Realizing Precise Solar Plant Surveying with a Smartphone: Boosting Design Efficiency with LRTK and PVsyst

Surveying is indispensable for solar plant design to accurately grasp site topography and the surrounding environment. However, conventional surveying has required specialized equipment and advanced skills, consuming significant time and cost. As a result, in early stages designers often have to simplify terrain data or rely on general map information. Attracting attention in this context is a new surveying method using a smartphone and LRTK. LRTK is a high-precision positioning device that can be used with a smartphone, enabling centimeter-level surveying without dedicated equipment. In this article, we explain in detail from the perspectives of background, challenges, technology, utilization methods, effects, and integration with AR and point cloud data how smartphone and LRTK–based precision surveying can improve design efficiency and accuracy in designs using the world-standard solar simulation software PVsyst.

Background: The Importance of On-Site Surveying in Solar Plant Design

With the accelerated adoption of renewable energy in recent years, many solar plant projects are underway across regions. Their success requires accurately understanding the topography and surrounding environment of each candidate site and making appropriate design decisions. Accurately capturing site-specific terrain and irradiation conditions is critical when determining solar plant layout and expected generation. Slope angles and orientations, and the positions and heights of nearby obstacles that can cast shade (trees, buildings, etc.), greatly affect panel layout planning and loss calculations due to shading. Simulation software like PVsyst can produce more realistic generation estimates by inputting such site-specific information. For example, recommended racking designs and row spacing differ between gentle slopes and steep terrain, and tall nearby structures can cause year-round shading losses. Designing without accurate survey data risks unexpected shading effects or incompatibility with site shapes after completion, potentially leading to redesigns or reduced generation. Therefore, it is necessary to obtain precise survey data from the early stages and reflect them in the design.

Challenges: Problems with Traditional Surveying Methods

Conventional surveying is often perceived as something to be entrusted to specialists and generally involves setting up large-scale equipment and teams on site. Expensive specialized instruments such as transits, total stations, and GNSS receivers are used, and even establishing control points requires skilled personnel and precise adjustments. Thus, even small-scale survey tasks typically require hiring external surveyors, creating high time and cost barriers. Moreover, converting obtained survey results into digital data and reflecting them in design is time-consuming, and real-time information sharing between the field and the office is not easy.

Because of these barriers, early-stage solar plant designs sometimes omit detailed on-site surveys and base layouts on topographic maps from national mapping agencies or simple site checks. In those cases, accurate information on terrain undulations and adjacent object heights cannot be obtained, increasing the risk of discrepancies between simulated and actual generation. If detailed surveying is conducted after design, it can result in revising panel layouts or additional civil works (e.g., more land grading than anticipated), affecting project schedules and costs. In short, traditional methods created a dilemma of "knowing it's necessary but not being easy to do," which was a significant challenge for field engineers.

High-Precision Surveying Enabled by Smartphone × LRTK

Small smartphone-compatible surveying devices like LRTK that have appeared recently are changing surveying norms. They are attracting attention among site construction managers and engineers as "surveying instruments that fit in your pocket," and there is a movement to have one per person to improve work efficiency. LRTK is an ultra-compact RTK-GNSS receiver that mounts on a smartphone, instantly giving the attached phone centimeter-level positioning capability. RTK (Real-Time Kinematic) is a technique to correct satellite positioning errors, and by using correction information from base stations or the Quasi-Zenith Satellite System (Michibiki)'s centimeter-level augmentation service (CLAS), GPS positioning errors that are usually several meters can be reduced to a few centimeters or less. LRTK supports multi-frequency GNSS signals and can continue high-precision positioning even in mountainous areas without internet access by directly receiving CLAS signals. Dedicated smartphone apps allow users to check satellite reception status and accuracy, so anyone can reliably achieve high-precision positioning.

The biggest advantages of surveying with smartphone + LRTK are its ease of use and responsiveness. Preparation is complete simply by attaching a pocket-sized device to a smartphone—no heavy tripods or complicated setups are needed. Tap a button on the phone screen at the point to be measured, and latitude, longitude, and elevation are recorded instantly. Even non-specialist personnel can collect sufficiently accurate data alone by roaming the site, making detailed early-stage surveys that were previously postponed far easier to perform.

Another notable point is the ability to leverage the smartphone’s high-function sensors. By combining the smartphone camera or LiDAR (Light Detection and Ranging) sensor (※LiDAR-compatible models) with LRTK’s high-precision position information, the site can be captured directly as 3D point cloud data. Scanning the surroundings while walking the survey site yields a detailed 3D model composed of countless measurement points in a short time. Since each point in the point cloud is tagged with accurate coordinates, later analyses such as measuring distances, areas, height differences, or calculating terrain volumes and earthwork quantities become straightforward. Point clouds and survey coordinates can be shared to the cloud instantly from the field, allowing design staff in the office to check and utilize them in real time. Thus, LRTK technology transforms a smartphone into an "all-purpose surveying instrument," dramatically lowering survey barriers and greatly expanding the types and applications of data obtained.

How to Use LRTK Survey Data in PVsyst Design: Smartphone Survey Procedure

High-precision survey data from a smartphone and LRTK can be directly applied to solar plant design workflows. Below are general steps from on-site surveying to utilization in PVsyst.

• Acquiring site boundaries and basic information: Record the site boundary lines and shapes using smartphone surveying. Measure positions at the four corners or characteristic points of the site to determine the accurate area and shape. This clarifies areas available for panel placement and provides an exact footprint for layout studies in PVsyst.

