Manage Geotagged Photos on a Map All at Once! Inspection Work Greatly Streamlined

Table of contents

• Challenges of traditional inspection photo management

• What are geotagged photos?

• Benefits of managing geotagged photos on a map

• How to manage geotagged photos on a map all at once

• Simple surveying with LRTK

• FAQ

Introduction As social infrastructure and building facilities such as roads, bridges, tunnels, and buildings age, the importance of inspection work to keep them safe is increasing. In recent years, periodic inspections of bridges and tunnels have been mandated by law, and periodic reporting systems have been required for condominiums and office buildings, so demand for inspections is expected to continue to grow. However, performing inspections and maintenance efficiently with limited personnel has limits when relying on traditional analog-centered methods. Therefore, digital transformation (DX) of inspections using technologies such as drone photography, laser scanner measurements, inspection robots, AI image diagnostics, and AR (augmented reality) for on-site support is being explored in many places. Among these, a relatively easy-to-adopt and highly effective approach attracting attention is the digital management of inspection records using “geotagged photos.” In this article, we explain what geotagged photos are, review the challenges of traditional inspection photo management, and discuss their advantages and concrete use cases. At the end of the article, we also introduce how anyone can easily achieve high-precision geotagged records using the latest tool: simple surveying with LRTK.

Challenges of traditional inspection photo management

In conventional inspection work, it was common to paste photos taken at inspection points into paper ledgers or reports, or to organize them in folders by devising file names. However, there are the following issues with photo-based records and management.

• Difficult to determine where a photo was taken: Just by looking at a photo, it is often hard to tell later which part of a structure or equipment it shows. On site, photos are sometimes numbered and the shooting position is recorded on a separate sheet with notes like “photo number ○ = near 〇〇,” but this method is time-consuming and prone to human errors such as incorrect entries or mixing up photos.

• Information becomes person-dependent and hard to share: If the method of recording inspection results depends on each inspector’s personal practice or experience, a third party may not be able to correctly understand the location or situation from the photos. Management that relies on individual memory or intuition makes information sharing within the department or handover to successors difficult.

• Difficult to compare with past inspection history: When managed with paper ledgers or individual photo files, it is not easy to compare previous inspection results with current ones to track deterioration. Because data are dispersed, analyzing long-term trends requires extra effort, and valuable records may not be fully utilized.

• Time-consuming to organize records and create reports: Post-inspection photo organization and compiling reports rely heavily on manual work, which can be a major burden when dealing with large numbers of photos. Tasks such as pasting photos into a prescribed format one by one and writing positions and conditions in text take time and effort, and carry risks of omissions or misplacements. When managing many assets or operating with a small team, spending time on report creation can delay on-site responses.

To solve these issues, a new method is needed that digitally links photos with location information and manages them centrally. The key to this is the use of “geotagged photos.”

What are geotagged photos?

“Geotagged photos” are inspection records in which location coordinates (latitude, longitude, altitude, etc.) indicating where the photo was taken are attached to the photo file. Some digital cameras and smartphones can save latitude and longitude obtained from GPS or other sources into the photo’s Exif data at the time of shooting. Because geotagged photos have objective location information tagged to each photo, there is no need to manually link photos and maps as in the past, and the major feature is that you can tell at a glance “where the photo was taken” when reviewing photos.

Traditionally, inspectors manually matched spatial information and photos by marking inspection points on paper drawings or numbering photos and recording shooting locations on separate sheets. However, this approach inevitably relied on subjectivity and memory, making information inaccurate and hard to share. It is also possible to record latitude and longitude in photos using cameras with GPS, but the typical GPS accuracy can produce errors on the order of several meters (several ft), which is not sufficient to pinpoint small damaged areas. As a result, issues such as “the location written in the report does not match the actual site, causing extra work to confirm” or “it is impossible to accurately identify the damaged part from the photo alone” can occur.

On the other hand, by adopting geotagged photos you can retain quantified, accurate location data for each photo. Writing in a report “a crack at the base of pier A2 of the XX bridge” is ambiguous, but if you attach coordinates, anyone can point to the same location using a common reference. If accurate location information is tagged to each photo, there will be no confusion when reviewing photos later, and the accuracy and reliability of records will dramatically improve.

