Solo Surveying Made Easy! Compact Surveying Instruments Become a Strong Ally for Site Supervisors

Solo Surveying Required in the Era of **Smart Construction**

In recent years, waves of ICT adoption have swept construction sites, and the use of digital technologies called smart construction has been rapidly advancing. Three-dimensional surveying by drones and machine guidance, among other measures, have been employed as part of *i-Construction*, promoted by the Ministry of Land, Infrastructure, Transport and Tourism, to improve on-site productivity. Against this backdrop, what has drawn particular attention is the reduction of personnel in surveying operations.

Traditionally, surveying required skilled surveyors and specialized equipment, and working in two-person teams was the norm.

However, in the construction industry, which is facing a severe labor shortage and an aging technical workforce, there is a demand for systems that can operate sites efficiently even with a small number of people. In fact, the number of workers in the construction industry has declined by about 30% since its peak in the late 1990s, and the aging of on-site personnel has become pronounced. *"I want to complete surveying on my own"* — that demand has been rising, and what has emerged as the trump card is compact surveying instruments.

What is a compact surveying instrument? Differences from conventional surveying

Compact surveying instruments are, as the name suggests, a general term for portable, small-sized surveying devices. These include palm-sized GNSS receivers and surveying devices that can be used in conjunction with smartphones — compact instruments that stand apart from traditional stationary equipment. For example, in recent years ultra-compact GNSS surveying terminals that can be attached to smartphones have appeared, making it possible to transform a smartphone into a high-precision surveying instrument. Also, electronic measuring devices such as laser distance meters can broadly be considered compact surveying instruments. Using these, distance measurements that were previously carried out by manpower with tape measures can be performed instantly and accurately by a single person.

In conventional surveying, it was common to set up large optical instruments such as a transit or a total station (TS) and have another person hold a staff (leveling rod) or a prism to take measurements — a two-person operation. The equipment was heavy and required effort to transport and set up, so surveying took time and labor.

In contrast, compact surveying instruments are designed to provide high-performance positioning and measurement while achieving a pocket-sized form factor and a lightweight body. They do not require heavy tripods or generators, and their convenience—being something you can quickly take out and use whenever you need—is a major difference. They are developed to be easy to handle even for those who are not specially trained surveyors, aiming to be surveying instruments as tools that anyone on site can use.

There have also been conventional methods, such as robotic total stations (robotic TS) that can be operated by a single person, but their high equipment costs and the need for skilled operation have prevented widespread adoption. Smartphone-connected compact surveying instruments, by contrast, are lower-cost and easier to use, and are characterized by dramatically lower barriers to field deployment.

How the Latest Technologies Enable "Easy Solo Surveying"

Using compact surveying instruments, tasks that previously required multiple people can be completed by a single person. The key is high-precision positioning technologies such as RTK-GNSS, which have rapidly moved toward practical use in recent years. The positioning accuracy of a typical smartphone's built-in GPS has an error of about 5–10 m. While this is fine for using map apps, it is completely unusable for tasks that require centimeter-level accuracy (half-inch accuracy), such as setting out building positions or surveying boundaries. This is where the RTK (Real-Time Kinematic) method comes in, which corrects satellite positioning errors and dramatically improves accuracy.

RTK works by having both a base station installed at a known point and a rover (the surveyor’s unit) simultaneously receive GNSS satellite signals, and by using the difference in their observational data in real time to cancel out errors. This reduces errors that in standalone positioning amounted to several meters (several ft) to about 1–2 cm (0.4–0.8 in). To perform RTK positioning in practice, you need to either set up your own base station on site or obtain correction data over the Internet by using the electronic reference point network operated by the Geospatial Information Authority of Japan or commercial correction information services. Furthermore, in Japan the Quasi-Zenith Satellite System Michibiki (QZSS) provides a centimeter-level positioning augmentation service (CLAS), and by using a CLAS-compatible receiver it is possible to perform real-time high-precision positioning via satellite even in mountainous areas that are outside mobile phone coverage. In the past, high-precision GNSS surveying equipment was typically stationary, weighed several kilograms, and required specialist knowledge to operate. However, today compact GNSS receivers that interface with smartphones via Bluetooth and the like have appeared, allowing anyone to utilize RTK positioning with just a smartphone.

