Point Clouds for Volume Calculation Are Now Common Sense! Labor-Saving Techniques Chosen by Surveying Professionals

Table of Contents

• Introduction

• Benefit 1: Improved Reliability through High-Accuracy Volume Calculation

• Benefit 2: Streamlining Survey Work and Time Savings

• Benefit 3: New Technologies That Lead to Labor Saving and Cost Reduction

• Benefit 4: Improved Safety through Non-Contact Measurement

• Benefit 5: Consensus Building and Promoted Use through 3D Data Sharing

• Simple Surveying with LRTK

• FAQ

Introduction

In civil engineering and construction sites, volume calculations—such as the volume of embankments and excavations or the amount of piled materials—are performed routinely. Grasping these quantities is a critical task directly linked to construction costs and schedule management, but traditional methods have tended to be labor- and time-intensive. For example, methods that measure many heights and widths on site with tape measures or total stations and then compute cross-sectional areas on drawings to calculate volume by the average-end-area method require enormous effort as the target area grows. Also, because shapes are assumed from limited measurement points, errors easily occur and concerns about accuracy remain.

A rapidly spreading new approach that addresses these issues is 3D measurement using point cloud data. By scanning a site with laser scanners, drones, or even smartphone and tablet LiDAR, you can digitally record terrain and structures as countless points (point clouds). When that data is displayed in a dedicated point cloud viewer software, distances, areas, and volumes can be freely measured from the acquired 3D model.

If you introduce volume calculation using point cloud data into your workflow, you can instantly derive required quantities from the detailed data obtained by a single 3D measurement. Think of it as creating a digital copy of the entire site: you can objectively understand details that aren’t visible in plans or photos. Support from initiatives like the Ministry of Land, Infrastructure, Transport and Tourism’s *i-Construction* has accelerated adoption, and the era when “measuring volume with point clouds is standard” is nearly upon us. This article describes five main benefits of adopting point cloud–based volume calculation and explains how the latest technologies improve the accuracy and efficiency of surveying work.

Benefit 1: Improved Reliability through High-Accuracy Volume Calculation

One of the greatest advantages of point cloud measurement is that it enables significantly higher-accuracy volume calculation than traditional methods. 3D point cloud data records fine undulations and shapes of the ground and structures as countless points. Unlike estimating shape from a few manually measured points, point clouds capture the entire object without omission, so the measurement data used for volume calculation has no gaps. For example, when measuring the amount of embankment or soil, you can compute accurate volumes that reflect surface irregularities and slopes.

This increase in accuracy greatly improves the reliability of progress control and quantity reporting. Previously, measurement methods and results could vary by person and sometimes relied partly on assumptions; with point cloud measurement, the same data yields the same quantities regardless of who performs the work. Quantities based on objective digital records provide clear proof and make explanations to clients and stakeholders more persuasive. Furthermore, once point cloud data is obtained it can be analyzed offsite at any time. It is easy to cut arbitrary cross-sections and recalculate volumes later, so if any omission is discovered you don’t have to return to the site. Because you can add measurements on the data, errors due to missed measurements are also prevented.

Moreover, advances in point cloud technology have dramatically increased measurement accuracy itself. Results vary by equipment and method, but there are reports that even simple smartphone LiDAR scans, with some technique, can achieve errors of about 1 cm (0.4 in). In fact, there have been cases where tablet LiDAR measurements yielded results within 0.1% error compared to drone surveys. High-end laser scanners can of course achieve millimeter-level accuracy, and comparable levels are increasingly attainable with more accessible measurement methods. In other words, by leveraging these latest technologies you can achieve high-accuracy volume calculation, dramatically improving the accuracy and reliability of site surveying data.

Benefit 2: Streamlining Survey Work and Time Savings

A major benefit of adopting point clouds is the streamlining of surveying and quantity calculation tasks. Acquiring 3D point clouds covers wide areas in far less time than traditional manual work. For example, a tripod-mounted terrestrial laser scanner can measure the surrounding area in a matter of minutes, and a drone can digitize a large site from the air in a short flight. Recently, using smartphone or tablet LiDAR, a single operator can obtain surrounding point cloud data in a few minutes to a dozen minutes simply by walking the site. Areas that previously required survey staff hours and dozens of point measurements can be captured in one scan by machine.

In addition, volume calculations from acquired point cloud data are automated in software, greatly reducing the time spent on calculations. In the past, tedious work was necessary to compute cross-sectional areas and sum them in spreadsheets, but with a point cloud viewer you can specify the area of interest and get results with the press of a button. Because volumes can be determined on site, you don’t have to return to the office to recalculate.

