Easy Point Cloud Surveying with a Smartphone: 3D Data Acquisition Made Simple

Table of contents

• What is point cloud surveying?

• Differences from traditional surveying methods

• How to acquire 3D point clouds with a smartphone

• Benefits of smartphone-based point cloud surveying

• Challenges and limitations of smartphone point cloud surveying

• Advances in smartphone surveying technology

• LRTK: enabling easy surveying with a smartphone

• Conclusion

• FAQ

When you hear “surveying,” you might imagine a qualified specialist using expensive equipment. However, thanks to advances in smartphone technology in recent years, an era has arrived in which anyone can easily acquire 3D surveying data (point cloud data). This article explains how to perform point cloud surveying with a smartphone, its benefits, and how it differs from traditional methods. At the end, we also introduce LRTK, a cutting-edge surveying solution that leverages smartphones.

What is point cloud surveying?

Point cloud surveying is a surveying method that records the shape of an object as a collection of many points (point cloud data). Each point in point cloud data contains XYZ coordinates, representing surfaces such as buildings or terrain with countless points. For example, if you capture a building façade as a point cloud, you can represent even the minute irregularities on that wall in three dimensions.

Traditional surveying measured only selected key points and produced drawings, but point cloud surveying records the entire object as a high-density assemblage of points, allowing you to view arbitrary cross-sections or take dimensions later. In other words, it’s like digitally copying everything at the site as a set of points. Because of this, the amount of data obtained is enormous, but a major characteristic is that it can preserve the site’s detailed conditions comprehensively.

Acquired 3D point cloud data is used in civil engineering and architecture to create 3D models called BIM/CIM and for construction as-built verification (checking the shape of finished work), and it is becoming an important technology for promoting DX (digital transformation) across the construction industry.

In the past, point cloud surveying was commonly performed using dedicated, expensive equipment such as 3D laser scanners. However, due to technological progress and cost reductions, drones, vehicle-mounted systems, and even smartphones can now acquire point clouds, making point cloud surveying more accessible.

Differences from traditional surveying methods

Traditional surveying typically uses instruments like total stations or surveying GPS, recording coordinates point by point for each location to be measured. For example, one would measure important locations such as building corners or boundary points and create drawings and cross-sections from that set of points. While this yields high accuracy, trying to record a large area in detail requires enormous time and effort.

In contrast, point cloud surveying uses sensors to continuously and surface-wise scan object surfaces, recording them as collections of thousands to millions of points. This allows you to capture the site’s shape in its entirety, including details that might have been overlooked with traditional methods, reducing the chance of later regretting not having measured a particular part. However, a major difference from traditional methods is that the voluminous point cloud data obtained must be processed into architectural drawings or models separately. In other words, point cloud surveying reduces the burden of measurement work while increasing the data processing steps.

How to acquire 3D point clouds with a smartphone

So how can you acquire 3D point cloud data with a smartphone? Broadly speaking, there are two approaches. One is called photogrammetry, in which you take photos of the object from various angles with the smartphone camera and reconstruct the 3D shape by analyzing multiple photos. With a dedicated app, you can walk around the object as if shooting a video, and a point cloud model is generated automatically (processing may be done in the cloud). Photogrammetry can be used on smartphones without special sensors and its advantage is that you can photograph a wide area and later obtain a high-density point cloud.

The other approach uses the smartphone’s built-in LiDAR sensor. Some recent high-end smartphones include compact infrared laser-based depth sensors. With a LiDAR sensor, laser light is emitted toward the object and distance is measured directly from the return time, enabling real-time point cloud acquisition on site. The scanned point cloud is displayed incrementally on the smartphone screen, providing assurance that no areas are missed. However, the measurement range of smartphone-mounted LiDAR is limited to a few meters (a few ft), so it is mainly suitable for indoor or close-range objects.

In these methods, the smartphone’s internal sensors (gyros and accelerometers) record its position and orientation, combining those with photos or LiDAR point clouds to reconstruct the overall shape in 3D space. The final point cloud data is expressed in a coordinate system relative to the smartphone, but by linking to known reference points or combining with high-precision GNSS devices discussed later, it is possible to align it to real-world coordinates.

Benefits of smartphone-based point cloud surveying

There are many advantages to conducting point cloud surveying with a smartphone. The main benefits are listed below.

• Low cost: Surveying equipment that used to require investments on the order of millions of yen can be replaced by a smartphone and an app, and sometimes inexpensive add-on devices. Because you can use the smartphone you already have, the initial adoption barrier is greatly reduced.

