Complete site surveying with a smartphone before exterior design! Accurate, fast field measurements with LRTK

Site surveying of the current conditions is an indispensable step when doing exterior (landscaping) design. However, traditional surveying has been time-consuming, labor-intensive, and required specialist knowledge. If accurate site surveying could be completed using only a smartphone, operational efficiency would dramatically improve. In this article, we introduce how to achieve accurate and rapid field measurements using the smartphone-linked high-precision positioning system LRTK. We explain in detail the points that allow exterior contractors to handle everything from surveying to proposals in a single streamlined workflow.

The importance of site surveying in exterior design

For residential exterior (landscaping) and garden works, it is critically important to survey the site accurately before construction. Mistakes in boundary lines can lead to disputes with neighboring properties; even slight positional errors can cause fences or walls to protrude into adjacent land or cause approaches to be misaligned with the plan. To prevent such problems and rework and to ensure the design quality is realized, meticulous surveying before starting construction is essential.

In exterior planning, understanding ground elevation and slopes is also important. For example, if ground heights are not measured accurately, drainage plans can be compromised and final finished elevations can become incorrect. In concrete slab slopes or garden creation, centimeter-level errors can greatly affect water flow and appearance, so precise elevation measurement and leveling work are required. In this way, site surveying is an extremely important process that forms the foundation for the quality and smooth progress of exterior construction.

Traditional surveying methods and the challenges for exterior contractors

The surveying methods traditionally used by exterior and landscaping contractors include total stations (TS), optical levels, and manual work using tape measures, staffs (measuring rods), and spirit levels. Skilled workers can achieve high accuracy with these methods, but the field has faced the following challenges.

• Labor and time burden: Using a TS typically requires at least two people (one to operate the instrument and one to hold the prism), and surveying can take a full day for large sites or many survey points. Using tape measures and layout marking requires repeatedly measuring and marking, which is very time-consuming; over long distances, tape sag and difficulty keeping a straight line cause cumulative subtle errors. Garden works with complex curved layouts require detailed measurements and calculations, which are a heavy burden using traditional methods.

• Surveying errors and human mistakes: Manual work is prone to human error when reading and recording numbers. For example, if a measurement of "503 cm" taken with a tape is mistakenly recorded as "508 cm," that is a 5 cm error. Slight misreadings on a spirit level can distort slopes. Measured points can also be erased by other work if stakes or chalk lines are removed, requiring re-measurement. Such human errors and rework can cause schedule delays and additional costs.

• Constraints from site conditions: In urban narrow sites or lots with many obstacles, it can be difficult to secure line-of-sight for a TS or to place the equipment—this has been a challenge for traditional methods. In courtyards surrounded by buildings where direct measurement from control points is impossible, temporary reference points must be set and indirect measurement taken, increasing procedures and the risk of mistakes. Thus, depending on site conditions, it can be difficult to ensure accuracy with traditional methods.

• Outsourcing costs: Even for small exterior jobs, hiring a licensed surveyor for accuracy can cost tens of thousands of yen. If handled in-house, the initial investment in expensive surveying equipment and personnel costs are large, and because surveying is not frequently required, companies are often reluctant to make that investment. As a result, adequate surveying is sometimes omitted and construction proceeds based on experience, which can lead to later rework.

How LRTK surveying with a smartphone works and how to use it

A new solution that addresses the above challenges is LRTK, which enables centimeter-level surveying easily with a smartphone. LRTK is a high-precision positioning system developed by our company that connects a compact receiver that fits in your pocket to a smartphone. Using real-time kinematic (RTK) methods, it immediately corrects the errors inherent in satellite positioning such as GPS, shrinking typical positioning errors of about 5–10 m down to just a few centimeters. For example, LRTK can acquire position coordinates with approximately horizontal ±1–2 cm and vertical ±3 cm accuracy, enabling measurements in the vertical direction that were previously difficult. Because this high-precision positioning can be handled in real time via a smartphone app, there is no need to repeatedly perform layout marking for each survey point. By connecting a dedicated LRTK receiver to a smartphone via Bluetooth and launching the app, one person can begin surveying immediately.

Basic usage of LRTK surveying:

• Prepare the equipment: Attach the palm-sized "LRTK Phone" receiver to your smartphone and launch the LRTK app. The receiver is a lightweight, battery-powered unit of about 165 g, so no complicated equipment setup is necessary. It connects wirelessly to the smartphone, eliminating cables and making it easy to carry on site.

