Table of Contents

• Why tools that can calculate earthwork volumes on-site are needed

• Traditional methods of volume calculation and their challenges

• What a smartphone-integrated earthwork volume calculation tool is

• How fast, high-precision surveys that anyone can perform work

• Benefits of sharing field data via cloud integration

• Effects smartphone surveying tools bring to the field

• Simple surveying with LRTK

• FAQ

Why tools that can calculate earthwork volumes on-site are needed

In civil engineering and land development sites, accurately understanding the volume of excavated or filled soil is extremely important. For quality control and reporting to clients, it is necessary to always know how much soil has been moved or how much more fill or cut is required. However, conventionally it has not been easy to perform immediate volume calculations on site. It was common to call surveying specialists to take careful measurements and then return to the office for analysis and calculation, which took time to produce results. As a result, even if the person in charge on site wanted to know the exact volume immediately, they often could not get an answer right away and had to rely on experience and intuition to make decisions.

Recently, the construction industry faces labor shortages and needs to respond to work-style reforms, so efficient construction management methods are strongly demanded. In addition, with the Ministry of Land, Infrastructure, Transport and Tourism promoting i-Construction, on-site digitalization (field DX) is rapidly progressing. Against this backdrop, expectations are growing for tools that can measure earthwork volumes in real time on site. If there is a tool that can calculate earthwork volumes on site, site staff alone can check as-built conditions even when surveying specialists are absent, greatly improving construction progress management efficiency. Being able to grasp volumes immediately when needed helps prevent rework and enables rapid decision-making, contributing to overall productivity improvement.

Traditional methods of volume calculation and their challenges

Until now, the following traditional methods have mainly been used to calculate earthwork volumes at construction sites. Each has its strengths, but they also have challenges when it comes to obtaining volumes immediately on site.

• TS (total station) surveying: This method sets up an electro-optical distance meter, measures the elevations and positions of many points on site to create a terrain model, and calculates volume. Although accuracy is high, surveying many points over a large area takes time and requires specialized surveyors and assistants. Because measurement through calculation takes time and effort, it was difficult to obtain results on the spot.

• Calculation by the average cross-section method: A method long used in road works. Cross-sections of the terrain are measured at regular intervals, and the fill and cut volumes for each section are calculated from the cross-section drawings and summed. It is a traditional method of calculating on drawings, but it cannot fully reflect terrain changes between sections and is approximate. Surveying, drawing cross-sections, and calculations take time and are not suited to real-time understanding.

• Photogrammetry using drones: A method increasingly common in recent years where unmanned aerial vehicles photograph the site from above, and photogrammetry software creates 3D models or contour lines to calculate volumes. It is effective for efficiently surveying large areas, but it is affected by weather, requires flight permission application procedures, and data processing needs specialized knowledge. It is difficult to complete shooting and analysis immediately, so results take some time to obtain.

• Visual estimation based on experience: Sometimes excavator operators or site supervisors roughly estimate volumes as “about X dump truck loads.” However, human judgment based on intuition can have large errors, risking discrepancies with clients and problems in progress assessments.

As described above, traditional volume calculation methods had issues such as requiring time and effort, needing specialized skills, and lacking real-time capability. Even if you want to know the exact volume immediately, the time lag from surveying to analysis makes it difficult to answer on site. Also, explaining volumes using numbers alone is not intuitive, and conveying the situation to clients or other departments with paper drawings or tables was challenging.

What a smartphone-integrated earthwork volume calculation tool is

To solve these problems, smartphone-integrated earthwork volume calculation tools have emerged. This is a new measurement system that combines a small positioning device attached to a smartphone, a dedicated app, and cloud services. Simply attach a device that fits in a smartphone pocket, and an ordinary smartphone is transformed into a high-precision surveying instrument.

Representative components of a smartphone-integrated tool are as follows.

• High-precision GNSS receiver: A GPS receiver that attaches externally to a smartphone. It supports RTK (Real Time Kinematic) GNSS, and by applying corrections to satellite positioning it improves positioning accuracy to on the order of a few centimeters (a few in). While conventional built-in smartphone GPS has errors of several meters (several ft), using this GNSS receiver achieves surveying-instrument-level accuracy.

• Smartphone built-in sensors (LiDAR, camera): Modern smartphones are equipped with LiDAR distance scanners and high-performance cameras that can scan surrounding terrain and structures to obtain 3D point cloud data. This enables detailed terrain undulations to be digitized and recorded.