By having smartphones serve as the user interface and communications unit and compact receivers handle high-sensitivity positioning, centimeter-precision surveying that until now could only be performed by skilled operators is becoming a simple one-person operation.

For example, a representative device among compact surveying instruments called LRTK is an ultra-compact RTK-GNSS receiver that attaches to iPhones and other smartphones. Simply attaching it to a smartphone via a dedicated case instantly transforms the smartphone into a high-precision positioning terminal. If a smartphone configured for network RTK (such as Ntrip) and the LRTK receive satellite correction information, you can acquire position coordinates one after another on site simply by walking and measuring each point. Slope as-built measurements that traditionally required an operator and an assistant in TS surveying can be completed with a single smartphone fitted with LRTK. Latitude, longitude, and height are automatically recorded just by tapping buttons on the smartphone screen at key points, so there is no need to take handwritten notes. In this way, compact surveying instruments that utilize the latest technology are making "easy surveying with a smartphone" a reality.

Furthermore, recent smartphones are equipped with LiDAR scanners (light detection and ranging sensors), and combined with compact surveying instruments, new applications are expanding. When scanning the surroundings with a smartphone camera to acquire point cloud data (3D data composed of a large number of points), the device can simultaneously determine your position with high accuracy, so even if you walk around a wide area the point cloud does not become distorted. The acquired coordinate data can be shared instantly via the cloud, and the surveying results on site can be checked in real time from an office PC. This kind of digital integration makes it easy to use and share measured data on the spot, which is another advantage unique to the latest compact surveying instruments.

Benefits of Compact Surveying Instruments

The introduction of compact surveying instruments brings immeasurable benefits to on-site operations. Let's outline the main advantages.

• Labor savings and reduced personnel: Because surveying tasks can be completed by a single person, the need to allocate personnel for surveying is greatly reduced. Even sites suffering from staff shortages can perform necessary surveys with a minimal number of people.

• Time savings and improved efficiency: Preparation of equipment and coordination among multiple people are no longer necessary, so measurements can be taken immediately when needed, shortening work time. Automatic data logging and cloud sharing allow the organization and reporting of measurement results to be carried out quickly.

• High-precision positioning: With RTK-capable surveying instruments, centimeter-level positioning accuracy (cm level accuracy, half-inch accuracy) can be achieved. Even easily usable devices can acquire high-quality data, yielding results robust enough for as-built management and quality inspections.

• Portability and responsiveness: Many devices are pocket-sized or lightweight, making measurements while moving around a site effortless. A single operator can go to and measure at high locations, confined spaces, or distant survey points, allowing the site to respond flexibly to any situation.

• Improved safety: Measuring with fewer people reduces the number of workers required in hazardous locations. Also, because surveys can be completed in a short time, safety risks are reduced for work on busy roads and similar environments.

• Low-cost adoption: They are priced lower than traditional surveying equipment, dramatically reducing startup and maintenance costs. Small and medium-sized enterprises and local governments that could not previously afford expensive equipment can now more easily adopt them as an accessible solution.

• Ease of data utilization: Positioning data and point cloud data can be obtained in digital format and imported directly into CAD drawings and 3D models. There is no need to re-enter numbers handwritten on paper, and because data can be shared instantly with stakeholders via the cloud, total efficiency including reporting and analysis can be achieved.

Useful to a Wide Range of People, from Site Supervisors to Surveying Beginners

Compact surveying instruments are a reliable tool not only for specialized surveying technicians but also for people in various roles. Not only site supervisors who carry out construction management on the front lines, but also ICT personnel who promote ICT adoption within their companies, land and house surveyors involved in determining land boundaries and registration, surveying beginners who are about to learn surveying, and municipal technical staff responsible for public works—all can benefit.

• Site agent: The site agent, who is the person responsible for the construction site, may be required to check as-built dimensions and perform layout marking as part of quality control. With a compact surveying device, they can measure the site themselves without waiting for a dedicated survey team and immediately check for discrepancies with the design drawings. This directly contributes to improved construction accuracy and prevention of rework, making it a valuable ally for site agents.