• Positioning and point cloud scanning: While confirming coordinates on the app, simply bring the smartphone to the location you want to measure to obtain high-precision coordinates for that point. Additionally, by using the smartphone camera or LiDAR sensor to scan the surroundings, the system can automatically generate 3D point cloud data with absolute coordinates. Walking through the site while holding the smartphone records the entire property and prevents overlooked measurements.

• Data storage and sharing: Survey data and site photos can be uploaded to the cloud directly from the app. Office staff can check field measurement results in real time from a PC, and team data sharing is simple. As described later, this cloud integration enables the use of data for client proposals and construction management.

The LRTK app features an intuitive UI designed so that users without specialist knowledge can operate it without confusion. Complex settings and calculations are automated, allowing staff without surveying expertise to start using it immediately. It eliminates the complexities of traditional equipment, enabling anyone to achieve high-precision positioning with the ease of a smartphone app.

Creating 3D models with high-precision RTK positioning and point cloud scanning

The greatest features of LRTK are its exceptional positioning accuracy and the ability to create 3D models of the site. The RTK method reduces GPS positioning errors of several meters down to a few centimeters, providing accuracy for exterior site surveying that makes such errors negligible. Generally, RTK positioning accuracy is said to be about ±2–3 cm, giving confidence for positioning fine structures like fences and flower beds. Vertical measurements are similarly precise, so traditional separate water-leveling or leveling surveys can be handled in one workflow.

Moreover, using the smartphone camera or LiDAR point cloud scanning capability allows you to create a 3D model of the entire site as-is. With LRTK, merely walking the site while holding the smartphone captures high-density point cloud data, recording everything on the property—from building exteriors to fences and plantings, even window frames—in three dimensions. On the acquired point cloud, you can later measure height differences or distances between any two arbitrary points, so there is no need to worry about having "missed that spot." Scanning on site achieves zero measurement omissions, and any required dimensions can be checked later in the data. Because one person can scan every corner, even labor-short sites can efficiently create detailed as-built models.

Since the point cloud data carries geographic coordinates (latitude, longitude, elevation), it can be imported into CAD software and used as an as-measured site model, or cross-sections can be extracted to examine elevation differences—lots of applications are possible. Terrain and surrounding conditions that could previously only be imagined from planar site survey drawings can now be understood intuitively in 3D. LRTK point cloud scanning thus goes beyond simple surveying and creates digital assets that serve as the foundation for design.

Cloud data visualization, sharing, and AR display: improving proposal capabilities to clients

Survey data and point cloud models acquired with LRTK can be visualized and shared on the cloud immediately. Coordinates and photo locations measured on site are synchronized to the cloud-based "LRTK Web service" in real time, enabling colleagues or supervisors in the office to check data instantly. For example, in progress reports for exterior work, you can immediately share coordinate-backed updates such as "the gatepost foundation has been installed according to the plan," providing persuasive reporting to remote clients or supervisors. Using a cloud viewer, point clouds can be viewed in a browser without specialized software, and distance, area, and volume measurements can be completed online as needed. Because data can be used without high-performance PCs or dedicated software, the barrier to data sharing inside and outside the company is lowered.

Furthermore, LRTK enables enhanced proposal power through AR (augmented reality) display. If you preload design drawings or 3D models of the finished appearance into the LRTK app, you can project the completed image onto the site through the smartphone screen. For example, during an exterior work proposal, simply pointing the smartphone can overlay the planned garden, gate, or wall onto the actual site. This intuitive experience helps clients grasp the finished appearance that drawings alone may not convey, increasing the persuasiveness of proposals. Statements like "This is the image of a wall at this height" or "This is where the focal tree will be" can be shown as realistic visuals composited with the actual environment—an important differentiator. Being able to share the completed exterior design in advance reduces mismatches in client expectations and leads to higher satisfaction.

Applications for understanding current conditions: retaining walls, slopes, and existing structures won't be missed

LRTK point cloud scanning records every site detail comprehensively, making it extremely useful as a current-condition assessment tool in exterior planning. For example, if an old retaining wall exists on the property, its position, height, and slope can be accurately extracted from the point cloud model. Previously, assessment of the retaining wall’s tilt or structural soundness depended on craftsmen's visual judgment or partial measurements, but with 3D data these aspects can be analyzed objectively. On steep slopes, detailed scanning of surface undulations allows creation of cross-sections needed for earthworks and drainage planning. With centimeter-level data even on complex terrain, you can accurately determine where retaining structures are required and estimate cut-and-fill volumes.

