On-site earthwork volume calculation, finished instantly! Easy, high-precision measurement and cloud integration with an all-in-one smartphone 3D surveying tool

Table of Contents

• Why earthwork volume calculation is required on-site

• Challenges of conventional earthwork measurement methods

• What is an all-in-one smartphone 3D surveying tool

• Accurately capturing site shape with point cloud measurement

• Automating volume calculation with cloud integration

• Benefits of introducing a smartphone surveying tool

• On-site use cases

• Simple surveying realized with LRTK

• FAQ

Why earthwork volume calculation is required on-site

On construction sites and civil engineering works, it is extremely important to accurately grasp “how much soil has been moved.” Knowing the amount of excavated soil or the volume of fill lets you estimate the number of dump trucks required and manage construction progress accurately. Conversely, misjudging soil volumes can lead to insufficient truck arrangements and project delays, or increased costs for disposing of excess soil, affecting the entire project. Accurate earthwork volume calculation is also essential for reporting to clients and for as-built management. However, calculating earthwork volume immediately on-site has not been easy, and traditionally it required time and effort. Site supervisors and workers want to know soil volumes as soon as needed, but there have been limited ways to achieve that.

Challenges of conventional earthwork measurement methods

Traditionally, several methods have been used to measure earthwork volumes on site. For example, using surveying instruments to measure terrain elevation differences, creating cross sections, and calculating volumes from them. However, this method typically requires multiple crews and takes a long time from surveying to calculation. Because results cannot be obtained immediately on site, decisions about the work often have to be postponed. Accurate reading and calculation can be difficult without experienced personnel, making the work prone to being person-dependent. Another approach has been estimating soil amounts visually or from the number of dump trucks, but this lacks precision and reliability. Furthermore, for irregularly shaped soil piles or highly undulating terrain, point-by-point measurements may fail to capture the shape accurately, resulting in large errors. In this way, conventional earthwork measurement has faced challenges in both efficiency and accuracy.

What is an all-in-one smartphone 3D surveying tool

To solve these problems, an all-in-one smartphone 3D surveying tool has recently emerged. This consists of an ultra-compact surveying device that attaches to a smartphone and a dedicated app, designed so anyone can easily perform high-precision surveying. It links with the smartphone’s camera and LiDAR sensor to capture the site as three-dimensional data. In addition, it includes a high-precision GNSS receiver (RTK-capable), achieving centimeter-level positioning accuracy (cm level accuracy (half-inch accuracy)) that is difficult with ordinary smartphone GPS. For example, in Japan, compatibility with the Quasi-Zenith Satellite System’s high-precision positioning service (CLAS) ensures stable accuracy even in mountainous areas with no mobile coverage. As a revolutionary tool that completes on-site measurement with only a smartphone and a small device—without heavy tripods or stationary surveying instruments—it is attracting attention. Such digital surveying technology aligns with construction DX initiatives promoted by the Ministry of Land, Infrastructure, Transport and Tourism, such as *i-Construction*, and is expected to become more widespread.

Accurately capturing site shape with point cloud measurement

One of the main features of all-in-one smartphone 3D surveying tools is that they can digitize the entire site shape via point cloud measurement. Point cloud measurement records countless points on object surfaces as a three-dimensional set of points (point cloud data). There is no need to measure and note heights one by one as in conventional surveying; simply walk around the site with your smartphone in hand to scan the surrounding terrain, fill, and excavation areas. A LiDAR-equipped smartphone sensor performs distance measurements on the order of hundreds of thousands of points per second to capture shapes, and the small surveying device’s GNSS gives absolute coordinates (latitude, longitude, elevation) to each point, so the acquired point cloud data includes accurate position information. Even for complex terrain or large soil piles, detailed shape data can be obtained in much less time than manual measurement. For example, even for a soil pile with irregular heights and slopes, visualizing it as point cloud data greatly improves volume calculation accuracy.

Automating volume calculation with cloud integration

Once point cloud data is acquired, the rest is simply calculating volume from that data. All-in-one smartphone 3D surveying tools can automate this volume-calculation process. Dedicated apps and cloud services instantly compute earthwork volumes from the acquired point cloud data. For example, for fill, the system analyzes the difference between the fill surface from the point cloud and the ground surface to calculate volume. Tasks that used to require taking survey data back to the office to produce drawings and apply volume formulas can now be completed on site. Large point cloud data are processed on high-performance cloud servers, so you can get results quickly without worrying about the smartphone’s processing load. Cloud integration also allows measurement results to be shared immediately over the internet. Because on-site measured volumes can be shared with headquarters or stakeholders right away, the need to return to the office to prepare reports is reduced. It is revolutionary in that anyone can obtain accurate volumes at the push of a button without specialized CAD software or complex manual calculations. Furthermore, the cloud platform can perform advanced analyses such as creating cross sections or measuring distances and areas from point cloud data. Because it can be used in a browser without installing dedicated software, it is easy for site and office staff to review the same data together.

