to professional surveying GPS, so the accuracy is practically imperceptible in many applications.

Q: How large an area can be scanned at once with smartphone point cloud scanning?

A: Smartphone AR scanning depends on the surrounding environment, but as a guideline you can continuously capture point clouds over ranges from tens of meters to hundreds of meters (tens of ft to hundreds of ft). Using LRTK Phone preserves positioning accuracy even when moving long distances, so, for example, you can walk along a slope about 200 m (656.2 ft) long and scan it in 1–2 minutes. For very large areas, you can divide the area and scan multiple times, then merge the data afterward.

Q: Do I need specialized knowledge or qualifications to use it?

A: No. Basic operations are completed within the smartphone app and it is designed to be intuitive so that users without specialized knowledge can handle it. Simply attach the LRTK Phone to your smartphone and press the app’s positioning start button to automatically begin high-precision positioning, then follow the prompts to perform scans and measurements. With a short training or by reading the manual, anyone on site can perform measurements with surveyor-like accuracy.

Q: Can it be used indoors or in areas without GPS signal?

A: In indoor locations or tunnels where GNSS signals cannot be received, real-time high-precision RTK positioning does not function. In those cases, relative measurements using the smartphone’s AR features alone are possible, but absolute coordinate accuracy is not guaranteed. However, you can compensate by using a previously obtained reference point to measure in a local coordinate system. Essentially, the technology is most powerful in open outdoor environments, but by adapting use to the environment it can still be useful in various scenarios.

Q: Which smartphones are supported?

A: Currently, the solution is for iPhone. In particular, iPhones equipped with a LiDAR scanner (iPhone 12 Pro and later models) can fully utilize the AR point cloud scanning features. Expansion of supported devices is being considered for the future, but the latest iPhones can use LRTK Phone functions without issue. The companion app is available on the App Store, so if you have a compatible iPhone you can immediately try high-precision positioning.