Table of Contents

• What is point cloud data? Why it’s attracting attention on site

• Easy 3D scanning with iPhone LiDAR

• Centimeter-level accuracy achieved with RTK positioning

• Expanding field measurement with iPhone + RTK integration

• How compact, high-precision RTK terminals are changing worksites

• Accelerating data sharing and DX with cloud integration

• Smartphone surveying that’s easy for beginners

• Simple high-precision surveying with LRTK

• FAQ

What is point cloud data? Why it’s attracting attention on site

In recent years, the term “point cloud data” has become common on construction and surveying sites. Point cloud data are three-dimensional datasets that record the surfaces of objects or terrain as a dense collection of points. They are acquired using technologies such as laser scanners and photogrammetry, and each point contains X, Y, and Z coordinate values (and sometimes color information). By processing this vast collection of points, it is possible to reproduce a site as a realistic 3D model, almost like a photograph.

Traditionally, obtaining such high-precision 3D point cloud data required specialized surveying instruments or large laser scanners, involving significant effort and cost. However, driven in part by initiatives like the Ministry of Land, Infrastructure, Transport and Tourism’s “i-Construction” promotion of 3D measurement, demand for using point cloud data in civil engineering and construction is rapidly increasing. Point clouds are becoming key to on-site digital transformation (DX): recording as-built surveys in detail after construction, tracking progress during works, and comparing aging for infrastructure inspections.

The advantages of point cloud data lie in intuitive 3D visualization and rich informational content. Displaying acquired point clouds on a screen lets you inspect a site in a three-dimensional view as if you were there. Even novice workers or clients can grasp the overall spatial situation at a glance. On point clouds you can freely measure distances, areas, or volumes, dramatically improving measurement efficiency compared with traditional 2D drawings or photographs. Once acquired, point cloud data are stored as a “digital copy” of the site, so if you later realize “I should have measured that part,” you can check required dimensions on the data without returning for additional measurements. For these reasons, point cloud data are revolutionizing site recording and management methods.

Easy 3D scanning with iPhone LiDAR

Recently, it has become possible to acquire 3D point clouds with everyday smartphones, without special equipment. A prime example is the LiDAR sensor built into higher-end models of the iPhone. LiDAR is a technology that uses infrared lasers to rapidly measure distances to objects and was originally used in surveying laser scanners. Since the iPhone 12 Pro, this compact LiDAR has been integrated into iPhones, and using dedicated apps you can scan room interiors or nearby structures simply by pointing and walking around, capturing the surrounding geometry as point cloud data. It’s a groundbreaking feature that lets you record a 3D model as easily as shooting a video with your phone.

However, standalone smartphone LiDAR scanning has several limitations. First is the issue of positioning accuracy. The iPhone’s internal standard GPS can have errors on the order of meters, so the absolute coordinates of the acquired point cloud are not accurate. For example, you might scan an entire building but not know precisely where that data sits within a real-world coordinate system. Also, when scanning large areas, errors in the phone’s self-position estimation (so-called AR tracking from internal sensors) can accumulate and distort the geometry. Thus, while point clouds acquired by a smartphone alone are convenient, their absolute accuracy and reliability are problematic for direct use in surveying applications.

Centimeter-level accuracy achieved with RTK positioning

A technology attracting attention to compensate for weaknesses of smartphone LiDAR alone is RTK positioning. RTK (Real Time Kinematic) refers to a method that applies correction information to satellite positioning (e.g., GNSS) to significantly reduce positioning errors in real time. By receiving satellite signals simultaneously at a reference station and a rover, and sending error information computed at the reference station to the rover, the rover’s position can be enhanced to within a few centimeters of accuracy. In Japan, correction services such as Michibiki’s (Quasi-Zenith Satellite System) “centimeter-level positioning augmentation service (CLAS)” are available via the internet or satellite, making centimeter-level positioning—previously only achievable with specialized surveying instruments—more accessible.

Recently, small GNSS receivers that enable RTK on smartphones have emerged. Attachable GNSS receivers for phones and tablets can be paired with a smartphone so that high-precision position coordinates are added to the data being acquired in real time on the phone. For example, when an RTK-capable receiver is connected to an iPhone and receives correction information while positioning, the mode can become “Fix” within tens of seconds, allowing you to determine the current location with horizontal accuracy around ±2 cm. The smartphone app displays current positioning accuracy and satellite counts, letting you confirm sufficient precision while measuring. In this way, RTK transforms a smartphone into a high-precision GNSS surveying instrument.