• ICT personnel: For ICT personnel in construction companies who are responsible for introducing digital technologies, compact surveying devices are also attractive tools. By linking data with drones and 3D scanners, they can promote construction DX (digital transformation). If a one-device-per-person setup is realized so that all site staff carry a smartphone surveying device, real-time progress and quality management using cloud-uploaded site data becomes possible. It also makes advanced uses easier, such as comparing as-built data with BIM/CIM 3D design models or overlaying and verifying site imagery using AR technology. For ICT personnel, this is an excellent opportunity to spread such cutting-edge technologies throughout the company and trigger a productivity revolution.

• Land and house surveyor: For land and house surveyors, who specialize in boundary determination and registration of land and building descriptions, labor saving and accuracy improvement are major issues. A compact surveying device compatible with network RTK enables quick control point surveys on site and acquisition of official coordinate values. Even in wide-area cadastral surveys of forests or farmland, a surveyor can efficiently visit measurement points alone, contributing to greater operational efficiency. The use of network RTK methods has been increasingly promoted in recent cadastral and registration surveys, and the emergence of compact surveying devices is expected to help streamline these official surveying tasks. The ability to work with light equipment and high mobility is appealing even at sites that traditionally required heavy equipment and multiple personnel.

• Surveying beginners: On civil engineering construction sites, new employees or those inexperienced in surveying may be assigned surveying assistance. Many compact surveying devices are operated via intuitive smartphone interfaces, so they are easy to use on site even with limited expertise. For example, a user-friendly UI on a smartphone app provides guidance, allowing even first-timers to record survey points and export them to drawings without confusion. Difficult calculations and adjustments are automatically handled by the device, easing beginners' concerns that "surveying seems difficult" and supporting practical on-site learning.

• Municipal technical staff: Compact surveying devices are also a reliable asset for municipal employees responsible for road and river maintenance, disaster response, and similar duties. In situations such as quickly measuring damage at disaster sites or conducting as-built inspections of construction locations with a small team, the ability for a single person to perform accurate surveys can dramatically speed up initial response. Some municipalities have already begun introducing compact GNSS survey instruments into disaster management departments and using them to rapidly grasp terrain in affected areas. In administrative settings that manage large jurisdictions with limited personnel, a portable surveying device can be a trump card for improving operational efficiency. Furthermore, if staff can perform necessary surveying themselves for routine inspections of roads, bridges, and construction supervision, it can reduce outsourcing costs and enable faster responses.

Summary: The Future Small Surveying Instruments Bring to the Field

With the advent of compact surveying instruments that can be easily operated by a single person, the world of surveying is undergoing a major transformation. Amid a decline in experienced personnel and reforms in working practices, adopting surveying tools that anyone can use on site has now become an essential trend. In fact, at sites that have introduced compact surveying instruments, there are reports that as-built measurements that used to take a whole day can be completed within the same day, demonstrating a clear labor-saving effect. These compact yet highly accurate devices support many people—from site supervisors to novices—and will improve both productivity and quality at construction sites. As technology advances further, new developments can be expected, such as intuitive positioning with augmented reality (AR) and unmanned surveying through collaboration with autonomous robots. Compact surveying instruments are likely to evolve into an everyday tool on future job sites.

Finally, one solution to watch for in realizing such simple surveying is LRTK (El-Arr-Tee-Kay). LRTK is a pocket-sized, all-purpose surveying device that attaches to a smartphone, and combined with a simple app that’s easy for beginners to use, it lets you easily start high-precision RTK surveying. By simply attaching the receiver, which weighs only 165 grams, to your smartphone, anyone can perform centimeter-level surveying anywhere. If you are interested in improving on-site productivity or reducing manpower, please consider simple surveying with LRTK. By leveraging LRTK, "Effortless solo surveying" can become a reality at your site as well. As a new companion you can carry in your pocket at all times, LRTK will significantly change the way on-site work is done. The [official site](https://www.lrtk.lefixea.com) publishes case studies and detailed technical information, so if you’re interested, please check it out. You will surely be surprised by its ease of use and high level of precision.