On-site Immediate Earth Volume Measurement! Dramatic Efficiency Increase with Single-Person Surveying — Labor Reduction and Cost Savings

Table of Contents

• Introduction

• Why on-site immediate earth volume measurement is required

• Traditional earth volume measurement methods and challenges

• Dramatic efficiency improvements and labor reduction brought by single-person surveying

• “Surveying anyone can do” enabled by the latest technologies

• What is simple surveying with LRTK

• Key points and precautions for field implementation

• Conclusion

• FAQ

Introduction

How much easier would site management be if you could accurately measure earthwork volumes such as embankment and excavation volumes on site immediately? At many construction sites, understanding earth volumes takes time and effort, and in reality you often have to wait for specialized surveying technicians or post-processing. If there is a time lag before survey results are available, construction decisions can be delayed and extra costs may occur. Especially in earth-moving projects and infrastructure works that handle large amounts of soil, it is required to grasp earth volumes on site immediately and respond quickly.

In recent years, technological innovation has progressed in surveying to solve these issues. By leveraging the latest ICT technologies, it is becoming possible for even a single person to easily measure earth volumes on site and obtain results on the spot. By combining smartphones or tablets with advanced positioning and sensing technologies, surveying work that used to require multiple people can be dramatically streamlined, enabling “simple surveying” that anyone can use.

This article organizes the importance of measuring earth volumes immediately on site and the challenges of conventional methods, explains the benefits of single-person surveying and the underlying latest technologies, and finally introduces a new surveying tool using smartphones: “simple surveying with LRTK,” exploring how it can lead to labor reduction and cost savings on site.

Why on-site immediate earth volume measurement is required

Large amounts of soil are moved daily in earthworks, and accurately grasping the quantity is extremely important for overall construction management. For example, if you can immediately know how much excavation has progressed and how much fill is still needed, you can manage construction progress and arrange heavy machinery and dump trucks efficiently. Also, in as-built management and quantity assessment, if objective earth volume data can be obtained immediately, it prevents mismatched understanding with the client and leads to smooth consensus building.

However, traditionally, even when you want to know earth volumes immediately, there is generally a time lag until surveying and data analysis are completed. Even if the site manager wants to make an immediate decision, there are times when they must “wait for survey results,” which can prevent progress to the next process and cause rework. Reporting earth volumes only as 2D drawings or figures is also hard to grasp intuitively, and explaining to stakeholders can take time. If you can measure and visualize earth volumes on site immediately, such time loss and communication issues can be greatly reduced.

Furthermore, the construction industry is facing a serious shortage of experienced surveying technicians. It is increasingly common for a single site manager to perform multiple roles, and calling in a specialized team for surveying each time is inefficient. If site personnel themselves can quickly measure earth volumes, it brings great benefits from the perspective of labor reduction.

Traditional earth volume measurement methods and challenges

Various measurement and calculation methods have long been used to understand earth volumes on site. However, each has challenges in terms of time, effort, and accuracy. The main methods and their characteristics are as follows.

• Surveying with a total station (TS): Can measure terrain elevations and positions with high accuracy, but acquiring many survey points over a wide area requires a great deal of time and effort. It usually requires two or more people and specialized operation skills. Equipment setup and post-processing are time-consuming, making it difficult to produce immediate results.

• Earth volume calculation by the average cross-section method: A calculation method long used in road construction. Cross sections are measured at regular intervals, and the volume is calculated from the cut/fill area at each section. It is useful as an approximate method, but surveying and calculation take time, and it cannot reflect fine surface irregularities, leading to potential errors.

• Drone photogrammetry: By creating a 3D model from aerial photographs, earth volumes can be calculated even for large sites. It is effective for grasping volumes over wide areas, but drone flights are constrained by weather and permits, and it inevitably takes time from shooting to analysis completion. It also requires skills to operate dedicated software and a high-performance PC, making it difficult to get immediate results on site. Initial setup costs are also relatively high.

• Visual estimation based on experience: Experienced equipment operators or supervisors estimate volumes subjectively, e.g., “equivalent to X dump trucks.” This allows quick decisions but has low accuracy due to subjectivity and risks large discrepancies with actual volumes. It can also cause disagreements with clients.

As described above, traditional earth volume measurement methods are all time-consuming and lack real-time capability. Accurate volume calculation requires specialized knowledge and experience, and it is not easy to grasp earth volumes immediately on site. While waiting for survey result analysis, construction may be interrupted, or reliance on rough estimates may lead to unnecessary excavation or filling and rework, resulting in inefficiency.

Dramatic efficiency improvements and labor reduction brought by single-person surveying

By using such latest technologies, surveying work that previously required multiple people can be completed by a single person. If one person can conduct surveying, there is no longer a need to wait for a partner or a surveying team. Measurements can be started at the moment you decide on site, and data can be obtained and checked on the spot, dramatically improving work efficiency. Eliminating the need to secure personnel or coordinate schedules for surveying will also smooth overall site planning.