Expanding field measurement with iPhone + RTK integration

What becomes possible when combining the iPhone’s LiDAR function with RTK positioning? The answer is that anyone can perform high-precision 3D point cloud measurements with inexpensive equipment. By linking the global coordinates obtained via RTK to each point of a point cloud captured by the smartphone LiDAR, the scanned data immediately acquire accurate latitude, longitude, and elevation information. In other words, a 3D model scanned with an iPhone can be directly overlaid onto real-world coordinate systems such as public coordinate systems.

This enables high-precision 3D surveying that previously required specialists or expensive equipment to be completed with just a smartphone. For example, calculating the volume of excavated soil at a construction site used to require a surveying team to measure the terrain and compute volumes, taking time. With iPhone + RTK, a site supervisor can scan excavated areas on the spot and instantly compute volumes from the point cloud data. Likewise, tasks such as monitoring displacement of completed structures or recording road surface conditions can be carried out by anyone on site without waiting for specialized equipment. In the 2020s, solutions combining smartphone LiDAR and RTK-GNSS to produce high-precision point clouds aligned to public coordinates have appeared, beginning the democratization of surveying. The fusion of smartphones and RTK is greatly expanding the possibilities of field measurement.

How compact, high-precision RTK terminals are changing worksites

Using compact RTK receivers integrated with smartphones dramatically changes surveying workflows on site. Here are several key reasons:

• Outstanding portability for measurements anytime: These devices are so small and lightweight they can fit in a pocket and don’t burden the phone when attached, allowing field workers to carry them constantly and use them for everyday surveying. Situations that previously required waiting for a surveying team can now be addressed immediately by taking out a phone and starting measurements, eliminating work delays.

• Centimeter-level positioning available instantly: Once powered on and satellites are acquired, high-precision coordinates can be obtained in real time. When a fixed solution (Fix) is achieved, you can record the current coordinates in seconds, allowing immediate staking out of reference points or elevation checks. Dedicated apps can average multiple positioning readings to further improve accuracy, and single-point positioning has been confirmed to stay around 1 cm in some cases.

• Cost reduction and productivity improvement: Using smartphones reduces costs compared with dedicated instruments, making it economically feasible to equip all site staff. When each worker has a surveying device, waiting time for surveying is reduced and multiple locations can be measured in parallel, dramatically increasing overall site efficiency. Cloud integration also allows data captured on site to be shared immediately within the company, streamlining reporting and review processes.

• Multipurpose functionality in one device: The appeal of a smartphone-integrated RTK is that it’s not limited to GNSS positioning. Combined with the phone’s camera and LiDAR, it enables photogrammetry and point cloud scanning as well. For example, taking geotagged site photos lets you later verify dimensions and positions in the office, and point clouds from LiDAR scans can be used for volume calculations and drawing creation. With one device you can handle “positioning,” “photo documentation,” “3D scanning,” and “AR visualization,” making it truly an all-purpose surveying tool for the field.

With the introduction of small RTK terminals, surveying that once required carrying heavy equipment can be transformed. A new era has arrived where strolling around a site with a smartphone and a compact device enables diverse high-precision data acquisition.

Accelerating data sharing and DX with cloud integration

Positioning and point cloud data obtained with smartphone + RTK can be used seamlessly with cloud services. After measurements on site are complete, survey data can be uploaded to the cloud from the app with one tap. If there is network coverage, data can be shared from the site to office staff immediately, and remote engineers can view point clouds and coordinate data via a web browser. Even if you collect data in areas without radio coverage—such as mountainous or underground locations—you can upload later once you reach coverage and share it via the cloud.

Once data are in the cloud, office teams can immediately start detailed analysis and review. Uploaded point clouds can be imported into dedicated point cloud processing or CAD software to create terrain models or check as-built conditions against design data. Single-point positioning data can be displayed on cloud maps for management, enabling swift reflection in surveying plans and as-built management documents.

This site → cloud → office data flow drastically shortens the traditional process of “survey, drafting, review, and feedback,” which used to take days. In some cases, stakeholders can share data the same day, discuss issues, and issue instructions for additional measurements. In disaster response, for example, field workers can record damage as point cloud data with smartphone + RTK and immediately share it via the cloud. Collecting and leveraging near-real-time 3D data from the field greatly accelerates decision-making and response.

