All-in-one GNSS Rover Debuts! From Point Cloud Measurement to AR — Completed on a Smartphone

Introduction: Where GNSS Rovers Are Taking Construction Surveying Today

Surveying technology at construction sites is now at a major turning point. Until recently, high-precision GNSS rovers for positioning and 3D laser scanners for terrain point cloud measurement required separate, expensive equipment and specialized skills. However, with the advent of the all-in-one GNSS rover, an era is beginning in which positioning, point cloud measurement, and even site visualization via AR (augmented reality) can be handled end-to-end on a smartphone. For example, in the latest systems, with only a few minutes of instruction you can take pocket-sized equipment out and, with one hand, obtain high-precision point cloud data with position coordinates. In recent years, innovations in on-site surveying and measurement have progressed rapidly, such as creating high-precision point clouds of sites using iPhones or iPads, or measuring point cloud data in public coordinate systems with GNSS. This article explains in detail for surveyors and ICT construction personnel how this smartphone-complete next-generation GNSS rover is changing construction surveying, focusing on keywords like “point cloud measurement,” “AR utilization,” and “cloud integration.”

What Is a Smartphone-Complete GNSS Rover?

A smartphone-complete GNSS rover is, in short, a smartphone-integrated high-precision positioning system. Rather than traditional surveying instruments, a small GNSS receiver that fits in your pocket is attached to a smartphone, and RTK positioning and 3D measurement are performed via a dedicated app. This system enables centimeter-level positioning such as horizontal accuracy ±2 cm (±0.8 in) and vertical ±4 cm (±1.6 in), and the acquired coordinates can be checked on the spot against maps or drawing data on the smartphone. Its intuitive smartphone interface makes it easy for anyone to operate, so even non-specialist personnel can complete on-site surveying alone — a revolutionary change. Moreover, because the smartphone itself provides technologies such as cameras, LiDAR scanners, and AR display functions, it can perform not only simple positioning but also 3D scanning and overlaying virtual objects all in one.

An example of a GNSS rover device attached to a smartphone. It is lightweight at about 165 g and is a device (LRTK Phone) with the antenna and battery integrated, attached to an iPhone for use. It extends the smartphone’s GPS functionality to enable high-precision positioning, allowing surveying and point cloud scanning to be performed while walking with the smartphone in one hand.

Point Cloud Measurement for “Measure and Use Immediately” Construction Management

One major benefit of the all-in-one GNSS rover is that it makes on-site point cloud measurement part of everyday construction management. Traditionally, obtaining detailed point cloud data of existing terrain required expensive 3D laser scanners and complex data processing, making frequent use impractical. With a smartphone-integrated GNSS rover, however, you can combine an iPhone’s built-in LiDAR scanner and RTK-GNSS positioning to easily acquire 3D point cloud data on site. Simply walking while pointing the smartphone like you would when shooting video allows anyone to scan an area of about 100–200 m (328.1–656.2 ft) in a short time, and the acquired point cloud data is already tagged with high-precision position coordinates.

Because the point cloud data is acquired in absolute coordinates, it can be used on the spot for comparisons with design data and quantity calculations. For example, uploading point clouds to a cloud-based 3D viewer allows you to check terrain elevations and cross sections or measure distances and areas without specialized software. The difference in volume between the as-built (actual embankment or excavation) and the design model can be calculated immediately, letting you see at a glance how much soil needs to be added or removed to meet the design. This “measure and use immediately” point cloud measurement enables tasks that were previously performed after construction—such as as-built management and quantity checks—to be carried out quickly during the work process.

AR Utilization Visualizes Site Management

The use of AR (augmented reality) dramatically advances on-site visualization. Because design drawings and 3D models can be overlaid on the real scenery through the smartphone screen, information that is hard to intuit from paper drawings or numbers can be “seen” and confirmed on site. For example, when staking out foundation positions, the traditional method required measuring multiple reference points from drawings and repeatedly checking for errors, but using AR you can display the building’s design model and on-site reference points simultaneously to instantly see whether each point is displaced. Human errors that often occur with checks relying solely on numeric verification can be greatly reduced through AR’s visual confirmation.

Point clouds and coordinate data obtained with the smartphone GNSS rover deliver further benefits when combined with design information for AR display. For instance, if you upload drawing data (DWG, etc.) to the LRTK cloud, you can overlay and check those drawings on the real object through the smartphone screen in the field. This makes it intuitive to understand where design lines and positions correspond on site and helps confirm locations of buried utilities and inspect as-built conditions. AR visualization deepens common understanding among site stakeholders and is expected to streamline progress reporting and explanations to clients. In one proof-of-concept by a major construction company, the introduction of an AR system reportedly reduced the time required for building layout and reinforcement inspections by about 56% compared with conventional methods, demonstrating a remarkable productivity improvement.

Centralized Management of Drawings, Photos, and Point Clouds via Cloud Integration

Survey data collected on site can be shared instantly with the office and stakeholders through cloud integration, enabling centralized management of drawings, photos, and point clouds. If you upload coordinate data, site photos, and point cloud models to the smartphone GNSS rover’s dedicated cloud, you can overlay and check them on a map in a web browser or share them within the team. Data aggregated in the cloud is stored aligned with drawings and design models, so the latest site conditions can be understood anytime, anywhere. High-precision, geotagged photos taken on site can be used directly in as-built management documents and daily reports, and because point cloud data and drawings can be handled on the same platform, the previously separate processes of verifying surveying results and preparing drawings and reports are now seamlessly connected. Additionally, after syncing to the cloud, you can safely delete data from the smartphone while it remains securely stored, allowing you to handle large volumes of 3D data without worrying about device storage—a welcome advantage on site.

Achieve Smart Construction with Easy LRTK Deployment

Finally, we introduce our product LRTK, which makes it easy to start smart construction using such smartphone GNSS rovers. LRTK is an all-in-one GNSS rover product designed to be attached to a smartphone (iPhone). By attaching a compact device that integrates the antenna and battery to an iPhone, high-precision positioning becomes possible using the QZSS Michibiki CLAS (centimeter-level positioning augmentation service), and with the dedicated app you can capture photos with high-precision position data and acquire 3D point cloud data. Below are LRTK’s main features.

• Point cloud measurement: Anyone can easily acquire high-precision 3D point clouds by combining GNSS positioning and the smartphone LiDAR scanner. The acquired point cloud data can be used for design comparisons and quantity calculations immediately after measurement.

• AR utilization: Display drawings and 3D models overlaid on the site via the smartphone screen. This makes it easier to intuitively grasp site conditions, such as checking staking positions and visualizing buried utilities.

• Cloud integration: Sync survey data and photos to the cloud for centralized management. You can check the latest point clouds and photos from the office and streamline sharing and report preparation.

• Completed with just a smartphone: Surveying tasks can be completed with just a pocket-sized GNSS terminal and a single smartphone. It is easy to introduce without specialized equipment or extensive experience, so smart construction can start even on small sites.

By leveraging LRTK, you can realize smart construction using these cutting-edge ICT technologies without special technicians or large-scale equipment. As a trump card for promoting digital transformation (DX) at construction sites, why not experience smart construction with LRTK?