Also, positions of existing site structures (garden stones, trees, sheds, lamp poles, etc.) can be accurately identified from point clouds. This enables planning layouts that avoid those items or design proposals that incorporate them. Traditional survey drawings often show only building outlines and boundaries and tend to miss small existing elements, but LRTK point cloud data reproduces the site’s current state completely, leaving nothing overlooked. This prevents design mistakes such as "discovering an existing drainage inlet later" or "not accounting for neighbor's tree overhang." Since scan data is stored in the cloud, if problems arise during construction, you can later review the as-built conditions for verification. Thus, LRTK dramatically improves the accuracy and comprehensiveness of site investigations and becomes a powerful tool supporting the reliability of exterior designs.

Differentiate your exterior proposals by using LRTK

By introducing smartphone surveying, exterior contractors can differentiate through proposal strength and service quality. First, using LRTK prevents delays in starting construction due to waiting for surveying and enables faster, more accurate plan presentation than competitors. For example, a site inspection that traditionally required dispatching a surveying crew over several days can be completed quickly by a single person with LRTK. You can acquire a same-day 3D model and accurate dimensions and reflect them in CAD drawings or renderings that day—this speed directly impacts client satisfaction and builds a reputation for prompt, reliable service.

Second, the persuasive power of proposals themselves improves. As noted above, presenting a completed-image overlay with AR or providing design explanations backed by detailed point cloud evidence adds value not available before. While competitors may rely on intuitive proposals, LRTK-using firms can present claims such as "We have surveyed the site to this extent" and "We measure to ±2 cm accuracy," which not only reassures clients but also showcases the company’s technical capability and modernity. In the construction industry undergoing DX (digital transformation), offering services that leverage the latest technology is a significant advantage. In fact, LRTK is gaining attention as a solution aligned with the Ministry of Land, Infrastructure, Transport and Tourism’s *i-Construction* initiative, and early adoption of this industry-standard high-precision positioning technology can enhance corporate image.

Moreover, the efficiency gains from LRTK offer cost benefits. By performing surveying in-house, companies can reduce labor and outsourcing costs and reallocate time saved from shorter schedules to other tasks. The high precision reduces the risk of rework and additional construction, so overall the equipment investment can be outweighed by cost savings. Thus, introducing LRTK is a key to simultaneously achieving "quality improvement" and "efficiency."

LRTK use cases in practice (residential exteriors, large-scale development, narrow urban lots, slopes, etc.)

LRTK smartphone surveying is powerful across a variety of site situations. Here are representative use cases.

• Residential exterior renovations: For exterior renovation of detached houses, accurately measuring existing buildings and gardens is crucial. LRTK can scan everything from the house exterior to the entire site so you can plan gate positions and approach shapes that match the current conditions. For example, knowing the building outer walls and window positions in the point cloud helps ensure new decks or patio roofs fit exactly. Preventing mistakes like "doors not opening" or "interference with windows" after completion is a major benefit. The acquired point cloud can be shared with the client via the cloud as a "model of the current home," deepening their understanding and reassurance of the renovation plan.

• Large-scale development earthworks and exterior works: In development sites, wide-area surveying and placement of many structures are required. With LRTK, tasks that previously required a surveying crew—establishing control points and positioning equipment—can be done one after another by a single person. For example, in a large subdivision, a single technician can measure streetlight poles, fences, and planting positions across a block, so construction teams are no longer held up waiting for surveying. With field accuracy of around ±3 cm, even wide sites can proceed confidently with the placement of street furniture and fixtures. Additionally, LRTK can quickly scan terrain with elevation changes, enabling use in earthwork quantity calculations and retaining-wall design. There are reports of large-scale topographic surveys that used to take days being completed in minutes, yielding huge schedule reductions.

