Table of contents

• What are LRTK LiDAR point clouds?

• Basics of LiDAR sensors and point clouds

• Integration of LRTK and LiDAR point clouds

• Thinking about the accuracy of LRTK LiDAR point clouds

• Points that make it easy for beginners to use

• Applications: AR and overlaying with drawings

• Use cases such as cloud sharing

• Benefits of adoption: accuracy, speed, visualization

• Advantages of simple surveying with LRTK and recommendations for adoption

• Frequently asked questions (FAQ)

What are LRTK LiDAR point clouds?

LRTK LiDAR point clouds are high-precision three-dimensional point cloud data obtained by combining 3D scans from LiDAR sensors with the high-accuracy positioning technology LRTK. LiDAR is a sensor that measures distances to objects using laser light, and its measurements are represented as a collection of countless points (a point cloud). Traditionally, acquiring accurate point clouds required expensive equipment such as dedicated 3D laser scanners. However, with LRTK LiDAR you can perform similar point cloud measurements easily using only a smartphone like an iPhone and a small device.

LRTK is our high-precision GNSS solution that realizes real-time kinematic (RTK) satellite positioning on a smartphone. By scanning the surroundings with the smartphone’s built-in LiDAR while combining centimeter-level position information obtained by the LRTK device, you obtain point clouds in which each point is assigned accurate coordinates such as latitude, longitude, and elevation. In other words, with LRTK LiDAR point clouds you can easily record site shapes as high-precision 3D data by yourself. This article explains the mechanism, accuracy, and adoption benefits of this technology in an easy-to-understand way for beginners.

Basics of LiDAR sensors and point clouds

A LiDAR sensor irradiates laser light onto an object and measures distance from the time it takes for the reflected light to return. For example, a smartphone’s LiDAR emits infrared laser pulses and rapidly measures the time until they bounce back from walls, floors, and so on. By this principle, LiDAR can acquire hundreds of thousands of distance data points per second and record them in three-dimensional space as a collection of points. This multitude of points is called a point cloud, and when you view point cloud data you can see the shape of the real space reproduced as a mass of points.

Each point in point cloud data has XYZ coordinates and can accurately represent the shape and size of objects. Unlike photos, point clouds allow you to measure dimensions at arbitrary locations afterward or create cross-sectional drawings. For this reason, point clouds are used in surveying and construction for recording terrain, construction management, and verification of as-built conditions, and they have attracted more attention recently in trends such as digital twins and i-Construction. Traditionally, terrestrial laser scanners and drone-mounted LiDAR were mainstream, but LiDAR sensors are now built into mobile devices like iPhones and iPads, making it easy to acquire surrounding 3D point clouds.

Integration of LRTK and LiDAR point clouds

3D scanning is possible with a smartphone’s LiDAR alone, but the resulting point cloud is recorded in the device’s internal relative coordinates and will not align with real-world map coordinates. The integration of LRTK and LiDAR solves this. By using the high-accuracy position information (latitude, longitude, elevation) obtained from the LRTK device, the smartphone continuously knows its position accurately while scanning. The acquired point cloud is assigned GNSS-derived accurate coordinates in real time, allowing the point cloud to be placed at the correct location in the site coordinate system or on a map.

In other words, LRTK acts as a reference for position, linking LiDAR point clouds to real-world coordinates. Previously, aligning point clouds to maps required installing known control points on site and manually registering them afterward. With LRTK LiDAR, that effort is unnecessary: from the instant of scanning the point cloud is placed directly on the surveying coordinate system. Data are saved in Japan’s plane rectangular coordinate system (surveying coordinates) and can be converted immediately to the World Geodetic System (WGS84) or any local coordinate system as needed. By combining LRTK and LiDAR, the workflow from point cloud acquisition to incorporation into drawings and maps becomes seamless.

Thinking about the accuracy of LRTK LiDAR point clouds

One of the defining features of LRTK LiDAR point clouds is their high positioning accuracy. While typical smartphone built-in GPS accuracy is about 5–10 m (16.4–32.8 ft), LRTK reduces errors to approximately ±1–2 cm (±0.4–0.8 in) horizontally and ±3 cm (±1.2 in) vertically. This dramatic improvement is because the LRTK device uses signals from multiple satellites and augmentation signals to cancel out error sources. In practice, comparisons between positions measured by an LRTK Phone and those measured with a high-end surveying GNSS receiver have shown differences of only a few millimeters, confirming accuracy comparable to professional equipment.

Meanwhile, the LiDAR sensor’s own measurement accuracy is also high, with a few centimeters accuracy at close range. An iPhone’s LiDAR has an effective range of only a few meters, but within that range it can capture wall irregularities and ground elevations to within a few centimeters. In LRTK LiDAR point clouds, the LiDAR’s shape-measurement accuracy and GNSS positioning accuracy are combined, enabling the conversion of site objects into 3D data with near-real-world precision. Elevation differences of terrain and structure heights can be captured accurately, and measurement in the vertical direction—which was difficult before—becomes easy. There have also been cases where positioning was achieved in mountainous areas where the sky is not completely open, and stable accuracy is maintained through environment-dependent optimization. However, note that positioning is difficult in places where satellite signals cannot reach, such as inside tunnels.