The effect on labor reduction is also significant. On construction sites suffering from chronic labor shortages, tasks must be handled with limited personnel. With single-person surveying, site managers or operators themselves can perform measurements without having specialized surveying staff on site. As a result, personnel resources can be reduced and staff allocation optimized, leading to labor cost savings. Also, cases where multiple people enter hazardous areas to measure will decrease, bringing safety benefits.

Secondary benefits of efficiency gains and labor reduction include shorter construction periods and cost savings. If there is no waiting for surveying, overall construction progresses faster, and by preventing unnecessary equipment operation or rework you can reduce wasteful expenses. Single-person surveying, which can achieve both dramatic efficiency gains and cost reductions, will be an indispensable initiative for future construction sites.

“Surveying anyone can do” enabled by the latest technologies

What supports single-person surveying is the use of ICT technologies that have made remarkable advances in recent years. In particular, the sensors in familiar devices such as smartphones and tablets and advances in high-precision GNSS positioning technologies are key. The latest smartphones have built-in LiDAR sensors, which scan the surroundings with lasers to acquire point cloud data (a collection of numerous survey points). Using this point cloud data, software can automatically and instantly perform earth volume calculations that previously required manual cross-section creation. By comparing current terrain data with design surface data or differencing point clouds before and after excavation, fill and cut volumes can be calculated immediately. Because the entire terrain can be captured in detail without missing points, this method can provide more accurate earth volume understanding than cross-section methods.

The acquired survey data can also be intuitively visualized using AR (augmented reality) technology. By displaying measurement results overlaid on the site through the smartphone or tablet screen, survey data can be shared in a form that anyone can easily understand. For example, simply pointing a camera at the site can display terrain elevation differences as a color-coded heat map, or guidance like “excavate another ◯◯ cm” can appear in place. Shortages or excesses in earth volume that were difficult to grasp from numbers and drawings alone can be understood at a glance visually. Because anyone can accurately understand the situation with digital visual information rather than relying on the intuition and experience of experts, communication is smoothed.

However, typical smartphone positioning has coarse errors on the order of several meters, which is insufficient to accurately overlay information in AR. This is where high-precision positioning technology called RTK-GNSS comes in. RTK-GNSS drastically improves position accuracy by applying correction data from a base station to satellite positioning signals. By connecting a dedicated small receiver to a smartphone, centimeter-level (half-inch accuracy) positioning has become possible on smartphones. In Japan, the availability of “CLAS (centimeter-level augmentation service)” provided by the QZSS Michibiki has also been a tailwind, enabling high-precision positioning with palm-sized receivers.

The combination of high-precision GNSS + LiDAR + AR has made a new generation of surveying tools usable by anyone on site a reality. Without large tripods or surveying equipment, accurate 3D surveying can be performed simply by walking the site with a smartphone in hand. Simple operability that even non-specialist surveyors can handle, and the convenience of obtaining results in real time, make surveying that anyone can do possible. This aligns with the Ministry of Land, Infrastructure, Transport and Tourism’s initiatives such as i-Construction and represents a technological innovation that can trigger a productivity revolution on construction sites.

What is simple surveying with LRTK

One concrete solution that realizes the combination of high-precision RTK-GNSS and smartphones described above is LRTK. LRTK is an ultra-compact RTK-GNSS module developed by Reflexia, a venture company spun out of Tokyo Institute of Technology, and is attached to a smartphone (currently compatible with iPhone) via a dedicated case. It weighs approximately 125g and includes battery and antenna, and is designed to be compact with a thickness of only about 1.3 cm (0.5 in). Simply attaching it to a smartphone enables centimeter-level (half-inch accuracy) high-precision positioning, transforming the smartphone itself into a usable surveying instrument on site. Each person’s smartphone becomes a “universal surveying device,” allowing anyone to easily perform surveying, stakeout, volume calculations, and AR visualization.

With simple surveying using LRTK, site supervisors or operators themselves can perform surveying without being specialized survey technicians. For example, on a residential land development site, an operator can check excavation volumes instantly by holding a smartphone from the cab of the heavy machinery without getting off. You can scan terrain with the iPhone’s LiDAR scanner to record as-built conditions, or display design models in AR to mark construction areas on site—the uses are diverse. Work that previously relied on instinct and rough visual estimates can proceed backed by digital surveying with LRTK, helping prevent mistakes and ensure quality. When explaining to clients, showing a 3D model or volume calculation results on the smartphone screen makes agreement formation straightforward.