Benefits of managing geotagged photos on a map

Recordkeeping with geotagged photos not only eliminates on-site memo work but also brings various benefits to subsequent data management and the entire inspection workflow. The main effects are summarized below.

• Objective and reliable location identification: When numeric coordinates are assigned to photos, spatial ambiguity in reports is eliminated. Without relying on text or human memory, anyone can correctly identify the same point, preventing misunderstandings or misinterpretations about which location a photo depicts.

• Easier tracking and comparison of inspection history: If damage locations or measurement points are recorded with coordinates as tags, you can reinspect exactly the same location in subsequent inspections and quantitatively compare changes over time. If time-series photo data are overlaid on maps or drawings, distribution of damage and deterioration trends can be visualized intuitively and accurately.

• Improved efficiency of recordkeeping and error prevention: If location information is recorded automatically when taking photos, workers do not need to take handwritten notes or later add location descriptions to each photo. This prevents number entry mistakes and loss of notes, improving recording accuracy and operational efficiency both on site and in the office. Also, because photo and coordinate-linked data are easy to organize and search, time spent finding needed information later is reduced.

• Digital integration and simplified reporting: Numeric coordinate data are easy to integrate with electronic maps, CAD drawings, GIS (geographic information systems), and asset management systems. For example, loading acquired photo locations into dedicated software and plotting them on a map can automatically place hundreds of photos on a map in an instant, eliminating manual assignment work. Integrating inspection records simplifies photo organization and report creation. Using geotagged photo data, photos can be automatically assigned to corresponding spots on prepared drawings, and reports can be generated with one click based on inspection results. Automated processing enabled by digital data will greatly reduce the reporting workload.

How to manage geotagged photos on a map all at once

So, how can you actually use geotagged photos to make inspection work more efficient? Here are the basic steps and usage scenarios.

• Obtain location information at the time of shooting: As a prerequisite, photo data must include location coordinates. Fortunately, modern smartphones and tablets are equipped with high-performance GPS, and if you turn on location (geotag) saving in the camera app settings, latitude and longitude will be automatically recorded in the photo at the time of shooting. You can also use a dedicated digital camera with built-in GPS. The important thing is to ensure location recording is not missed during inspections. If you are concerned about the GPS accuracy of your device or are working indoors where GPS signals do not reach, consider using a high-precision positioning device as described below.

• Plot photo data on a map: After inspection work, manage the collected photos on a map. If photos include location information in Exif, there are tools and software that can read this and display markers on a map. For example, simply loading a photo folder into desktop mapping software or a cloud service can automatically generate a map with pins at the shooting locations. Dedicated infrastructure inspection support systems let you upload photos to easily create a map that shows which photos were taken where. Even for wide-area patrol inspections, the shooting points become obvious on the map, allowing intuitive checks for “missed shots” and grasping the distribution of anomalies.

• Use the photo map to improve operations: Once photos are centrally managed on a map, actively use that data for field work and reporting. For example, clicking a marker on the map instantly shows the corresponding photo and notes, enabling you to understand on-site conditions spatially while in the office. Sharing map data among stakeholders makes it possible to visually share site conditions that are hard to convey by words or text. Analyzing accumulated history data on the map can reveal trends such as where defects occur more frequently. As a further application, using location-tagged photo data for AR display allows you to point a smartphone or tablet camera at a site and immediately see what kind of defects occurred where in the past. Combining digital maps and photos dramatically streamlines the entire process from inspection planning to execution, recording, analysis, and reporting.

Simple surveying with LRTK

You should now understand how adopting geotagged photos helps promote DX in inspection work. Recently, there has been increasing interest in taking this further by easily using high-precision positioning technology in the field. A representative example is simple surveying with LRTK, which combines a smartphone with a small GNSS receiver.

LRTK is a solution consisting of an ultra-compact RTK-GNSS positioning device that can be attached to a smartphone and a dedicated app. RTK (Real-Time Kinematic) is a technology that corrects GPS positioning errors in real time, dramatically improving typical meter-level positioning errors to accuracy of several centimeters (several in). Whereas RTK surveying traditionally required specialized surveying equipment and skilled technicians, LRTK enables anyone to perform it easily with just a smartphone. Because you can obtain accurate coordinates simultaneously when taking photos with your smartphone camera, geotagged photos can be recorded with higher precision and reliability.