(When the text refers to centimeter accuracy, it means centimeter-level accuracy (cm level accuracy; half-inch accuracy).)

Points that make it easy for beginners to use

• Simple operation: Dedicated smartphone apps have intuitive UIs, and starting positioning or scanning point clouds can be done with a single button. Complex settings and calculations are processed in the background, making the system easy to handle even for beginners without surveying expertise.

• Compact equipment: The LRTK Phone device is compact enough to attach to a smartphone, weighing approximately 165 g and about 1 cm (0.4 in) thick. Heavy tripods and large equipment are unnecessary, and portability is simple with just a smartphone and a small device. It offers mobility in narrow sites and at height, allowing surveys to start immediately when needed.

• Solo operation: Traditional surveying sometimes required assistants, but with LRTK LiDAR point clouds all tasks can be completed by one person. By holding the smartphone or attaching it to a monopod (pole), you can take measurements and obtain coordinate-tagged point cloud data on the spot. This is especially valuable on sites with staff shortages or small-team surveys.

• Automated data processing: Point cloud merging, coordinate conversion, cloud storage, and other tedious data processing are automated. After measurement, results can be checked within the app, so you don’t need to perform complex post-processing back at the office. Acquired data can be shared to the cloud on-site or exported for CAD software as needed.

• Safe and secure: Because operation is simple, users are less likely to be confused on site and even first-time users can feel at ease. In dangerous slopes or disaster areas, point clouds can be acquired from a safe distance, enabling less-experienced technicians to measure without undue risk.

• Affordable adoption: LRTK solutions significantly reduce initial costs compared to expensive surveying equipment. If you already have a compatible smartphone, you can start with a small device and software. The low upfront investment makes adoption easier for individuals and small to medium-sized businesses.

Applications: AR and overlaying with drawings

High-precision data obtained from LRTK LiDAR point clouds is powerful when combined with AR (augmented reality) technology for on-site verification tasks. Through a smartphone screen you can overlay virtual 3D models or guideline graphics onto live views, allowing intuitive understanding of where and at what height designed structures will appear on-site. Thanks to LRTK’s high-accuracy coordinates, pre-aligning models is unnecessary, and the models are projected precisely without drift. For example, you can AR-display a planned building model on the spot to check the finished appearance, or show virtual lines on the ground to indicate excavation limits.

Using LRTK’s positioning guidance enables easy stakeout as well. If you input the reference point coordinates from drawings, AR targets or arrows are displayed on the screen and the worker simply follows the guidance to reach the exact point for staking. Unlike traditional methods that track angles and distances with surveying instruments or use tapes for measurement, intuitive on-screen guides make positioning quicker and reduce human error, shortening work time.

Acquired point clouds are also useful for overlaying with drawings and for drafting. If you import point clouds into the LRTK cloud or CAD software, you can compare measured point clouds and design drawings on the same coordinates. For example, you can overlay point clouds of completed structures with design models to verify differences, or create plans and cross-sections from ground point clouds. The LRTK system also offers features that automatically extract terrain contours from point clouds to generate drawings, enabling rapid drafting directly from site-acquired data. This bridges the gap between point cloud data and traditional 2D drawings and smooths the verification of design and construction consistency.

Use cases such as cloud sharing

LRTK LiDAR point clouds support cloud sharing, enabling smooth use of acquired data within and outside organizations. Point clouds, surveyed points, and photos uploaded from a smartphone on site are saved and shared in the cloud instantly over the internet. From an office PC, you can access and view 3D point clouds in a browser without installing dedicated software. In the cloud you can rotate and zoom point clouds while measuring distances and areas, and combine photos to understand conditions. Because everyone involved can view the same latest data, communication between site and office is significantly more efficient.

For example, suppose a field staff member performs a survey with LRTK LiDAR point clouds and synchronizes the data to the cloud. Managers or designers in a remote office can immediately view the 3D data, measure dimensions, and compare it to design drawings as needed. This allows accurate situation assessment and decision-making without visiting the site, speeding up decisions. In fact, local governments have used LRTK cloud sharing in disaster response. For example, during the Noto Peninsula earthquake, rapid 3D recording of affected sites and cloud sharing enabled remote teams to grasp damage details quickly and accelerate restoration planning. From routine construction management to emergency damage surveys, cloud integration further increases the value of LRTK LiDAR point clouds.

Benefits of adoption: accuracy, speed, visualization

By adopting LRTK LiDAR point clouds, you can gain significant benefits in accuracy, speed, and visualization as follows.

• Improved accuracy: Centimeter-level high-precision data minimizes previously overlooked offsets and errors. With accurate coordinate data available for comparison with design values and as-built inspection, construction mistakes can be detected and corrected early. Vertical checks that were previously difficult become easy, improving quality control. Also, by acquiring point clouds you avoid the risk of discovering missed measurement spots afterward, leaving a complete and reliable record.