As a tool that truly realizes “on-site immediate earth volume”, simple surveying with LRTK greatly contributes to labor reduction and efficiency. By skillfully adopting the latest technologies, surveying and measurement tasks that used to be time-consuming can be dramatically simplified, and anyone on site can access data when needed. Introducing these new surveying methods can change the way site operations are run and enable more waste-free construction management than before.

Key points and precautions for field implementation

When introducing single-person or smartphone surveying technology to a site, there are several points to keep in mind. First, it is important to provide sufficient training on equipment and software operation in advance. Although the tools are intuitive, learning the basics first—such as tips for stable positioning and accurate scanning—will reduce confusion on site. In particular, RTK-GNSS can sometimes take time to converge on the initial positioning, so it is good practice to power on equipment with time to spare before starting work.

Also, GNSS surveying requires a clear sky view to receive satellite radio signals. In mountainous areas, near high-rise buildings, or inside tunnels, RTK accuracy may be degraded. In such cases, consider auxiliary methods such as tying to known control points or using drone or ground-based LiDAR. For typical earthworks sites, high-precision positioning is usually possible, but attention is needed in environments with poor radio conditions.

For LiDAR scanning, avoid attempting to scan excessively large areas at once; divide the area and scan sequentially to prevent missing data. Dense dust or rain can degrade laser measurement quality, so pay attention to weather conditions. It is also a good habit to periodically cross-check acquired point cloud data and measurement results against existing drawings or reference elevations to confirm reasonable values, which increases confidence in the equipment.

Finally, to ensure everyone on site understands and can use the new surveying tools, information sharing and rule making are important. If you predefine operational procedures such as “when and at what timing to measure” and “how to record and share results,” you can maximize the benefits of single-person surveying. Taking account of the unique precautions of new technologies, aim to establish smooth adoption on site.

Conclusion

The era when a single person can measure earth volumes on site immediately is certainly approaching. The realization of “on-site immediate earth volume”, once unthinkable under conventional wisdom, has become attainable through the use of the latest technologies. Dramatic efficiency gains and labor reduction through single-person surveying offer a solution to the serious labor shortages in the construction industry. Greatly improving surveying efficiency not only brings direct benefits such as shorter schedules and cost savings, but also positively affects workstyle reform on site and the development of younger engineers.

The important thing is to adopt these new technologies on site without fear. You may be bewildered by differences from traditional methods at first, but once you try them you will be surprised by their convenience and accuracy. If everyone on site can use high-precision surveying data, waste in construction will be reduced and smooth site management without troubles will be realized. Utilizing “proactive ICT” to improve productivity will be a competitive advantage in the coming era.

Single-person and smartphone surveying are expected to spread increasingly. A central technology in this trend is the simple surveying with LRTK introduced here. If you feel challenges in site surveying, please consider leveraging the latest solutions. It may be a small step, but accumulating them will eventually yield great results and dramatically improve site productivity and safety.

FAQ

Q. Is single-person surveying possible without specialized knowledge or qualifications? A. Yes. The latest single-person surveying tools are designed for intuitive operation and can be used without being a professional surveyor. After basic training, site supervisors or heavy equipment operators can perform high-precision surveying. However, to achieve better results, it is recommended to become familiar with equipment operation and precautions beforehand.

Q. How reliable is the accuracy of smartphone surveying? A. Smartphone surveying using RTK-GNSS can be expected to have planar position errors on the order of several centimeters and vertical accuracy of several centimeters. While it is slightly inferior to conventional TS surveying or high-precision laser scanners, it is sufficiently practical for volume management in earthworks. Measurement using point cloud data has fewer omissions and leaks, and overall earth volume estimation accuracy may even improve.

Q. Can surveying be done in bad weather or at night? A. GNSS positioning generally works in rain or cloudy conditions, but positioning accuracy may be degraded in thunderstorms or heavy downpours. LiDAR scanners function in dark conditions, but accuracy can be affected during heavy rain or in dusty environments. Nighttime surveying is possible if there is illumination, but for AR-based visual confirmation the surroundings need to be well lit.

Q. What is needed to start simple surveying with LRTK? A. To use LRTK, you need a compatible smartphone (e.g., an iPhone with LiDAR), the LRTK receiver, and an application to operate the device. In Japan, it is also good to prepare an environment that can receive RTK correction information such as Michibiki’s CLAS. Support for initial setup and operation is recommended, but once configured you can immediately apply it to daily surveying tasks.

Q. What are the advantages compared with drone surveying or conventional TS surveying? A. Drone surveying can cover wide areas but has many constraints such as weather and flight permissions and lacks immediacy. In contrast, single-person smartphone surveying can be performed anytime as needed, and results can be confirmed on the spot — this responsiveness is its greatest advantage. TS-based precision surveying offers higher accuracy but requires manpower and time. Smartphone surveying reduces preparation and post-processing work, and for small-scale measurements its total efficiency often surpasses conventional methods. By using each method according to the purpose, you can maximize site productivity.