7 Points to Streamline 3D Preservation of Cultural Heritage Using Smartphone LiDAR

In practical work related to 3D preservation of cultural heritage, a major challenge is how much the burden of on-site work can be reduced while ensuring the accuracy of records. Traditionally, projects have often focused on specialized equipment, making preparation, transport, measurement, and data processing time-consuming; however, in recent years there has been a growing movement to use smartphone LiDAR to streamline initial recording and supplementary 3D preservation.

However, precisely because smartphone LiDAR is convenient, misuse can undermine the reproducibility of recordings and their value for long-term preservation. Cultural heritage, once lost, cannot be completely restored, so simply being able to measure quickly is not sufficient. What is needed is an approach that balances efficiency with the quality of the records.

In this article, aimed at practitioners searching for "smartphone LiDAR cultural heritage", I organize and explain the basic concepts to keep in mind when advancing 3D preservation of cultural heritage, and seven points to reduce the likelihood of failure in the field. From a practical perspective, I summarize how smartphone LiDAR should be positioned for various uses—field surveys, preservation records, before-and-after comparisons for restoration, and preparing archives for public access.

Table of Contents

• Why smartphone LiDAR is gaining attention for 3D preservation of cultural heritage

• Point 1: Define the purpose of the record before taking measurements

• Point 2: Determine the scope of application according to the material and shape of the object

• Point 3: Prior preparation is important for streamlining on-site work

• Point 4 Design a scanning flow to prevent missed items

• Point 5 Align the reference standards for location data and dimensions to improve reusability

• Point 6: Consider 3D preservation to include data organization and storage design.

• Point 7: Establish workflows for sharing and updating with long-term operation in mind

• Summary for advancing 3D preservation of cultural heritage using smartphone LiDAR

Why smartphone LiDAR is attracting attention for 3D preservation of cultural heritage

In preservation records for cultural properties, it is standard practice to combine multiple types of information—photographs, drawings, written descriptions, and measurement data—to document condition. However, photographs alone can struggle to convey depth and three-dimensional form adequately, and drawings alone can make it difficult to intuitively grasp fine surface irregularities and changes caused by aging. For this reason, there is growing demand to supplement records with three-dimensional data so that the current condition can be documented more comprehensively.

Among these, the reason smartphone LiDAR is attracting attention is its portability and rapid initial response. It makes it easy to quickly record points of interest on site, and because it can be used nimbly in confined spaces or areas with elevation differences, the barrier to adoption in cultural property surveys and conservation activities is relatively low. The ability to capture three-dimensional shapes without extensive preparations is a major advantage as an entry point to preservation.

Also, at cultural heritage sites, it is not always possible to secure the same staffing or the same budget for every survey. There are many cases where on-site recording must be carried out by a limited number of people in a short time, and the value of easy-to-use tools increases, especially for primary and supplementary records, comparisons before and after restoration, and monitoring locations at risk of damage. Smartphone LiDAR is well suited to uses such as "initial documentation," "immediate on-site verification," and "tracking changes."

On the other hand, in the 3D preservation of cultural heritage, it is necessary to separate the convenience of equipment from the validity of the documentation. Smartphone LiDAR is not a panacea; with extremely fine sculptural details, deep shadows, minute losses or chips, mirror-like reflective surfaces, and uniform, featureless planes, data loss and distortion are likely to occur. In other words, it is important to regard smartphone LiDAR not as a tool to replace everything, but as a tool that streamlines the overall process when used selectively according to the purpose.

What is truly necessary in the preservation of cultural properties is to determine who will ultimately use the data, in what situations it will be referenced, and how much reproducibility is required. Whether it will be used to create supplemental diagrams for reports, as baseline material for restoration plans, or as a foundational archive for future re-surveys will change the required granularity of measurements and the methods of organization. If you begin collecting data on-site with these aspects left ambiguous, it often leads to problems later such as “the information we want to see is lacking,” “the files are large but hard to use,” and “the data cannot be compared.”

Therefore, to streamline 3D preservation of cultural heritage using smartphone LiDAR, it is essential to adopt an approach that, rather than merely focusing on faster scanning techniques, clarifies what should be preserved and designs the on-site work and organizing/post-processing tasks as an integrated whole. From the next chapter, we will examine those practical points in order.

Point 1 Define the purpose of recording before taking measurements

When aiming to streamline 3D preservation of cultural heritage, a common initial tendency at many sites is that once the equipment is available, people think, "let's just scan the whole thing for now." However, that approach does not improve efficiency; it increases unnecessary data and makes downstream processing more time-consuming. The first thing to do is not to carry out measurements but to define the purpose of the documentation.

For example, if the objective is to ascertain the current condition of a cultural property, emphasis is placed on the consistency of the overall shape and on capturing the dimensions of major elements. If the objective is to compare before and after restoration, reproducibility—i.e., the ability to repeatedly acquire data with the same spatial relationships and the same extent—is important. If the objective is a digital exhibition for visitors or for educational use, not only rigorous surveying accuracy but also visual clarity and legibility are emphasized. In this way, depending on the purpose, both the granularity of the data to be acquired and what needs to be considered on site change.