For example, when photographing cracks on a concrete surface during bridge inspection, using LRTK allows you to link the photo data to the exact location of the pier down to the centimeter level (inch-level). When viewing the photos later on a digital map or structural drawing, they are pinned to the precise location, preventing situations where you cannot tell which part the photo shows. LRTK systems also provide a “positioned photo” feature that saves photos together with coordinate data (and camera orientation), so each photo’s location (and camera direction) can be recorded. The acquired data can then be automatically assigned to corresponding places on electronic drawings or compiled into reports, reducing effort in report creation.

In addition, LRTK supports not only still photography but also 3D scanning using smartphone sensors. By simply walking with a smartphone on site, you can acquire high-precision point cloud data that can be applied to as-built measurements and displacement measurements. The acquired 3D data and geotagged photos can be uploaded to the cloud and immediately shared with stakeholders, enabling on-the-spot dimensional checks and repair planning. Moreover, LRTK supports Japan’s Quasi-Zenith Satellite System “Michibiki” (CLAS), allowing centimeter-class positioning even in mountainous areas or sites outside communication coverage by receiving augmentation signals from satellites. Truly, an era has arrived where “anyone, anywhere, anytime” can handle high-precision location information.

By using LRTK, you can increase the precision of inspection records with geotagged photos, and field personnel themselves can perform positioning work without surveying specialists. As a trump card to further raise the efficiency and quality of inspection work, simple surveying with LRTK is extremely promising. If you are interested, please also check the [LRTK Phone official site](https://www.lefixea.com/phone).

FAQ

Q: What is a geotagged photo? A: A geotagged photo is a photo in which the shooting location’s latitude and longitude and other location information are included in the photo data. Each photo has data recording “when and where it was taken,” allowing the location to be objectively identified when reviewing photos later.

Q: Can I take photos with location information using only a smartphone? A: Yes. Many smartphones have built-in GPS, and if you enable location recording in the camera settings, latitude and longitude will be automatically saved in the photo at the time of shooting. However, the positioning accuracy of built-in smartphone GPS is generally said to be on the order of several meters (several ft). Therefore, for inspections inside large facilities or for recording small deterioration points, a smartphone alone may only provide coarse location information. When high accuracy is required, using an attachable high-precision GPS device for smartphones (for example LRTK) is effective. With such devices, you can capture smartphone photos with centimeter-level accuracy (inch-level).

Q: How can I display photos on a map? A: If photo files contain location information (latitude and longitude), there are software and services that can read it and plot the photos on a map. For example, loading photos into desktop mapping software or GIS will automatically display markers at each photo’s shooting location. If you use a specialized infrastructure management system, uploading photo data may generate an inspection location map. Try free software or online map services first, and choose tools that fit your workflow based on usability.

Q: Can I add coordinate information to photos taken in the past? A: Yes. Photo management software and Exif editing tools can add location information to photos. However, recalling and inputting accurate locations afterward is time-consuming and prone to mistakes, so it is still best to record location information at the time of shooting. If you used a camera without GPS, you can simultaneously record a travel log with a GPS logger app and later match photo timestamps to the track to determine positions, but considering the effort, it is more practical to use GPS-enabled equipment or a smartphone from the start.

Q: Is it difficult to introduce a new digital management system on site? A: Recent systems emphasize ease of use, and many can be handled without special IT skills. There are inspection support apps that feel like smartphone apps, and devices such as LRTK that attach to smartphones provide one-touch attachment and automatic positioning for intuitive use. Start by trialing in some sites and let staff become familiar with the operation to achieve smooth adoption. Once tried, you will likely find the convenience of managing photos on a map indispensable.

Q: What is LRTK? A: LRTK is a set of a small device and an app that can turn a smartphone into a high-precision positioning instrument. Attached to a smartphone, it uses RTK-GNSS technology to achieve centimeter-level positioning. This allows you to acquire accurate coordinates when taking photos with a smartphone, and to perform 3D scans using the phone’s camera or LiDAR sensor. With LRTK, even people without surveying expertise can easily record and use high-precision location data, greatly improving the efficiency of inspection and survey work. For more details, refer to the LRTK official site.