Benefits of introducing a smartphone surveying tool

Introducing an all-in-one smartphone 3D surveying tool to the site offers many benefits. The main advantages are summarized below.

• Immediate results and efficiency: Conventional surveying-to-volume calculation sometimes took several days, but with this tool you can get results the same day. Waiting times are reduced and construction progress management becomes faster. Measured on-site data can be shared on the cloud immediately, allowing supervisors and other departments to check results instantly, accelerating decisions and instructions and preventing rework.

• Labor savings and countermeasure against workforce shortages: Because a single person can measure with only a smartphone and a small device, there is no need to allocate multiple people to the site. This is a major advantage in the construction industry, which faces severe labor shortages. Enabling site staff to measure themselves without relying on skilled surveyors also reduces the burden of human resource development.

• High precision and reliability: RTK-GNSS dramatically improves positioning accuracy, enabling positions to be measured with horizontal errors of about 1-2 cm (0.4-0.8 in) and vertical errors of about 3 cm (1.2 in) (ordinary smartphone GPS has errors on the order of 5-10 m (16.4-32.8 ft)). Volume calculations based on this high-precision data are highly reliable, eliminating visual estimation errors and manual calculation mistakes. This contributes to improved as-built verification accuracy and raises the level of quality control.

• Improved safety: The need to carry heavy tripods and surveying instruments into hazardous areas is reduced, lessening the burden. Small devices and a smartphone enable surveying from a safe distance, reducing risks associated with surveying work. For example, surveying on roads used to require traffic marshals and considerable time, but switching to quick smartphone surveying shortens workers’ exposure time on the road and improves safety.

• Data sharing and utilization: Measurement data can be shared internally and externally via the cloud immediately, allowing stakeholders to confirm results in real time. Even if a client cannot visit the site, you can share 3D data and figures online so they can understand the situation. Accumulated cloud-stored earthwork data also have high future value, such as serving as reference material for estimating similar projects or planning schedules.

• Cost reduction: Because surveying can be completed with few people and in a short time, labor costs and expenses for heavy machinery and equipment can be greatly reduced. Reduced downtime for surveying can shorten the construction schedule and lower indirect costs.

On-site use cases

How exactly can an all-in-one smartphone 3D surveying tool be useful on site? Here are some examples.

• Volume confirmation for fill and backfill: When fill is placed on site, you can measure and record the volume of newly placed soil on the spot. By immediately comparing with the design quantity, you can check whether additional soil is needed or whether there is a surplus. The same applies to backfill work, allowing on-site checks that the specified height has been achieved.

• Management of excavation volumes: In excavation work it is important to manage the amount of soil removed. If you scan the terrain before and after excavation with your smartphone, you can accurately calculate the volume removed. This enables accurate management of the number of dump trucks to be transported and arrangements for disposal sites. What was previously estimated from truck numbers and load capacities can be replaced with data-driven management, reducing waste and uncertainty.

• Measuring remaining soil and material stockpiles: Scan stockpiles of leftover soil, gravel, or crushed stone on site to determine inventory by calculating volume. Regular measurements make it easy to see how materials are diminishing and avoid missing the timing for the next order or shipment. Changes that are hard to see in photos or by eye can be quantified, improving inventory management accuracy.

• As-built management and reporting: If you acquire point cloud data of completed fill or formed terrain, you can use it to check whether construction matches the design (as-built management). By overlaying the design model and the current point cloud, you can color-code areas with insufficient height or excess fill and calculate the amount of corrective soil required. These results can be shared with supervisors or clients via the cloud and presented as 3D views or color-coded maps for intuitive understanding. Report preparation is smoother, and explanations during inspections or handover are easier.

As described, all-in-one smartphone 3D surveying tools can be applied to various on-site tasks including earthwork volume calculation, significantly contributing to improved work efficiency and quality control.

