LRTK Phone Usage Guide [Complete Guide] Thorough Explanation from Beginner to Professional

Table of Contents

• What is LRTK Phone?

• Preparation and Setup

• Beginner: Basic Usage

• Professional: Advanced Techniques - 3D Point Cloud Scanning - Stake Driving Guidance (Setting Out) - Overlaying Design Data with AR - Photo Records and Coordinate Management - Cloud Integration and Data Sharing

• Simple Surveying with LRTK

• FAQ

What is LRTK Phone?

LRTK Phone is an innovative device that turns a smartphone into a high-precision surveying instrument. It is an ultra-compact RTK-GNSS receiver that attaches to your handheld iPhone or iPad and uses Real-Time Kinematic (RTK) correction technology to reduce positioning errors from the several meters common to regular GPS down to the centimeter level. Weighing approximately 125 g and small enough to fit in a pocket, it combines with a single smartphone to provide an all-in-one “universal surveying instrument” capable of positioning, 3D measurement, stake driving (setting out), and AR display. It attaches to a dedicated smartphone case with one touch, making it convenient to take out and use whenever needed. Positioning data, point clouds (3D scan data), photos, and more can be shared to the cloud instantly from the smartphone, allowing on-site measurement information to be shared with stakeholders immediately. It is designed so that it can be used without specialized equipment or advanced skills, making centimeter-level surveying easily accessible to everyone from beginners to professionals.

Traditionally, precise surveying and 3D measurement required expensive GNSS receivers, laser scanners, and multiple personnel. With LRTK Phone, however, the same tasks can be completed by a single person using only a smartphone and a compact device. By utilizing the Geospatial Information Authority of Japan’s reference station network and augmentation signals from Japan’s quasi-zenith satellite “Michibiki,” among others, accurate position information based on global coordinates can be obtained at any outdoor site. LRTK Phone greatly streamlines on-site surveying work and realizes the concept of “measure anytime, anywhere, by anyone.”

Preparation and Setup

First, confirm the preparation steps required to use LRTK Phone. The basic flow is organized so that even first-time users can set it up with confidence.

• Device attachment and preparation: Attach the LRTK Phone unit to the included smartphone attachment case. Fit the case securely to your smartphone (iPhone/iPad) and ensure the device is firmly fixed. Attach the supplied strap if necessary to prevent drops. Also check that the LRTK Phone unit is sufficiently charged before use (charging is done via a USB Type-C cable).

• Power on and Bluetooth connection: Press the power button on the LRTK Phone device to turn it on. Once startup is confirmed by LED indicators, enable Bluetooth on your smartphone. Then launch the dedicated “LRTK App” on your phone. Follow the app’s guides to pair (connect) the LRTK Phone device via Bluetooth. Once paired once, it will connect automatically from the next time.

• Login to the app and settings: On first use, you need to register (create an account) and log in to the LRTK app. After registration, check the various settings required for positioning. Grant access when the app requests permission for the smartphone’s location services (GPS), camera, and LiDAR sensor (on supported models).

• Connect to RTK correction services: High-precision positioning requires RTK correction information. In the LRTK app, connect to a network RTK service (for example, an Ntrip VRS service). Enter your Ntrip account and base station information so the app can receive correction data. Ensure your smartphone can connect to the internet (4G/5G or tethering, etc.). When connected to a correction service, real-time corrections are applied to positioning data received from multiple satellite systems such as GPS, GLONASS, and Michibiki (QZSS).

• Check positioning status: Confirm the current positioning mode and accuracy on the app screen. When RTK is functioning properly, a solution will typically reach a “FIX” state within several seconds to several tens of seconds. Once a FIX solution is obtained, the position displayed on the smartphone will improve dramatically and stabilize to an error of about 1-2 cm (0.4-0.8 in). If the indicators for positioning accuracy (satellite reception status and estimated error values, etc.) are green or show “fixed,” you are ready to proceed.

• Environment check before surveying: GNSS measurements achieve maximum accuracy in open-sky environments. Satellite signals can be blocked and accuracy reduced near tall buildings or dense trees. Upon arriving at the survey point, check the surroundings and, if possible, perform positioning in a location with clear visibility of the sky. Once preparation is complete, you can begin measurements using LRTK Phone.

