One-person Work with Confidence! Streamline Solar Construction Surveying with Smartphone RTK

Surveying Challenges at Solar Construction Sites

Surveying is an indispensable and critical process at solar power plant construction sites (so-called mega-solar sites). Accurate survey data are required for various purposes, including site development planning for vast areas, marking panel installation positions, as-built surveys after construction, and earthwork volume calculations. However, there were major challenges with conventional surveying methods.

First, surveying large areas requires enormous time and manpower. When attempting to survey mega-solar scale sites (several hectares or more) using total stations or conventional GNSS equipment, multiple-person teams often had to spend several days to complete the work. In mountainous or sloped terrain with poor lines of sight, it took even longer, placing a heavy burden on labor costs and project schedules.

Next, the issue of dependence on specialist technicians cannot be overlooked. Setting up total stations and converting measurement data into drawings requires advanced knowledge and experience, so there were many situations where reliance on seasoned surveyors was unavoidable. With labor shortages and an aging workforce across the construction industry, securing experienced surveyors is difficult, and surveying tasks tended to become person-dependent. Outsourcing to external surveying specialists also increases costs, making frequent survey updates difficult.

Furthermore, inefficiencies in handling and sharing survey data were also a problem. Traditionally, survey points measured on site were recorded by hand in field notebooks and later entered into a PC for drawing in the office. On large sites the number of points grows huge, and simply organizing data manually required tremendous effort and time. Because field-measured information could not be shared immediately with construction managers or designers, there was a time lag before survey results were fed back into design and construction, which could prolong overall schedules.

In this way, surveying at solar construction sites faced a double challenge of “workload due to scale” and “inefficiency of conventional methods.”

The Era of Solo Surveying Opened by Smartphone RTK

A promising solution to these issues is the approach of one-person surveying using smartphone RTK. Smartphone RTK refers to equipping a smartphone with a compact high-precision GNSS receiver and using RTK (real-time kinematic) technology to turn the phone into a survey instrument capable of centimeter-level accuracy (half-inch accuracy).

RTK positioning uses correction information distributed from known reference stations such as electronic reference points to correct positioning errors from multiple satellite signals like GPS and Michibiki (quasi-zenith satellites) in real time down to several centimeters (a few inches). While RTK surveying historically required stationary, expensive GNSS units and base stations, recent technological advances have made it possible with the convenient combination of a smartphone + pocket-sized receiver.

With smartphone RTK, surveying tasks that previously required two-person teams can be completed by a single person. Even non-expert staff can soon walk the site with a smartphone in hand and rapidly measure point after point. Carrying a pocket-sized, easy-to-use surveying device at all times and taking measurements whenever needed—this is what smartphone RTK makes possible.

Moreover, the efficiencies enabled by smartphone RTK extend beyond just the surveying work. Reduced surveying time leads to shorter project schedules and faster commissioning of solar power projects, contributing to earlier revenue. If a single person can quickly complete as-built surveys and position staking, it becomes easier to execute other construction tasks in parallel, improving overall productivity. Indeed, “one-person surveying” is becoming a transformative innovation that is changing the norms at solar construction sites.

Key Benefits of Smartphone RTK Surveying

By introducing smartphone RTK on site, the following benefits can be expected for surveying tasks in solar construction:

• Efficiency and labor reduction through one-person operation: With smartphone RTK, surveying that previously required multiple people can be performed by one person. Each worker can carry a surveying tool and measure points concurrently, dramatically speeding up surveying across large sites. For example, in cases where other crews previously had to wait for the surveying team to finish, each person could independently perform surveying tasks, reducing idle time and sharply improving overall project efficiency. The labor cost savings from reduced manpower are significant, making this an effective measure against labor shortages.

• Improved quality with centimeter-level accuracy (half-inch accuracy): RTK positioning achieves very high accuracy within a few centimeters (within a few inches), which can improve precision for tasks such as laying out solar panel racking positions and setting foundation piles. Compared to traditional tape-measure marking that relies on experience and judgment, errors can be minimized, raising construction accuracy and quality control. In practice, mounting a smartphone RTK receiver on a monopod (pole) can achieve horizontal positional errors of less than 1 cm (less than 0.4 in), in some cases matching the precision of professional surveying instruments.