• Portability and ease: Smartphones are compact, lightweight, and always carried by users. You can take one out and start measuring whenever needed on site. The lack of heavy equipment to transport and set up makes it convenient for quick measurements.

• Ease of operation: Smartphone surveying apps have intuitive user interfaces, allowing operation without specialized equipment training. Following on-screen guidance to move the device is sufficient to acquire data, making it easy for people with limited surveying experience to adopt.

• Rapid data acquisition: Point cloud scans can complete wide-area measurements in a short time. Points that would be impossible to collect by measuring one point at a time manually can sometimes be gathered in a matter of minutes, dramatically accelerating site assessment and measurement workflows.

• Versatility: Smartphones offer many functions beyond surveying. You can simultaneously record high-quality photos and notes, or calculate distances, areas, and volumes from the acquired point cloud on the spot, enabling multifunctional use. Using AR features to overlay design drawings on current conditions is another way to support on-site decision-making.

• Easy data sharing: Data acquired on a smartphone can be uploaded to the cloud on the spot or sent immediately by email or chat. There’s no need to return to the office and transfer files to a PC, so stakeholders can quickly share information and streamline downstream communication.

Challenges and limitations of smartphone point cloud surveying

While smartphone surveying is convenient, there are challenges and limitations to be aware of. The main points to consider are listed below.

• Accuracy and positioning issues: Built-in smartphone GPS typically has accuracy on the order of a few meters (a few ft), making it difficult to assign precise real-world coordinates to the acquired point cloud. Photogrammetry and smartphone LiDAR may introduce scale and alignment errors, so additional correction work may be required when high accuracy is needed.

• Measurement range limitations: Smartphone sensors have limited measurement ranges. Built-in LiDAR typically only reaches a few meters (a few ft), making it difficult to measure vast sites or tall structures in a single scan. Covering large areas may require dividing the area and conducting multiple scans, which demands extra effort and planning.

• Environmental influences: Measurement quality depends on environmental conditions. Photo-based methods lose accuracy when the object lacks texture or there is insufficient light. Materials that transmit or reflect light, like glass or water surfaces, do not yield good point clouds. Outdoor LiDAR usage can suffer from noise under strong direct sunlight, and rain can make measurement itself difficult.

• Data processing and size: High-density point cloud data produce large files, and a smartphone alone has limitations for processing and storage. Generating or displaying point clouds can take time and may consume device storage. Consider strategies for handling large data volumes such as decimation or using cloud services. Long scans also drain battery quickly, so plan for power supply management.

Advances in smartphone surveying technology

Although these challenges exist, smartphone surveying technologies have rapidly advanced in recent years, and these constraints are gradually being overcome. Improvements in smartphone performance are also supporting 3D surveying. Recent smartphones feature higher-resolution cameras, built-in depth sensors like LiDAR, faster processors enabling real-time 3D processing, and support for dual-frequency GNSS to receive satellite signals with higher accuracy. These enhancements are strengthening capabilities that can be used for surveying year by year, making it increasingly possible to acquire high-density point clouds and perform on-device data processing.

The development of peripheral technologies that integrate with smartphones is also notable. High-performance sensors and receivers that attach to smartphones have been introduced one after another. For example, long-range laser scanners can be connected to smartphones to measure wide areas, and RTK-type high-precision GNSS receivers can be mounted on smartphones to achieve centimeter-level positioning. Incorporating these technologies dramatically improves the accuracy and applicability of point clouds acquired with smartphones.

LRTK: enabling easy surveying with a smartphone

A representative example of such new technologies is “LRTK.” LRTK is a solution that transforms a smartphone into a powerful surveying tool by attaching a compact high-precision GNSS receiver to the smartphone and using a dedicated app. It supports RTK (real-time kinematic) satellite positioning, enabling position information to be obtained with centimeter-level accuracy.

With LRTK, tasks that previously required specialized equipment and advanced skills can be done with just a smartphone. For example, you can simply hold an LRTK-equipped smartphone over a point you want to measure and press a button to accurately record that point’s latitude, longitude, and elevation. The measured positions are automatically converted to Japan’s plane rectangular coordinate system and elevation system, and saved to the cloud along with the timestamp and notes. The app can immediately calculate distances between multiple recorded points and compute area and volume.