• Dedicated surveying app: An application that runs on the smartphone. It acquires high-precision position information from the positioning device while real-time processing the point clouds and photo data obtained by the phone’s sensors. It also includes analysis functions such as volume calculation, allowing earthwork volumes to be calculated directly on site. The user interface is intuitive, designed so that anyone can measure simply by moving the smartphone following on-screen prompts.

• Cloud integration service: A service that stores and shares data acquired by the surveying app via the internet to the cloud. By uploading 3D models and numerical data from surveying to the cloud, office PCs and other team members can instantly share information. Point cloud visualization and volume checks can be done in a browser without special software, smoothing reporting and consultations.

With such a smartphone-integrated tool, high-precision surveying that once required large equipment and specialized knowledge becomes readily accessible. There is no need to carry heavy tripods or surveying instruments around the site; a smartphone and a small device can cover a wide site. It truly is an innovative solution that enables “anyone to easily calculate earthwork volumes.”

How fast, high-precision surveys that anyone can perform work

The reason measurements using smartphone-integrated tools are fast and high-precision is in their technical mechanisms. Here we explain the points that achieve high precision while remaining simple enough for anyone to handle on site.

First, RTK-capable GNSS is the key to high precision. The small GNSS receiver connected to the smartphone uses correction information from a base station (or augmentation signals from satellites) to enable continuous centimeter-class positioning. Because positioning accuracy is high, the obtained point cloud data and each measured point are assigned absolute coordinates, making on-site measurements directly comparable to design drawings or reference planes. Conventionally, after laser scanning a separate coordinate alignment process was required, but with smartphone-integrated tools, coordinate determination is completed simultaneously with measurement.

Next, the smartphone’s LiDAR sensor and camera contribute to speed through 3D scanning. Simply walking around a pile of soil or an excavation with a smartphone in hand, the LiDAR acquires hundreds of thousands of points per second and instantly generates a point cloud. Combining this with high-precision position information allows dimensions and volumes to be calculated on site, which is a major feature. Normally, processing point cloud data from 3D scans required significant time on a PC, but smartphone-integrated tools perform automatic processing within the app, so results are obtained simultaneously with measurement.

Furthermore, AR (augmented reality) technology is also utilized. Because virtual measurement results can be overlaid on the live camera view on the phone screen, results are intuitive to understand. For example, based on the measured volume data, displaying information such as “how many more cm to excavate to meet the design surface” as colored heat maps or numbers overlaid on the site image makes excesses and deficiencies instantly clear. Even inexperienced workers can visually understand the situation and make appropriate decisions on the spot.

An app UI designed to be “usable by anyone” is also an important point. By selecting a surveying mode and following on-screen instructions to move the phone, data is automatically captured and analyzed. Real-time display of positioning status and accuracy gives first-time users the reassurance to confirm whether the current measurement is proceeding correctly. By minimizing technical jargon and enabling completion with simple button operations, it truly becomes a surveying tool that “people who are not good with machines can use without hesitation.”

Benefits of sharing field data via cloud integration

Smartphone-integrated tools are not only fast for measurement; their value is further enhanced by cloud integration. Uploading data acquired on site to the cloud allows all stakeholders to share information regardless of location.

For example, if you upload measurement results to a company shared site via the cloud immediately after measuring earthwork on site, headquarters and personnel at other sites can instantly view that data. Since 3D point cloud models, photos of measured locations, and calculated volume numbers can be viewed on the cloud, stakeholders can grasp the situation with a sense of presence even if they are not on site. This enables prompt reporting to the site agent or supervisors and allows immediate instructions or additional decisions to be requested as needed.

Also, storing data in the cloud makes it easy to manage daily progress data in a time series. For example, if you scan and record the volume of the day’s excavations at the end of each day, you can view the progression of as-built conditions on the cloud. When verifying “when and how much soil was removed” or “how far along we are compared to design quantities,” having orderly data in the cloud makes confirmation smooth.

Of course, uploading to the cloud is optional. Sensitive data can be kept local, while information that needs to be shared can be safely distributed to stakeholders with one click. Eliminating the hassle of passing paper documents or USB drives, “measure on site and share immediately” becomes the norm. This is another major benefit supporting field DX.

Effects smartphone surveying tools bring to the field

Introducing smartphone-integrated surveying tools brings various effects to civil construction management sites. Below are the main effects summarized.

• Optimization of construction planning: Because volume data can be obtained instantly, construction plans and heavy equipment allocation can be revised on the spot. For example, if more excavation than planned is discovered, additional dump trucks can be arranged promptly, enabling proactive responses.

