Streamline Field Surveys and Inspections: Easily Record Photo Orientation and Position with LRTK

Table of Contents

• The importance of recording photo orientation in field surveys

• Traditional methods for recording photo orientation and position, and their challenges

• What is LRTK?

• Easily record photo orientation and position with LRTK

• On-site benefits of photo position and orientation data

• Use cases for field surveys and inspections

• Simple surveying with LRTK

• FAQ

The importance of recording photo orientation in field surveys

In field surveys and infrastructure inspections, taking photos is indispensable for documenting conditions. Photos capture the site’s “now,” whether it’s construction progress, equipment deterioration, or disaster damage. However, if the photos lack information about the place (position) or the camera’s direction (orientation), it becomes difficult to accurately understand the situation when reviewing them later. For example, if a crack photo taken during a bridge inspection does not indicate “where and from which direction it was taken,” it can cause confusion when planning repairs. Similarly, if you don’t know from which direction a photo was taken during periodic inspections, you may not be able to correctly track changes over time.

If you record orientation and position information with a photo, you can precisely know “when, where, and in which direction” the photo was taken. This greatly improves the accuracy of on-site records and smooths later report preparation and analysis. Photos that are linked with spatial information do more than remain image files; they help build a three-dimensional understanding of on-site phenomena. For these reasons, recording photo orientation and position is strongly demanded to improve efficiency and reliability in field operations.

Traditional methods for recording photo orientation and position, and their challenges

Traditionally, recording a photo’s orientation and position in field surveys often relied on handwritten notes. Surveyors prepared paper maps or drawings in advance and, each time they took a photo, plotted the location on the map or noted latitude and longitude in a notebook. They also had to check the camera’s direction with a compass and note details such as “Photo A was taken facing northeast.” While shooting time is recorded by digital cameras, position and orientation were typically left to the personnel to record.

These methods have multiple issues. First, on-site note-taking is time-consuming and reduces the time available for surveying. Writing notes every time dozens of photos are taken is a heavy burden, especially in harsh environments like extreme heat or cold. Manual recording also carries the risk of human error—mistyped numbers, missed notes, or mismatches between photos and notes can lead to later confusion about what and where a photo actually depicts. In emergencies such as disaster response, delays in identifying photo locations can cause critical setbacks.

Moreover, organizing on-site notes is cumbersome. After returning from the field, personnel must match notes to photos, paste them into ledgers or reports, and write captions such as “Photo taken on MM/DD at HH:MM, Location: XX, Orientation: northeast.” This post-processing takes time and is prone to transcription errors. The more photos there are, the greater the burden, reducing efficiency.

Of course, GPS-enabled digital cameras and smartphones have made adding location information (geotags) more common. However, typical GPS has errors of several meters, which can be insufficient for precise location identification. Also, many cameras and smartphones do not record the orientation (shooting direction). Without orientation, you cannot tell which way a photo was taken, and you may have to infer direction on a drawing or rely on memory. Although some dedicated apps or expensive equipment can record orientation as well, they lack general applicability and are not yet widely adopted across entire operations.

As described above, traditional methods are hindered by time-consuming procedures, susceptibility to mistakes, and accuracy limits, which impede efficient and reliable management of field photos.

What is LRTK?

LRTK is a new technology that addresses these photo-management challenges. LRTK (LRTK) is a revolutionary system that enables centimeter-level (half-inch-level) high-precision positioning using a smartphone. In short, it turns a handheld smartphone into a high-precision surveying instrument. Specifically, it consists of a small RTK-GNSS receiver that attaches to an iPhone or iPad (weighing approximately 125g) and a dedicated app. Using this system can reduce typical GPS errors of several meters down to about 1-2 cm (0.4-0.8 in). By leveraging RTK (Real-Time Kinematic) correction technology and receiving augmentation signals from the Geospatial Information Authority of Japan’s reference station network and Japan’s Quasi-Zenith Satellite "Michibiki," it achieves accuracies unattainable with conventional GPS.

With LRTK, tasks that previously required experienced surveyors and expensive dedicated equipment can be performed with just a smartphone. The device itself fits in a pocket and can be attached to a special smartphone case with a single click. It pairs with the phone via Bluetooth, and positioning starts with a single tap in the dedicated app. No complicated operation is required; it is designed to be intuitive from positioning to recording. It truly embodies “anyone, anywhere, anytime” surveying and is expected to be used widely from construction and civil engineering sites to disaster response.