• Collecting terrain (elevation) data: Obtain elevation data within the site. For large sites, set measurement points at regular intervals to capture heights, or use the smartphone’s scanning functions to generate a point cloud of the entire ground surface. From the resulting thousands to millions of 3D points, create a digital terrain model (DTM) to accurately model slopes and elevation differences. In PVsyst, these terrain data can be used to optimize panel tilt and arrangement and to evaluate variations in incident radiation caused by the terrain.

• Measuring surrounding obstacles and shading factors: Measure the positions and heights of objects that may block sunlight around the site (e.g., tall trees or buildings to the south). Using the smartphone’s camera AR functions or point cloud scans to capture tree tops or building edges allows you to obtain 3D positions with height information. This enables constructing an all-around horizon profile and nearby-object placement model, which can be reflected in PVsyst’s "horizon definition" and "near shading" scenarios. Accurate input of shading factors is essential, particularly for evaluating generation losses in mornings/evenings and during winter.

• Modeling survey data and importing into PVsyst: Prepare the collected survey data for import into PVsyst. Terrain and obstacle models derived from point clouds can be polygonized or simplified in CAD software as needed and imported into PVsyst’s 3D scene. Alternatively, extract key measurement points (for example, locations where site slope changes) and incorporate them into PVsyst as cross-sections or height maps. Recent versions of PVsyst have made 3D model import easier, allowing simulations to run using layouts that closely reflect the surveyed terrain.

• Design and simulation: Use the detailed terrain and surrounding information obtained in PVsyst to perform panel layout and system design. For example, arrange panel rows in terraces to match the terrain or avoid specific areas to optimize for site topography. Since surrounding trees and structures are reproduced in the 3D scene, PVsyst can simulate shadow movement by season and time of day and quantify annual shading losses. By obtaining precise simulation results (predicted generation and loss breakdowns) based on on-site survey data, investment decisions and construction planning accuracy improve dramatically.

• On-site verification and feedback: Once the design approach is settled based on simulation, perform on-site verification again using the smartphone and LRTK. Confirm with the phone’s navigation or AR display whether the planned panel row positions are feasible on the ground and whether assumed clearances and walkways are secured. If necessary, easily acquire additional survey data on the spot and feed it back into the design. Such iteration helps eliminate discrepancies between the desk plan and field conditions early, enhancing design completeness.

Following these steps enables full utilization of precise data obtained by smartphone surveying in PVsyst design and simulation. Projects that incorporate on-site information from the early stages will likely have smaller gaps after completion and less divergence between predicted and actual generation.

Leveraging AR and Point Cloud Data: Next-Generation Design and Construction

Combining detailed point cloud data obtained by smartphone surveying with LRTK’s high-precision positioning is advancing the integration of design and field work to a new level. A prime example is the use of AR (Augmented Reality) technology. Traditional AR has struggled with alignment errors and maintaining accuracy in large outdoor projects. However, as smartphones can now maintain centimeter-level position awareness, it has become possible to precisely overlay digital design models on the real world. Displaying 3D models of designed solar panel rows or equipment in AR on site gives the impression that the actual objects are already installed. Because the models remain correctly positioned and oriented even as users walk around, on-site checks and stakeholder briefings become intuitive and accurate.

For instance, projecting the designed layout onto the ground via AR allows immediate visual checks of setbacks from site boundaries and inter-row spacing. You can also compare simulated shadow lengths and directions at specific times with on-site observations to decide tree removal extents. Using AR helps identify elements that might be overlooked on paper or screens by allowing assessment at real scale, streamlining decision-making during design.

Meanwhile, obtained point cloud data can be viewed as a precise digital twin of the site. Using it within design software enables detailed design reviews while in the office, understanding site terrain and obstacles without being physically present. Overlaying point clouds and design models helps determine the extent of earthworks or retaining wall heights, and optimize routing for pipelines and cables. During construction, comparing as-built point clouds with the expected model aids in evaluating work completion, and AR displays of subsurface buried objects can reduce excavation risks.

Thus, survey data from smartphone + LRTK can be used beyond PVsyst simulations, and when combined with AR and point cloud technologies they support the entire lifecycle from design through construction and maintenance. In renewable energy projects, the boundary between digital and physical is increasingly blurred, promising more efficient and reliable project execution.

Conclusion: The Future of Solar Design Opened by Smartphone-Completed Surveying

Surveying methods using smartphones and LRTK are bringing innovation to solar plant design processes. Easy access to detailed site terrain and environmental data from the early stages dramatically improves the accuracy of simulations performed with PVsyst, minimizing redesigns and the risk of generation losses. The ability to complete surveying tasks that once required specialists with just a smartphone symbolizes a digital transformation (DX) in the renewable energy sector.

Designs supported by high-precision survey data make post-completion performance more reliable and lend credibility to investment assessments and stakeholder communications. Through visualization with AR and information sharing via the cloud, all project stakeholders can share the same site image, enabling smooth communication from planning through construction and operation.

Now that devices like LRTK have made smartphone-complete simple surveying a reality, if you face challenges in improving design efficiency or accuracy in solar projects, consider evaluating this smartphone surveying approach. The technology in the palm of your hand is likely to bring new possibilities to your project. The fusion of smartphone surveying and PVsyst simulation is poised to become the new standard in solar plant design, and scenes of measuring and designing with a smartphone in hand may soon become commonplace.