If a known reference point is available on site, you can also position at that point at the start of the survey to check and correct errors (this is an advanced procedure, so beginners can proceed with measurements once the RTK FIX state is obtained).

Beginner: Basic Usage

Once you are ready, start with the basic single-point positioning (point survey) method. This is the procedure to measure the coordinates (latitude, longitude, and elevation) of a point on the ground and is the simplest and most frequently used function. Even beginners can perform high-precision positioning easily by following the steps below.

• Move the smartphone to the point to be measured: Carry the smartphone to the location you want to measure. If you want to know the coordinates of a specific ground point (for example, a boundary stake or the location for an equipment installation), bring the smartphone and LRTK device as close to directly above it as possible. If necessary, use a thin rod attachment or monopod that can be attached to LRTK Phone so that the device’s bottom can be placed directly on the target point for improved accuracy.

• One-touch position recording: Tap the “Position” or “Record” button on the LRTK app screen. That’s all it takes to record the current high-precision coordinates on the smartphone. The app collects positioning data in the background and automatically saves the latitude, longitude, and elevation. It also records metadata such as date/time, positioning mode (e.g., RTK fixed solution), and satellite count. Each measurement is automatically assigned a sequential number or provisional title, making it easy to manage and identify points later.

• Confirm positioning data: Once recording is complete, the point’s coordinates are displayed in the app. The app automatically converts and shows not only geodetic latitude and longitude but also values in Japan’s plane rectangular coordinate system and geoid height (height above mean sea level). If you want to name a measured point or add notes, edit them within the app—for example, “Reference Point A” or “Building Corner ①” for easy identification.

• Survey multiple points: To measure another point, move to it and press the button again. The LRTK app also offers a continuous measurement mode, where you simply move and press the button repeatedly to record points in succession. Each point is plotted on a list or map and numbered in measurement order, eliminating the need for on-site note-taking.

• Use results immediately on site: Measured coordinate data can be used immediately, not just saved. For example, the feature to measure distance between two points allows the app to automatically calculate horizontal distance and elevation difference by selecting two recorded points. This greatly simplifies tasks that used to require measuring tapes or levels. The app can also perform simple analyses such as area or angle calculations as needed.

• Cloud save and share (basic): Measurement data is saved on the smartphone and can be uploaded to the cloud with a single tap. After finishing positioning, press the app’s “Sync to Cloud” button. If you are in network range, all data will be saved to your personal cloud account and backed up safely. From an office PC, log in to the cloud via a web browser to view plotted survey points on a map or download data in CSV format. There’s no need to bring data back via email or USB, enabling immediate data sharing from the field.

That covers the basic single-point positioning workflow. In short: “Move to the point and press a button” to obtain high-precision coordinates easily. You’ll no longer need a paper field book—measurements are saved and usable as digital data the moment you take them, making tools like pens and tape measures feel unnecessary. Try this basic function first to experience LRTK Phone’s ease and accuracy.

Professional: Advanced Techniques

Once you are comfortable with the basic operations, try the advanced features to get the most out of LRTK Phone. The following advanced use cases will impress even professional surveyors and site managers. All of these can be achieved with just LRTK Phone and a smartphone and strongly support on-site digital transformation (DX).

3D Point Cloud Scanning

Using LRTK Phone with an iPhone/iPad’s LiDAR scanner or camera, you can scan the surroundings in 3D and obtain high-precision point cloud data. Standalone smartphone LiDAR scans traditionally lacked absolute coordinates (map coordinates), causing data distortion and difficulty in georeferencing. With LRTK, accurate latitude, longitude, and elevation are attached to each point in real time, so the scanned point cloud aligns directly with map coordinates. To use it, start the app’s “Scan Mode” and walk slowly around the target object or terrain. Move the smartphone as if recording a video, allowing the LiDAR laser to cover the area. For larger areas, walk in a grid pattern; if the app warns of “tracking lost,” retrace your steps slightly to fill in missed areas. After scanning for several minutes, press the complete button, and if possible, return to the start point for an overlapping pass (loop closure) to improve data accuracy.