Beyond being a GNSS receiver, LRTK is an all-purpose surveying tool that supports field operations comprehensively. In addition to obtaining high-precision current position, it can perform 3D scanning (point cloud measurement) in combination with the smartphone camera and LiDAR, display design drawings or CAD data overlaid on real scenery using AR functions, and provide stakeout guidance for marking positions on site according to predetermined coordinates (setting-out). Tasks that once required separate specialized equipment and expertise can be handled all-in-one. Despite this rich feature set, LRTK remains simple to operate and accessible to beginners.

Easily record photo orientation and position with LRTK

One of LRTK’s greatest advantages is that it can automatically record position and orientation when taking photos. When you take a photo with a smartphone using the dedicated LRTK app, the photo file saves both the high-precision shooting position coordinates (latitude, longitude, altitude) and the camera’s facing direction. Positioning is done in real time, and because the smartphone’s location at the moment of shooting is determined with centimeter-level accuracy, the data preserves “from which point and in which direction the photo was taken” for each image. Field personnel only need to press the shutter; the additional information is automatically attached, ensuring the same accuracy and format regardless of who took the photo—an advantage in reproducibility.

Recorded position and orientation data can be used in various ways later. On LRTK’s cloud service, shooting locations are shown as icons on maps or aerial photographs; clicking an icon lets you view the photo. Shooting direction is also visualized on the map with arrows or sectors, so you can intuitively grasp spatial relationships like “this photo was taken from the west side of that building, facing east.” Moreover, you can link high-precision point cloud data (3D scans) obtained with LRTK to photos, placing photo-location markers on the point cloud model for management. Details not obvious from a single photo can be quantitatively analyzed by cross-referencing the point cloud model.

This automatic recording function revolutionizes on-site photo management. Handwritten note-taking is eliminated, and mismatches between photos and information cannot occur. Photos and their position data are integrated and uploaded to the cloud immediately after shooting, removing the need to reconcile photos and notes back at the office. Stakeholders can instantly share and view photos in the cloud, allowing supervisors or colleagues to grasp on-site conditions in real time. With photo orientation and position accurately recorded, field-acquired information becomes a trustworthy data asset that supports subsequent review and decision-making.

On-site benefits of photo position and orientation data

Attaching position and orientation data to each photo brings substantial benefits to field operation efficiency and information utilization. Here are the main points:

• Improved recording efficiency: Since photos are recorded automatically when taken, on-site note-taking is unnecessary. This allows surveyors and inspectors to focus on their tasks and make better use of limited field time.

• Prevention of human error: Automatic data attachment prevents manual recording mistakes and mismatches between photos and records. Uniform format and accuracy are maintained regardless of who takes the photos, reducing data variability.

• Easier time-series comparison: For fixed-point observations, it’s essential to shoot from the same location and direction each time. With position and orientation data, you can accurately reproduce shooting positions later, enabling precise comparisons of changes over time and progress checks.

• Enhanced spatial understanding: When photos are plotted on maps or 3D models, you gain a clearer view of spatial relationships that are hard to grasp from photos alone. It becomes obvious at a glance “from which position and what was photographed,” improving the persuasiveness of reports.

• Real-time sharing and remote support: Because photos and position data can be shared instantly via the cloud, headquarters staff or remote specialists can check photos and provide appropriate instructions or support without being on site. Communication between field and office becomes smoother, enabling quicker decisions.

• Data accumulation and DX promotion: Accumulating photos with orientation and position enriches the field database. This data can be used in analyses integrated with GIS or CAD systems and aid future planning and anomaly detection. It helps move away from paper ledgers and build a foundation for field DX (digital transformation).

By maximizing the informational value of photos, the quality and speed of field surveys and inspections can improve dramatically.

Use cases for field surveys and inspections

LRTK’s photo position and orientation recording can be applied across various field scenarios. Here are some specific examples illustrating its usefulness.

• Bridge and road infrastructure inspections: When photographing cracks in bridge girders or pavement damage, recording position and orientation with LRTK lets you link photos to exact locations on bridge or road drawings later. Information such as “photographed from the southwest side of Bridge No. X, looking up at the support” is preserved, so repair planning can proceed as if you were inspecting the object in person.