• Speed-up: The time and effort required for surveying and measurement are greatly reduced. Point cloud measurement acquires many points at once, and tasks that previously took hours for as-built measurement can in some cases be completed in tens of minutes. Time spent on equipment setup and point reading is reduced, and single operators can move around sites quickly. Because data are shared to the cloud immediately after acquisition, reporting and drafting in the office proceed rapidly. Overall, lead times from survey to decision-making are shortened, improving project-wide efficiency.

• Visualization benefits: Because site conditions are visualized intuitively with 3D data and AR, information sharing and consensus building among stakeholders become smoother. For example, terrain undulations that are hard to convey with verbal descriptions or 2D drawings are immediately obvious in a 3D point cloud model. Presenting the finished image in AR helps gain understanding from clients and local residents. Visual comparison also enables early detection of discrepancies between design and construction, preventing rework. Such visualized data facilitates communication and ultimately raises project quality.

Advantages of simple surveying with LRTK and recommendations for adoption

LRTK LiDAR point clouds transform surveying work that previously relied on specialists into simple surveying that anyone can handle. The ease of obtaining high-precision 3D measurements with a single smartphone strongly supports on-site digital transformation (DX). In practice, adoption has spread widely across local governments and construction companies, producing results in disaster response, infrastructure maintenance, urban planning, and other applications.

Compared with traditional methods, LRTK LiDAR point clouds offer overwhelming efficiency and versatility, and are poised to become a standard surveying method for the future. The benefits of accuracy, speed, and visualization improve work quality and productivity, reduce on-site burdens, and help alleviate workforce shortages. If you feel challenges in improving site surveying efficiency or utilizing 3D data, consider adopting LRTK LiDAR point clouds. You may be surprised by their ease and effectiveness. Embrace these latest technologies and realize an update to your field operations.

Frequently asked questions (FAQ)

Q: What are LRTK LiDAR point clouds? A: They are three-dimensional surveying data that combine point clouds acquired by a smartphone’s LiDAR sensor with position information from high-accuracy GPS (LRTK). Since the point clouds measured by the phone’s laser are assigned coordinates with centimeter-level accuracy (cm level accuracy; half-inch accuracy), they can be used directly for precise site measurements and records.

Q: What do I need to use them? A: You need an iPhone or iPad equipped with a LiDAR sensor and a dedicated small GNSS receiver called the LRTK Phone. Install the LRTK dedicated app on these devices to use the system. Positioning is basically possible without network connectivity, but having a connection is convenient for cloud sync and map display. For more stable measurements it is ideal to have a monopod (pole) to fix the smartphone, though handheld use is also possible.

Q: Can it be used outside mobile network coverage? A: Yes. LRTK supports the centimeter-level positioning augmentation service (CLAS) provided by Japan’s quasi-zenith satellite system “Michibiki,” enabling high-accuracy positioning from augmentation signals alone in mountainous areas without cellular coverage. However, note that positioning is not possible in places where GPS signals themselves cannot be received, such as underground or inside tunnels.

Q: Can people without surveying expertise use it? A: Yes. It is designed for intuitive operation. On the smartphone app, simply press “Start positioning” or “Start scan” and point cloud acquisition and coordinate calculations are performed automatically. Complex settings and calculations are handled by the system, so users only need to follow on-screen instructions. Operation manuals and support are also available, so even first-time users can use it with confidence.

Q: In what fields and applications can it be used? A: There are many uses such as as-built management on construction sites, stakeout for foundations, quantity calculation for civil works (earthfill and excavation volumes), damage recording during disasters, and infrastructure maintenance (checking road collapses and measuring bridge displacements). In short, LRTK LiDAR point clouds are very useful wherever accurate recording and sharing of site shapes and positions are needed. Adoption is expanding across surveying, civil engineering, architecture, urban planning, agriculture and forestry, and disaster prevention.

Q: How does it differ from traditional surveying methods? A: Traditional methods measured points one by one with a total station or had meter-level errors with GPS, but LRTK LiDAR point clouds acquire a large number of points at high speed and high accuracy at once. There is no need to carry heavy tripods or prisms, and surveying can be completed with just a smartphone and a small device. Also, results are generated as 3D data on site, reducing post-processing effort and allowing immediate use as explanatory materials. In short, the same surveying work achieves a different level of efficiency in terms of speed, accuracy, and information volume.

Q: Can I create drawings from point cloud data? A: Yes. Point cloud data acquired with LRTK can be exported in common point cloud file formats and imported into CAD/BIM software such as AutoCAD and Revit for drawing and model creation. The LRTK cloud also provides functions like cutting cross-sections and automatically extracting terrain contours to generate DXF drawings. In other words, once you have point clouds, you can smoothly create traditional plans and cross-sections, improving efficiency in design and report preparation.