There are real-world reports of dramatic time savings thanks to point cloud technology. On one construction site, a tablet LiDAR 3D measurement of an excavation area—which previously took more than half a day (about 5 hours) with drone photogrammetry—was completed in about 30 minutes total. By eliminating flight planning and photo processing and performing scanning and volume calculation on site, the task time was reduced by about 90%. Even if not so extreme, many report that surveying now finishes in “less than half the time before” or that “other tasks can be done while data processing used to be awaited.” Shorter surveying and quantity-calculation times increase productivity, create slack in the overall schedule, and enable earlier starts to subsequent work, contributing to shorter construction periods.

Benefit 3: New Technologies That Lead to Labor Saving and Cost Reduction

Efficiency gains from point cloud technology directly address issues like labor shortages and rising costs. Because wide-area surveying can be accomplished with fewer personnel, labor saving can reduce personnel and outsourcing costs. Tasks that once required a specialized survey team and a full day can now, with modern measurement equipment, be completed by a single operator in a short time. For sites suffering from chronic technician shortages, point cloud measurement is a powerful solution that allows accurate surveying with limited staff.

Automation of measurement and calculations also reduces human error. Mistakes in measuring or calculations that lead to rework or additional work due to quantity shortfalls can be avoided, cutting wasteful expenditures. Quantity calculations using point cloud data are less dependent on worker skill level and consistently produce results of the same quality, reducing variability. As a result, sites spend less time handling surveying and quantity-management issues, leading to overall cost reductions.

Also noteworthy is that the initial investment cost for modern point cloud technologies has fallen markedly compared to before. Once expensive laser scanner hardware and dedicated software are no longer the only options; drones and smartphones now offer more affordable alternatives. For example, combining a small, high-precision GNSS receiver that attaches to a smartphone with a dedicated app can provide high-precision point cloud measurement and volume calculation that formerly required equipment costing millions of yen. This makes the technology affordable even for smaller sites and makes one-device-per-person operation realistic. If every staff member can survey with their device, wasted time waiting for surveying is eliminated and overall site productivity improves.

Benefit 4: Improved Safety through Non-Contact Measurement

Another major advantage of point cloud technology is improved safety. Point cloud measurement is fundamentally non-contact, using laser irradiation or photography, so surveyors do not need to enter hazardous areas. For example, when measuring excavation on a steep slope, staff previously had to climb the slope and use tapes; with drones or long-range laser scanners the entire slope can be measured from a safe distance, reducing collapse risk. Similarly, on construction sites where heavy machinery is operating, remote scanning reduces the need to stop work or send people near equipment.

Point cloud technology thus provides the major benefit of avoiding dangerous areas for surveying. There are reported cases in mountain road work where 3D laser scanning measured slope as-built without workers approaching the valley edge, and river works where fast-flow areas were measured safely from land using laser scanning. The high-precision point cloud data obtained can also be used directly for site safety management. For example, creating detailed ground surface models from point clouds allows early detection of landslide signs through analysis, and regular point cloud scans for monitoring displacement or deformation of structures can prevent accidents due to deterioration. A point cloud viewer is not just a tool for measuring volume but has high value as a digital tool for safety measures.

Benefit 5: Consensus Building and Promoted Use through 3D Data Sharing

Detailed 3D data obtained from point cloud measurement is powerful for post-survey information sharing and stakeholder consensus building. Because point cloud data is intuitive three-dimensional information, it makes site conditions that are hard to convey with 2D drawings or numbers immediately understandable. For example, showing pre- and post-construction terrain changes with 3D point cloud models or overlaying planned alignment from design drawings onto as-built point clouds lets even non-experts visually grasp differences. In one case, when a site shared point cloud data and a viewer with the client, they highly appreciated that “the current conditions were easier to understand than on a plan.” Seeing in 3D makes explanations and discussions smoother and can shorten meeting times—truly proving that “seeing is believing.”

Furthermore, acquired point cloud data becomes a digital archive and long-term asset. Unlike paper drawings or photos, it does not deteriorate or take up space, so keeping high-precision site records helps future renovation planning and verification in case of disputes. If you scan the entire site once, additional measurements can be taken on the data later if you decide you need dimensions of a location you didn’t initially record. Point clouds allow repeated virtual surveying of areas you didn’t record at the time. This reusability of 3D data increases operational flexibility and reduces unnecessary re-surveys.

Sharing point cloud data is also becoming easier. Web-based point cloud viewers running in the cloud allow stakeholders who don’t have dedicated software to view and measure 3D data via a browser. Project members, clients, and subcontractors can review the same model together regardless of distance, enabling consistent information sharing. Thus, point cloud technology not only advances on-site measurement sophistication but also greatly contributes to smoother communication via digital data and overall DX (digital transformation) of operations.

Simple Surveying with LRTK

As described above, 3D measurement using point cloud data brings huge benefits to surveying work, and it is becoming difficult to justify not adopting it. However, some may hesitate due to concerns like “Can our staff really handle it?” or “We can’t afford expensive equipment.” One attractive approach to address these concerns is simple surveying using smartphone-based LRTK.