• Narrow urban plots and irregularly shaped lots: In densely built urban areas or sites with intricate shapes, LRTK shows its true value. RTK positioning can determine locations from multiple satellites even without direct line-of-sight, so it works well in narrow sites where total stations are hard to use. It is especially effective for small-scale sites and narrow plots, and its use is expected to continue expanding. Irregular boundary lines can be accurately traced in point cloud data, enabling optimal layouts for odd-shaped lots. In sites facing narrow alleys, there is no need to bring in large equipment—measurements can be done with a smartphone, reducing nuisance to neighbors. In urban exterior design that makes the most of limited space, LRTK is a reliable ally.

• Sloped sites and properties with steps in elevation: Exterior works on sloped sites require slope measurements and designs that account for elevation differences. LRTK 3D measurement can capture elevation information across slope surfaces, enabling accurate decisions on where to cut and where to bring in fill. For example, even with a 2 m height difference on a site, the point cloud model allows detailed analysis of the shape of the step and its relationship to the surroundings. When installing retaining walls, required lengths and heights can be derived from as-measured data, reducing design errors. Also, when explaining the finished appearance to clients, showing the completed model including elevation differences improves understanding. In mountain or remote areas with unstable Internet, the LRTK receiver can use CLAS signals transmitted from Japan’s quasi-zenith satellite "Michibiki," maintaining high-precision positioning. Thus, LRTK enables stable surveying even on slopes and terraced sites, supporting complex exterior planning.

From site survey to design, proposal, and construction management — a single streamlined workflow

By introducing LRTK, exterior contractors can complete the entire workflow in-house from site survey to design, proposal, and construction management. Performing surveying internally removes the need to coordinate schedules with other departments or external vendors, allowing immediate transition to design after the site survey. Point cloud data can be directly imported into design tools, eliminating information transfer errors to designers. 3D models created during the design phase can be shared on the LRTK cloud and used by sales staff for client presentations, improving internal collaboration.

LRTK also proves powerful during construction. Site supervisors and workers using the LRTK app can place stakes or markings on the ground according to design positions. For complex-shaped paving or curved flower bed layouts, AR display of drawing data can project guide lines onto the ground, enabling construction that follows design intent. If construction progress measurements are uploaded to the cloud, construction managers at headquarters can check quantities and accuracy remotely. For example, coordinate-backed updates like "the foundation for XX has been installed in the designated position" can be shared immediately, streamlining reporting and approval processes with supervisors and clients. If problems are found, prompt instructions and corrections can be issued based on cloud data, minimizing rework.

Additionally, LRTK data is useful for aftercare and future expansions. Because all survey data is digitally stored in the cloud, information such as "where pipes were buried" or "the exact position of boundary blocks" can be retrieved at any time after project completion. When additional work is requested years later, existing structure locations can be identified instantly from stored data, avoiding the need to re-survey. By adopting LRTK, you can leverage digital data throughout the entire lifecycle — survey → design → proposal → construction → maintenance — dramatically improving continuity and reproducibility of operations.

Why LRTK is easy to use even for first-timers

When people hear "high-precision surveying," they may think only experienced surveyors can handle it. However, LRTK’s simplified surveying functions achieve an ease of use that allows even first-time users to adopt it quickly. The main reason is the aforementioned operational simplicity. The dedicated app automates expert operations and presents an intuitive interface, so onsite staff without surveying expertise can use it without hesitation. Complex coordinate system settings and positioning calculations are handled in the background; users simply follow on-screen guidance and move the smartphone to complete surveying. The design makes it accessible even to those new to surveying, feeling like an extension of familiar smartphone apps.

Another point is the low barrier to equipment introduction. The LRTK receiver is compact and lightweight enough to fit in a pocket, requiring no special installation work or licenses. There is no need for tripod setup or leveling work as with traditional instruments, and surveying can start within minutes of arriving on site. LRTK services are also available on subscription plans, offering an option to start operating without large upfront investments. This makes it easy for small and medium exterior contractors to adopt LRTK and to use it flexibly for the periods they need. Lower financial barriers encourage trial adoption.

Above all, LRTK was developed with the concept of "high-precision surveying anyone can do," and it has the potential to become a standard tool on future construction sites. There are increasing cases where less-experienced technicians successfully perform surveys with LRTK and achieve productivity improvements. LRTK, which makes advanced surveying techniques accessible on site, is a powerful tool to drive DX in exterior work. If you are experiencing challenges with your current surveying methods, we recommend you give smartphone-complete LRTK surveying a try. Even first-time users can quickly appreciate its effects and take their exterior work processes to the next level.