Simple surveying realized with LRTK

One example of a specific tool that realizes on-site earthwork calculation and 3D surveying benefits is LRTK. LRTK is a device that contains a compact RTK-GNSS receiver that can be attached to a smartphone with one touch and is used together with a dedicated app. This turns an ordinary smartphone into a high-precision surveying instrument. With a compact design that includes a battery and antenna, everything fits in one hand. Without transporting and setting up total stations weighing several kg, you can complete surveying with just a smartphone in hand. Using LRTK, anyone can start site surveying via point cloud measurement after a short training session and instantly calculate volumes of fills and excavations. Positioning accuracy reaches about 1-2 cm horizontally and about 3 cm vertically (0.4-0.8 in horizontal; 1.2 in vertical), achieving a level comparable to conventional specialized equipment. Acquired point cloud data can be uploaded to LRTK’s cloud service for analysis, and accurate volume results can be obtained within minutes after scanning on site. For example, even large volumes exceeding 200 cubic meters can be assessed by simply walking with a smartphone while using LRTK. Earthwork volume calculations that previously required specialist operators using heavy machinery and optical instruments are becoming “simple surveying” that anyone can perform thanks to LRTK. LRTK also provides site support features beyond surveying, such as stakeout guidance and AR display of underground utilities. As a solution that promotes site DX (digital transformation) and dramatically improves efficiency and accuracy, LRTK is attracting attention. Adoption is progressing rapidly at domestic construction sites, and it is expected to be a key driver of site DX. By leveraging such advanced tools, on-site earthwork volume calculation can be performed more quickly and reliably. Consider adopting new technologies to pursue smart site operations that balance productivity and safety.

FAQ

Q: Can it be used without special qualifications or surveying knowledge?

A: Yes, as long as you can perform basic smartphone operations, you can use it without specialized knowledge. The dedicated app interface is designed to be intuitive and easy to understand, allowing surveying with simple operations like tapping the point you want to measure or starting a scan. Complex settings and calculations are processed automatically in the background, enabling “simple surveying” that anyone can handle. In practice, many sites report that even workers using the tool for the first time could start using it after a short explanation.

Q: Are there limitations on the measurement range or distance?

A: It depends on the tool’s performance, but the effective range of typical smartphone LiDAR is on the order of several tens of meters. For example, with LRTK you can acquire point clouds up to about 60 m (196.9 ft) away. If you need to survey a very large site at once, you can divide the area into sections and later merge the point cloud data. Basically, any area within line of sight can be measured without problems.

Q: How accurate can the volume calculations be?

A: It is possible to calculate volumes with errors on the order of a few centimeters. The combination of high-precision RTK-GNSS positioning and point cloud measurement yields highly accurate geometric data for volume calculations. Therefore, the calculated volumes are extremely reliable compared to manual estimates. However, accuracy may vary slightly depending on the measurement environment (for example, near tall buildings or in dense tree cover).

Q: How long does measurement and volume calculation take?

A: It depends on the measurement area, but for a small site it can be completed in a few minutes. For example, scanning a fill area of several tens of meters square can be finished by walking around with a smartphone in about 5 minutes or less. Cloud processing of the acquired point cloud data also takes only a few minutes, allowing you to confirm accurate volume results on site. This represents a dramatic time reduction compared to conventional surveying, which used to take days for data organization and calculation.

Q: What advantages does it have over drone-based surveying?

A: Smartphone all-in-one tools excel in ease of use and immediacy compared to drone surveying. Drone surveys can capture wide areas from the air, but they are constrained by weather and flight permissions, and processing photos into point clouds takes time. In Japan, operating drones may also require qualifications or permits. In contrast, tools like a smartphone and LRTK allow you to start measuring by simply walking the site on arrival and obtain results via the cloud on the spot. They are also advantageous because they can be used in narrow areas and indoors.

Q: How are survey data stored and utilized?

A: Acquired data are stored in the cloud and can be viewed or downloaded whenever needed. Point cloud data and measurement results are uploaded to a dedicated cloud service where you can check 3D views and numerical reports in a browser. Data can be downloaded in CSV or drawing formats for use in other software. You can also issue sharing links so clients or partner companies can view data without logging in, enabling smooth information sharing among stakeholders. Accumulated cloud data can be used for internal report preparation and as reference material for future projects.

Q: Can measurements be taken in rain or at night?

A: Basically yes, but environmental precautions are necessary. LiDAR ranging works in the dark, so nighttime measurement is possible. However, ensure safe footing, and if using the smartphone camera for capture, supplemental lighting may be needed. Light rain generally does not interfere with operation, but water droplets on sensors or lenses may affect accuracy. Devices are splash-resistant, but avoid using them in heavy rain and perform measurements once weather conditions stabilize.

Q: Which smartphones are supported?

A: Most modern smartphones are supported. The dedicated device attaches to the phone and supports both iOS and Android platforms, allowing you to use your existing smartphone. LiDAR-equipped models are optimal for higher-density 3D scans, but non-LiDAR models can often generate point clouds via photogrammetry. Check the provider’s documentation for detailed compatibility information.