The acquired point cloud can be displayed in 3D on the smartphone immediately. You can check for missing areas and perform simple edits, such as deleting unwanted points. Importantly, you can use the data immediately for volume calculations. For example, you can calculate the volume of stockpiled soil right away or take cross-sections to measure slopes—analyses that used to require importing point clouds to a PC and processing them in specialized software can be done on the spot with LRTK. Of course, for detailed analysis you can upload point clouds to the cloud and review them later at your desk. The ability to complete precise 3D surveying on a handheld smartphone—LRTK Phone’s point cloud scanning is becoming the new standard for on-site measurements.

Stake Driving Guidance (Setting Out)

Essential stake driving (setting out) tasks can be performed accurately by a single person using LRTK Phone. Specify the target coordinates in the app’s map or AR view, and use the navigation mode that displays the direction and distance to the target in real time on the smartphone screen. By following arrow markers and the distance meter, you move toward the target; when you approach, a virtual stake (marker) appears on the screen overlapping the ground at the exact target coordinate. Simply drive a stake or pin at that location to complete accurate setting out.

This guidance feature enables stake installation by a single person without specialized knowledge. Previously, experienced surveyors used transits or GNSS receivers and communicated with assistants to drive stakes. With LRTK Phone, you just move while watching the smartphone screen, eliminating communication errors. Points set once are saved in the app, making repositioning to the exact same spot later straightforward. This is useful for fixed-point monitoring or checking long-term changes. LRTK Phone’s setting out guidance significantly reduces the effort required for stake installation and reference point placement.

Overlaying Design Data with AR

The LRTK app includes advanced tools that leverage AR (augmented reality). This feature overlays prepared design drawings or 3D models onto the acquired point cloud data or current positioning coordinates. Because LRTK provides highly accurate absolute coordinates, simply pointing the smartphone at the site can produce AR displays where the virtual model and real-world environment align precisely.

For example, by AR-displaying a BIM/CIM model of a structure under construction on site, you can instantly check for deviations in the as-built shape or interference with other structures. Misalignments that are hard to grasp from drawings or photos become obvious when the virtual model is composited over the real image. For checking buried pipes or cables, display pre-construction scan point clouds or recorded data in AR to visualize underground structures through the smartphone even after backfilling. This enables data-driven visual checks in addition to experienced-based judgment, facilitating smoother consensus building and decision-making.

Photo Records and Coordinate Management

With LRTK Phone, on-site photos are more than simple records. When you take photos using the LRTK app, each photo file is automatically tagged with high-precision capture coordinates and camera orientation. This means the “when, where, and which direction” for each photo is accurately preserved as data. These photos can be linked to cloud maps and point clouds; for example, a photo capture icon can be placed on the point cloud model and previewed by clicking it.

This feature dramatically improves as-built management and construction record accuracy. You can perform fixed-point observations by photographing the same location weekly and comparing time-series photos, or compare photos to point cloud data to monitor progress. Detailed records of cracks in bridges or deformations in tunnels can be kept with precise location references and later cross-checked against point clouds. By organizing photos as part of the survey data on a map, report creation and information sharing become significantly more efficient.

Cloud Integration and Data Sharing

All data acquired with LRTK Phone—point coordinates, point cloud models, photos, voice memos, etc.—are integrated with the cloud in real time. As mentioned, data is automatically uploaded from the smartphone upon measurement completion, eliminating the need to copy files via USB after returning to the office. In the cloud, data can be viewed and analyzed through map and 3D viewers. There is no need to install dedicated software: you can rotate and zoom point clouds in a web browser, cut cross-sections, and calculate volume differences.

Data sharing is one click. From a cloud project, issue a “shareable URL” and send the link to clients or team members so that anyone can view the data without logging in (passwords and expiration settings can be applied if needed). Recipients can freely change viewpoints in the browser, measure dimensions, and check as-built conditions. If you need in-depth analysis in-house, you can also download coordinate lists in CSV or common point cloud formats. Real-time information sharing closes the gap between field sites, headquarters, and subcontractors, enabling timely and accurate communication.

Cloud integration also expands how data can be used. For example, upload design data to the LRTK cloud to automatically align it with on-site point clouds and numerically calculate differences between as-built and design. This allows immediate feedback from field measurements into construction management and quality inspection. LRTK Phone, combined with its cloud platform, becomes a powerful on-site DX solution for professional users.