Moreover, by integrating with the smartphone camera and LiDAR, you can walk around the site and acquire 3D point cloud data. Combining the absolute coordinates measured by LRTK with point clouds obtained from the smartphone’s sensors allows you to quickly generate full-scale point cloud models of buildings and terrain. Using that point cloud, you can immediately compute earthwork volumes (cut and fill) and check construction results by overlaying design data. Tasks that previously required separate steps—drawing creation and quantity calculations—can be completed on site, which is a significant advantage.

Survey data obtained with LRTK can be shared instantly via the cloud, allowing office staff to check results in real time. It is also possible to use the smartphone’s AR features to project design lines or the positions of existing buried utilities onto the acquired point cloud and display them on site. This makes it easy to intuitively grasp discrepancies between design and actual conditions and plan work that avoids buried facilities, thereby directly supporting on-site decision-making.

LRTK devices are multifunctional and high-performance, yet the hardware is lightweight and compact—only a few hundred grams—and pocketable. They have built-in batteries and operate cablelessly. Their price is far more accessible compared to traditional surveying equipment, making them an ideal on-site tool for the “one person, one device” era. Designed to be usable by non-specialist surveyors, LRTK enables construction managers and field workers to perform measurements as needed, directly improving productivity.

Conclusion

Smartphone-based point cloud surveying is turning 3D measurement from a specialist’s domain into something anyone can use. The ability to cheaply and easily obtain detailed 3D data on site contributes greatly to streamlining a wide range of field operations such as construction management, design, and inspection.

Of course, smartphone surveying cannot replace all cases. Measurements that require millimeter-level accuracy or legally mandated surveying work will still require traditional high-precision equipment and skilled surveyors. However, for routine measurements and on-site information gathering, the ability for anyone to quickly acquire data with a smartphone could revolutionize site operations. As devices and software continue to evolve and the achievable accuracy and range of smartphone surveying expand, the barriers to surveying may fall further and an era in which “measuring” is commonplace could arrive.

If you want to start point cloud surveying with a smartphone, try a small area first to get a feel for operation and data processing. Leveraging advanced tools like LRTK can enable higher accuracy and efficiency, making “surveying anyone can do” a reality. Consider adopting smartphone surveying to advance DX (digital transformation) on your sites.

FAQ

Q: How does surveying with a smartphone work? A: Smartphones contain cameras and various sensors. For example, multiple photos can be used to reconstruct a 3D shape, or a LiDAR sensor can acquire a point cloud by emitting light and measuring distance. Internal gyros and GPS record the device’s position and orientation, and combining this information enables measurement of the surrounding 3D environment.

Q: What accuracy can smartphone surveying achieve? A: It depends on the method and conditions. Photogrammetry can produce errors on the order of several centimeters to several tens of centimeters (a few in to several tens of in), depending on object size and shooting method. Smartphone LiDAR can achieve accuracy within a few centimeters (within a few in) at close range. By combining RTK-capable devices (such as LRTK), positional accuracy can be improved to the centimeter level (half-inch accuracy).

Q: In what ways is it inferior to professional surveying equipment? A: Generally, a standalone smartphone has shorter measurement range and lower accuracy and point density compared to dedicated laser scanners. For wide-area surveying or tasks requiring millimeter-level accuracy, specialized equipment and professional surveyors are still necessary. However, combining external sensors with smartphones has narrowed this gap, and under certain conditions smartphones can achieve practically useful accuracy.

Q: Can someone without surveying knowledge use it? A: Surveying apps for smartphones are designed to be intuitive, and basic measurements and point cloud acquisition can be performed without specialized knowledge. Following the app guide to move the smartphone is sufficient for beginners. However, having basic surveying or civil engineering knowledge helps to correctly interpret and make use of the acquired data.

Q: What do I need to use LRTK? A: To use LRTK you need a compatible smartphone (iPhone or Android), the LRTK device itself, and the dedicated app. Attach the device to the smartphone, launch the app, and configure required settings (such as GNSS correction input) to start high-precision positioning and point cloud measurement. In Japan, using high-precision positioning services provided via satellite (for example, QZSS’s CLAS) can ensure centimeter-class accuracy even at sites without internet connectivity.

Q: How can point cloud data acquired with a smartphone be used? A: Acquired point cloud data can be loaded into dedicated software to create 3D models of terrain and structures, or overlaid with CAD drawings to check design discrepancies. You can also generate cross-sections or plan views from point clouds to measure dimensions. Point clouds exported from a smartphone can be saved in common formats such as LAS or PLY for use in various analysis and design software.