LRTK is a modern surveying system composed of a small high-precision GNSS receiver that attaches to a smartphone or tablet and a dedicated app. With this, anyone can easily achieve centimeter-level positioning accuracy (cm level accuracy (half-inch accuracy)) and simultaneously acquire point cloud data by scanning the surroundings with the smartphone’s built-in LiDAR sensor. In other words, this single device is an all-in-one tool that completes high-precision positioning, point cloud measurement, and volume calculation on the smartphone.

By using LRTK, 3D surveying that previously required specialized equipment becomes much more accessible. Just attach a pocket-sized device to your smartphone, walk the site to scan required areas, and you can check quantities such as embankment volumes on the spot. Acquired data can be uploaded to the cloud with one touch and viewed/shared from office PCs immediately. Complex processing is automated in the app, and the interface is mainly button-driven and intuitive, so even those uncomfortable with IT devices need not worry. Some even find it “easier than conventional total stations,” as you can perform high-precision surveying without worrying about complicated coordinate transformations or settings.

Don’t underestimate accuracy because it’s a smartphone. LRTK uses RTK GNSS positioning to assign accurate absolute coordinates to the acquired point cloud in real time. With geographic coordinates given with positional accuracy within a few centimeters, the generated 3D model aligns well with conventional survey maps and design data. This means you can achieve smartphone-based accuracy comparable to typical surveying equipment. Portable and easy-to-use LRTK is a solution that lets anyone enjoy the benefits of point cloud usage on site.

If you’re interested in volume calculation using point clouds but feel “it seems difficult” or “I’m worried about initial costs,” starting with simple surveying using LRTK is recommended. With a smartphone and a compact receiver, you can try 3D surveying easily from today. Once you use it on your site, you will likely appreciate its convenience and benefits. Use LRTK to bring point cloud technology closer and dramatically improve the accuracy and efficiency of your surveying operations.

FAQ

Q: What is a point cloud viewer? A: A point cloud viewer is software for displaying and manipulating acquired point cloud data (a collection of countless 3D coordinate points) on a computer. It visualizes the scattered points in 3D space as a volumetric image and generally includes analysis functions such as distance, area, and volume measurement. In short, a point cloud viewer is a tool that reads the massive point cloud data obtained by laser scanning or photogrammetry and enables “surveying” and “measuring” in digital space.

Q: Do I need special equipment to acquire point cloud data? A: There are several ways to acquire point cloud data, and you don’t necessarily need large-scale equipment to get started. High-precision terrestrial laser scanners or surveying drones produce high-quality point clouds, but in recent years smartphone and tablet LiDAR or cameras have made point cloud measurement more accessible. Solutions that turn smartphones into surveying instruments by combining small GNSS receivers with apps (such as the LRTK described above) have also emerged, so options range from familiar devices to professional equipment depending on budget and scale.

Q: How accurate is volume calculation using point clouds? A: Generally, volume calculation using point clouds can be expected to have higher accuracy than traditional manual methods. Point clouds obtained by laser scanners or photogrammetry tend to densely cover the object surface, so quantity calculation has smaller errors than conventional methods that assumed shape from limited points. Actual accuracy depends on equipment and measurement conditions, but under good conditions terrain can be captured with errors of a few centimeters or less, so volume calculation errors are accordingly small. For example, even simple smartphone measurements have achieved errors of about 1–2 cm (0.4–0.8 in) in some cases, demonstrating that acceptable accuracy can be obtained without expensive equipment. However, for measurements requiring millimeter precision (e.g., detecting minute displacements of structures), dedicated high-precision equipment should be used according to the application.

Q: I’m worried that introducing and operating new technology will be difficult. Can beginners use it? A: Modern point cloud measurement tools and software are designed to be user-friendly. Data processing is highly automated, and mainstream products produce results with button operations without requiring awareness of complex parameter settings. For smartphone-app-based point cloud measurement, simply moving the device according to on-screen instructions completes an automatic scan. Many users report that it was easier than expected for a first-time use, and in some cases it feels more straightforward than traditional surveying equipment. Products with tutorial videos and robust support are increasingly available, so you don’t need to learn everything from scratch to operate them intuitively. Even if you’re initially anxious, once you try it you’ll likely be surprised by how simple it is.

Q: I want to introduce new technology but worry about cost. Are there low-cost ways to start? A: While point cloud measurement may evoke images of expensive dedicated equipment, low-cost entry options have appeared in recent years. For example, using a smartphone’s LiDAR scanner or camera with an app, and adding a GNSS receiver as needed, enables 3D site measurement without assembling equipment costing millions of yen. Solutions like LRTK allow you to leverage a smartphone to keep initial investment down while achieving high-precision surveying. Cloud services can also eliminate the need to buy high-performance PCs or software. It’s a good approach to start with small sites or pilot implementations, verify cost-effectiveness, and expand gradually.