• Reduced mistakes through digital measurement: Smartphone RTK measurements are digitally recorded on the smartphone, with automatic coordinate conversion and averaging processing. Handwritten field notes and human reading errors are eliminated, significantly reducing surveying mistakes caused by human error. For example, tapping a measurement button instantly records latitude, longitude, and elevation, and simultaneously converts and saves them into the project’s coordinate system such as plane rectangular coordinates. With no worries about digit misreads or transcription errors, one-person work can still ensure reliable survey quality.

• Easy to learn and accessible operation: Because smartphone RTK operates via a smartphone app, people unfamiliar with specialized equipment can handle it intuitively — it offers simple operability. By following on-screen prompts and pressing buttons, surveying is completed and results are displayed in real time. There is no need for complex settings or arcane operation procedures typical of traditional surveying instruments, so newcomers or staff with limited surveying experience can learn quickly. As a tool that “anyone who has used a smartphone can master quickly,” it helps resolve technician shortages and reduce person-dependence.

• Convenient data sharing through cloud integration: Positioning data and survey results obtained on site can be uploaded from the phone directly to the cloud for sharing. Point location information and notes are automatically plotted on web maps, eliminating the need to return to the office and manually input data into a PC. As long as there is an internet connection, the field and the office are instantly connected, allowing construction managers and designers to grasp the situation in real time. This speeds feedback from surveying to design and construction and facilitates smoother information sharing within the team. There is no longer a need to pass data via paper drawings or USB drives, and remote review and instruction become possible, making it effective for supervising sites from a distance.

• Visual support and improved safety through AR technology: AR (augmented reality) features combined with smartphone RTK also deliver great benefits on site. By overlaying design models or stake positions onto the actual scenery via the smartphone screen as AR displays, it becomes intuitive to see “what should be installed where.” For example, projecting a 3D model of a solar panel racking system onto the ground via AR allows stakeholders to view the expected completed appearance on-site, helping prevent construction mistakes and misunderstandings. Because smartphone RTK’s high-precision positioning means the virtual stakes displayed in AR align closely with actual positions, it is possible to reduce pile-driving location errors to nearly zero. These capabilities also contribute to improved site safety. Scanning and visualizing the positions of buried objects (such as conduit) in AR and sharing that with machine operators reduces the risk of accidentally damaging obstructions, and with a small crew everyone can proceed with a shared understanding—helping to prevent accidents caused by human error.

As described above, one-person surveying with smartphone RTK brings multiple benefits ranging from efficiency and labor reduction to accuracy assurance and safety. On solar power equipment construction sites, this new surveying method strongly supports DX (digital transformation), becoming the key to enabling rapid and precise construction even with limited personnel.

Smartphone RTK Surveying Realized with LRTK

Choosing a reliable tool is important to fully leverage the advantages of smartphone RTK. Enter the all-in-one surveying device "LRTK", developed by Refixia. LRTK is an ultra-compact RTK-GNSS receiver that can be attached to a smartphone, designed so anyone can easily perform centimeter-level positioning and various measurements.

Attaching LRTK to a smartphone transforms that device into a high-precision surveying instrument. Although it is a pocket-sized device weighing only a few hundred grams, it supports Michibiki (CLAS) and network RTK, enabling stable positioning even at sites where cellular signals are weak, such as in mountainous areas. Using the dedicated “LRTK app,” single-point positioning can be performed with one tap, and plane rectangular coordinates and elevation (geoid height) are automatically converted and displayed. You can add titles and notes to each survey point, and all acquired information can be uploaded to the LRTK cloud and shared with one click.

LRTK also includes AR functionality and point cloud measurement features, allowing you to use the smartphone camera and LiDAR to capture 3D point cloud data of the site and composite design models in AR to check positional consistency—enabling a wide range of tasks with a single device. For example, after surveying reference points, you can immediately 3D-scan the surrounding terrain with your smartphone, overlay the resulting point cloud with CAD design data to perform consistency checks, and more. On the cloud, features such as automatic alignment of point cloud data and design models and instant earthwork volume calculations are also provided, allowing surveying through design and construction management to be completed entirely on a smartphone.

For surveyors, construction managers, and site supervisors, smartphone RTK is already a reliable partner that makes one-person operations safe to entrust. By leveraging products like LRTK, surveying tasks in solar construction can be dramatically streamlined, realizing a new era of construction that balances labor reduction and high precision. If you feel current on-site surveying presents challenges, consider adopting a smartphone RTK solution. Harness advanced technology to make solar power plant construction sites smarter and safer.