Smartphone surveying that’s easy for beginners

Another advantage of smartphone + RTK surveying is its usability. Traditional surveying instruments required specialized training, but smartphone-based surveying follows app-guided prompts and is intuitive. For example, anyone can reach a target point by following arrows displayed on the phone screen, and point cloud scanning is as simple as moving the phone while “rotating” the camera. Some field workers are able to operate the system without prior training, and users comfortable with smartphones can learn quickly.

Smartphone apps present information clearly in Japanese, with positioning status and accuracy shown via icons and numbers at a glance. If users get stuck, help functions and support are available. Tasks that once relied on veteran surveyors can now be handled by anyone on site with smartphone surveying. Being usable without advanced expertise helps address labor shortages and technical succession issues. In terms of ease of use, smartphone + RTK is a solution well-suited for field deployment.

Simple high-precision surveying with LRTK

As a concrete solution for high-precision surveying that combines smartphones and RTK, there is the LRTK series developed by a domestic startup. LRTK is an all-in-one system consisting of a compact high-precision GNSS receiver for attaching to an iPhone (LRTK Phone), a dedicated smartphone app, and cloud services. This single package enables the aforementioned capabilities seamlessly—from centimeter-level positioning to point cloud scanning, photo-based measurement, and cloud sharing.

With LRTK, the receiver supports Michibiki’s CLAS, allowing centimeter-level positioning even when operating standalone outside of network coverage. It also includes linked cloud data management features so information acquired on site can be shared internally in a one-stop workflow. Initial setup and operation training support are provided, so those unfamiliar with surveying instruments can introduce the system with confidence.

We recommend requesting materials from the official website first to check detailed product information and case studies. By actually using LRTK on site, you can quickly adopt the new norm of “one high-precision surveying device per person,” gaining an early advantage in productivity improvements and quality control. With LRTK, which balances ease of use and high precision, start the next generation of simplified surveying.

FAQ

Q: Why is LiDAR scanning with a smartphone alone insufficiently accurate? A: The GPS built into smartphones has errors on the order of meters, so LiDAR-acquired point cloud data will have absolute position offsets. Also, the phone’s internal gyro and camera-based self-position estimation are not perfect, so scanning wide areas can result in distorted geometry. Using RTK together compensates for these positional offsets and distortions, allowing accurate coordinates to be assigned to point clouds.

Q: Does RTK positioning require a base station? A: It is not always necessary to set up a dedicated base station. In Japan, you can obtain high-precision correction information via the Internet using services such as Michibiki’s CLAS or public control point information services. Therefore, a standalone receiver and smartphone are sufficient for high-precision positioning. Of course, you can also operate your own base station (a reference station communicating with a rover), but in typical field scenarios existing correction services are adequate.

Q: Which iPhone models are supported? A: RTK receivers for smartphones, including LRTK, generally connect to iPhones or iPads via Lightning or USB-C connectors. LiDAR scanners are built into higher-end models such as iPhone 12 Pro and later (and corresponding iPad Pro models). LiDAR-equipped models are preferable to fully utilize point cloud scanning, but for GNSS positioning alone you can use non-LiDAR models for geotagged photo capture or single-point surveying.

Q: Can measurements be taken in bad weather or environments with obstacles? A: GNSS positioning performs best in open-sky environments. In forests or urban canyons the satellites may be obstructed and accuracy can degrade, but LRTK receivers are designed with high sensitivity for relatively stable positioning. Rain itself does not greatly affect positioning, but check whether your phone and devices are waterproof. LiDAR scans can be used at night or in dark spaces, but strong direct sunlight may introduce sensor noise. With appropriate environments and measurement techniques, these systems can be used in a variety of field conditions.

Q: What is the accuracy and density of point cloud data? A: Point density from iPhone LiDAR is coarser compared with professional laser scanners, typically on the order of several-centimeter spacing. However, this is sufficiently precise for construction management tasks such as shape recognition and volume calculation. Dimensional measurement errors remain within a small range. Scanning from multiple directions and merging point clouds can fill gaps and improve accuracy. The important point is that reliability of position is ensured by RTK, allowing multiple measurements to be combined into a consistent 3D model. While professional equipment may offer higher resolution, smartphone-based data are sufficiently practical for everyday field operations.