• Disaster damage surveys: In disaster response for landslides or floods, rapid information sharing is critical. Photos taken with LRTK can be uploaded on-site to the cloud and plotted on maps, allowing headquarters to grasp the situation remotely. Knowing “from which map point and in what direction a damage photo was taken” speeds up identifying hazardous areas and devising emergency measures.

• Construction progress management: Construction sites regularly document progress with photos, and comparing them correctly requires photographing from the same angles. With LRTK, shooting positions are recorded as data, making it easy to reproduce conditions such as “photographed the foundation facing north from the southeast corner of the site.” When arranging progress photos chronologically, consistent viewpoints provide persuasive comparison materials.

• Equipment inspection and maintenance: In factories or plants, photos with location data make it possible to accurately trace “which part of which equipment was photographed.” Even in large facilities with similar equipment arrays, mapping photos on facility maps or floor plans prevents oversights and misidentification, and eases handover for subsequent inspections.

As these examples show, using photo orientation and position information directly contributes to operational efficiency and sophistication. LRTK enables these initiatives smoothly, generating new value across various field tasks.

Simple surveying with LRTK

As described so far, LRTK offers advanced positioning and recording 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 the field, share data instantly, and leverage it for operations—surveying and recording tasks that were once left solely to specialists are becoming everyday activities with LRTK.

Simple surveying with LRTK also brings significant cost and mobility advantages. By lowering initial investment while providing high-precision functions as needed, it enables sites without dedicated survey personnel to obtain sufficient data. There is no need to carry heavy tripods or stationary equipment, and a single person can survey and record at multiple sites with light footwork. As the quantity and quality of field data improve, construction management and maintenance planning naturally become more accurate. Making specialized tasks simpler will further accelerate on-site DX.

In practice, the use of easy, high-precision surveying technologies is emphasized in digitalization initiatives in the construction industry promoted by the Ministry of Land, Infrastructure, Transport and Tourism, such as *i-Construction*. LRTK aligns with this trend, and municipalities and companies are beginning to adopt it. Consider introducing LRTK to your sites and experience a simple, smart surveying and recording workflow that overturns conventional wisdom. Simple surveying with LRTK will help shape the future of field operations.

FAQ

Q. Which smartphones are compatible with LRTK? A. Currently, LRTK supports Apple *iPhone* and *iPad* (iOS devices). Dedicated mounting cases are available for each model size to securely attach the receiver to the phone. (As of 2026, Android devices are not supported.)

Q. Can high-precision positioning be achieved even in areas without cellular coverage? A. Yes. Normally, network-type RTK correction information is received via the smartphone’s cellular connection, but in areas without coverage such as mountainous regions, an optional out-of-coverage kit can be used. This kit directly receives the centimeter-class augmentation service (CLAS) signals transmitted from Japan’s Quasi-Zenith Satellite Michibiki and uses them for real-time positioning correction. Therefore, as long as you have a clear view of the sky, centimeter-level (half-inch-level) positioning accuracy can be maintained even without cellular coverage.

Q. What level of positioning accuracy can be achieved? A. In good conditions when RTK maintains a “fixed solution (FIX),” horizontal position accuracy is about ±1-2 cm (±0.4-0.8 in), and vertical accuracy is about ±2-3 cm (±0.8-1.2 in). Compared to standalone positioning (typical smartphone GPS) with errors of several meters, this is orders-of-magnitude better. However, accuracy may temporarily degrade in urban areas with tall buildings or in heavily treed locations. In such environments, moving to an open area or waiting a short time usually restores high accuracy.

Q. How long does the battery last? A. The LRTK receiver’s built-in battery provides about 6 hours of continuous use on a full charge (varies with usage and temperature). For long surveys, you can connect a mobile battery to charge while using it. The device is splash-resistant (equivalent to IPX3), so minor rain is unlikely to cause failure, but avoid getting the device wet when possible and dry it thoroughly after use.

Q. Can it be used without specialized knowledge? A. Yes. LRTK is designed to be usable without specialist knowledge. Basic operations are performed with buttons in the dedicated app, and complex settings are automated. Even first-time users can intuitively perform high-precision positioning and photo recording by following the steps. That said, to fully leverage the data—such as assessing as-built conditions against drawings—civil engineering and surveying knowledge can be helpful. Start with the basic functions and gradually try advanced features. LRTK is designed to be learned through use, and you’ll appreciate its convenience more the more you use it. Please feel confident to apply it in your field operations.