• Prevention of mistakes and rework: By visually confirming discrepancies between design drawings and the current state on site, mistakes such as over-excavation or over-filling can be prevented. Errors that used to be discovered only at as-built inspections can be corrected immediately through real-time measurement. This reduces rework, lowers costs, and shortens schedules.

• Smoother communication: Sharing digital 3D data and AR displays speeds up information exchange between the field, office, and clients. Seeing is believing; visual data leads to faster consensus than reports consisting only of text and numbers. Having objective data during progress assessments and on-site inspections also facilitates smoother discussions.

• Technical succession and human resource development: Because surveying can be done with simple smartphone-based operations, it becomes easier to entrust measurements to younger or new personnel. Parts that relied on veteran experience can be supplemented by the tool, reducing dependency on individuals. Even without seasoned staff, consistent-quality surveying becomes possible, helping address labor shortages.

• Improved safety: Dangerous slopes or deep excavations can be measured non-contact from a distance. Previously, surveying in locations with poor footing carried risks, but smartphone surveying eliminates the need to measure in unsafe postures. AR displays can also indicate hazardous areas, providing benefits for on-site safety management.

Thus, smartphone-integrated tools that can calculate earthwork volumes on site not only streamline measurement tasks but also have positive ripple effects across construction management. Real-time, accurate data increases the speed of on-site decision-making and improves overall productivity and safety. They can truly be called a trump card for field DX.

Simple surveying with LRTK

As one example of such innovative smartphone surveying tools, there is simple surveying using LRTK. LRTK is a system developed by Refexia Inc. consisting of a smartphone-integrated high-precision GNSS receiver and cloud services, used by attaching it to iPhone or Android smartphones. Using the dedicated LRTK app, you can perform 3D scans and positioning on site, allowing anyone to perform precise earthwork volume calculations in a short time.

With LRTK, there is no need to carry a heavy total station; surveying is completed with a palm-sized device. For example, if you want to measure the volume of a fill or backfill, simply scan around the target with a smartphone equipped with LRTK, and the cubic meters are calculated on the spot. Measurement results can be checked immediately on the smartphone screen and synchronized to the cloud and shared internally with one button. A major strength is that site personnel themselves can obtain and utilize necessary data without waiting for a specialist surveying team.

LRTK surveying is also designed to be easy for first-time users. The app is displayed in Japanese and easy to understand, with guides shown for each surveying mode, so those who are not good with machinery can use it with confidence. If you encounter difficulties on site, remote supervisors or technicians can view cloud data and provide advice, and support systems are fully in place.

If you are looking for a “tool that can calculate earthwork volumes on site,” simple surveying with LRTK is a compelling option. For sites aiming to improve efficiency and labor savings in earthworks, smartphone surveying using the latest technology is now indispensable. Consider trying it out on your site.

FAQ

Q: What exactly is a smartphone-integrated earthwork volume calculation tool?

A: It is a system where a small high-precision positioning device is attached to a smartphone and a dedicated app performs volume calculations. It dramatically improves smartphone GPS accuracy and automatically calculates volumes from 3D data of the site obtained by the camera and LiDAR. In short, the smartphone becomes a precise surveying instrument.

Q: Can people without surveying expertise use it?

A: Yes; it is designed to be usable by anyone. Measurements are completed simply by following the app’s on-screen prompts, so even those with little experience need not worry. The tool handles difficult settings and calculations automatically, and users only need to review the results. You can start using it intuitively without lengthy training.

Q: What level of measurement accuracy can be expected?

A: With GNSS RTK, under ideal conditions, horizontal position accuracy of about ±2-3 cm (±0.8-1.2 in) and vertical accuracy of a few centimeters (a few in) can be expected. In actual field conditions, you can grasp earthwork volumes with centimeter-level accuracy (cm level accuracy (half-inch accuracy)), making measurements comparable to conventional surveying instruments.

Q: What are the advantages compared to drone surveying?

A: Smartphone-integrated tools are more convenient and can be used immediately by anyone on site compared to drones. They do not require flight permissions or are not as constrained by weather, making them suitable for daily use even on small sites. The ability to obtain results in real time and reflect them immediately in construction is another advantage. However, drones can be more efficient for surveying very large areas, so choose according to the application.

Q: How are measurement data stored and shared?

A: Measured data is stored on the smartphone and can be uploaded to the cloud as needed. If saved to the cloud, point cloud data and measurement results can be viewed from an office PC via a browser, and shareable links can be sent to stakeholders. Data can also be exported as 3D models or CSV files, enabling use in internal reports or analysis with other software.