Simple Surveying with LRTK

As shown above, LRTK Phone offers advanced surveying and measurement features while being designed for ease of use. In other words, the era of “simple surveying” with LRTK has arrived. Anyone with a smartphone can measure a site and immediately share data for decision-making. Surveying work, once a task for dedicated specialists, is becoming part of routine on-site operations thanks to LRTK Phone.

For example, a young site supervisor can perform quick as-built checks or quantity verifications by mastering basic LRTK Phone operations. Even without a veteran surveyor, the ability to measure and know immediately accelerates on-site workflows. If every person carries an LRTK Phone, measurements can be taken whenever needed, making plan changes and verification more responsive. This reduces downtime and staffing coordination, enabling both efficiency gains and quality improvements.

There are also significant cost benefits to simple surveying with LRTK. Initial investment is lower, subscription plans provide updates and support, and you can keep the system optimally maintained. There is no need to carry heavy tripods or dedicated instruments, making it easy to respond to any site with light equipment. By simplifying the specialist field of surveying, on-site DX will accelerate further.

From beginners to professionals, LRTK Phone provides value tailored to each use and skill level. It is simple and approachable for first-time users, and a reliable partner that dramatically increases efficiency and accuracy for experienced users. Adopt LRTK Phone on your sites and experience a convenient surveying workflow that overturns conventional expectations. With simple surveying using LRTK, you can help shape the future of on-site operations.

FAQ

Q. What smartphones are compatible with LRTK Phone? A. Currently, LRTK Phone supports Apple’s iPhone and iPad (iOS devices). Dedicated mounting cases are available for iPhone sizes, and a separate mounting holder is used for iPad. Android devices are not supported at this time.

Q. Can it perform positioning in mountainous areas with no cellular signal? A. Yes. LRTK Phone normally uses network-based RTK over a mobile connection for high-precision positioning, but by using the optional out-of-coverage kit (CLAS-compatible antenna model), you can position even outside mobile coverage. The device can directly receive centimeter-level augmentation service (CLAS) signals from Japan’s Michibiki satellites and use them for real-time corrections, enabling centimeter-level (half-inch accuracy) positioning even in mountainous areas or above underground infrastructure where mobile connections are unstable. Note that an unobstructed view of the sky (ability to receive satellite signals) is required.

Q. What level of positioning accuracy can be achieved? A. Under good environmental conditions with RTK maintaining a fixed solution (FIX), you can achieve approximately ±1-2 cm (±0.4-0.8 in) horizontally and ±2-3 cm (±0.8-1.2 in) vertically. This is a significant improvement over the several-meter errors typical of standalone smartphone GPS. Accuracy varies with satellite reception conditions; in urban areas with tall buildings or heavily wooded locations, accuracy may temporarily decline but will return to high precision once moved to a more open area or given more time. The LRTK app also includes a feature to average multiple positioning results to improve accuracy, which can yield millimeter-order stable positioning when used for critical reference point measurements.

Q. How long does the battery last? A. The LRTK Phone unit runs on an internal battery and provides about 6 hours of continuous use on a full charge (varies with usage and temperature). For long surveying sessions, you can recharge as needed with a mobile battery. Use the supplied USB Type-C cable to charge; a standard 5V 1A USB power adapter can be used. The device has a splash-resistant design (equivalent to IPX3), but avoid excessive exposure to rain and do not charge when wet. With proper care and charging management, it is reliable for field use.

Q. Can people without specialized knowledge really use it effectively? A. Yes. LRTK Phone is designed to be intuitive for beginners. Basic operations are guided in the smartphone app and only require pressing buttons, so you can obtain high-precision data without extensive surveying knowledge. Single-point positioning, as introduced in the “Beginner” section, is especially simple and easily used by anyone familiar with smartphone operation. Advanced features like point cloud scanning and AR are also guided by the app for reassurance. However, traditional surveying experience can be helpful when deciding how to use the obtained data (for example, comparing to drawings to judge as-built conformity). Start with basic functions and gradually try advanced features. LRTK Phone is designed to be learned by using it, and the more you use it, the more indispensable it becomes. Please use it proactively.