In practice, surveys of cultural properties are often carried out by multiple stakeholders, and the information needed differs slightly among those responsible for conservation, investigation, restoration, and management. Therefore, it is important to put into words "what to record" before entering the site. Is it the overall view of the object, the shape of degraded areas, the relationship with the installation position, or changes in condition such as cracks, delamination, tilting, or settlement? If this is clarified, measurements can be taken that are neither excessive nor insufficient, which in turn leads to reduced working time.

What's even more important is to consider the role of 3D preservation alongside other recording methods. If you try to explain everything using only three-dimensional data, you tend to extend the measurement range beyond what is necessary. In practice, some information is adequately captured by photographs, some should be supplemented in writing, and some should be represented in plans or cross-sections. Designing smartphone LiDAR 3D recording as one means to complement these other methods will more readily improve the overall quality of the preservation records.

To reduce uncertainty on-site, it can be effective to separate in advance the "scope that must be retained" and the "scope to retain if capacity allows." If the mandatory scope is clear, you can reliably secure the minimally necessary records even on days when on-site conditions are difficult. Conversely, if you treat everything—including the optional scope—with the same weight, you may end up leaving critical areas half-finished as a result of being pressed by travel time and dealing with peripheral tasks.

3D preservation of cultural heritage requires capturing the necessary information without loss rather than "capturing broadly" precisely because the objects themselves have high value. The mobility of smartphone LiDAR leads to greater efficiency only when combined with that approach. Defining the purpose in advance is not only a way to shorten on-site work; it is also the first condition for creating records that can be used later.

Point 2: Determine the scope of applicability based on the material and shape of the target object

When using smartphone LiDAR for 3D preservation of cultural heritage, a decisive factor for whether efficiency can be achieved is correctly judging what it is suitable for and what it is not. If this is mistaken, you may spend a lot of measurement time yet fail to obtain data of sufficient quality, requiring a re-survey.

In general, objects that are relatively easy to record stably are those whose contours are easy to grasp and that have a moderate amount of surface features. For example, stone monuments, stone walls, foundation sections, parts of buildings, and structural elements with relatively large, well-defined shapes can be well suited to smartphone LiDAR for capturing overall form and confirming positional relationships. In particular, rapid 3D digitization is useful for current-condition recording, preliminary planning, before-and-after comparisons for relocation, and identifying the locations of damaged areas.

On the other hand, with fine carvings, shallow incisions, near-mirror materials, strongly reflective surfaces, wet surfaces, highly translucent materials, or extremely dark locations, the shape can become unstable and surface details may not be adequately captured. For many cultural properties, differences in material are directly linked to their value, and subtle changes on the surface often constitute important information. For such objects, judgments should not be based solely on the results of smartphone LiDAR; they should be treated in combination with supplementary photographs and measurement records.

Also, attention must be paid to the complexity of shapes. On intricate backsides, deep recesses, narrow gaps, and areas with many protrusions, unseen portions can remain unrecorded. In the preservation of cultural heritage, it is problematic if unrecorded areas are confused with actual damage. Therefore, when dealing with complex shapes, it is necessary to proceed while verifying on-site which areas have been recorded and which have not.

The important point here is not to judge smartphone LiDAR in a binary way of usable or not. Instead of a simple usable/unusable choice, you need to establish where it is sufficiently helpful and where other methods should be used to supplement it. For example, while it may be adequate for preserving overall shape, additional close-range recording is often required to capture fine surface damage. By dividing roles in this way, you can leverage the strengths of smartphone LiDAR while also maintaining the reliability of cultural heritage documentation.

In practical work on cultural properties, not only the object itself but its relationship with the surrounding environment is important. Installation conditions inside a building, the positional relationship with a pedestal, distances to walkways and surrounding walls, site conditions on sloping terrain, and other surrounding information can affect preservation-related decisions. Smartphone LiDAR also has the advantage of making it easy to capture this "object + surroundings" relationship as a whole. Rather than being dedicated to fine details, if it is considered as a means to grasp the condition of an entire space, its range of use expands.

In other words, the prerequisite for improving efficiency is to assess the target’s material and shape and then decide what to entrust to the smartphone LiDAR. Not trying to make it do everything is, ultimately, the least wasteful way to proceed.

Point 3: Advance preparation is important for streamlining on-site work

If you want to shorten on-site time for 3D preservation of cultural heritage, the most effective factor is not what you do on the day but the preparation beforehand. Smartphone LiDAR gives the impression that it can be used immediately after startup, but at cultural heritage sites insufficient preparation directly leads to missed records and the need for revisits. Efficiency should be considered not simply as shortening measurement time but as reducing rework.

The first thing to clarify is the scope of on-site work. The grounds of cultural properties may not allow free movement due to access conditions, visitor routes, protected zones, scaffold restrictions, and other constraints. If you don’t identify the areas where movement is possible in advance, you may have to change measurement routes suddenly on site, which makes omissions or duplicate captures more likely. In particular, cultural properties require consideration of contact risks and you may not be able to approach the subject closely, so it’s important to plan in advance from where and at what angles you will capture it.

Next, what we need to check is the lighting environment and the time of day for the work. For outdoor cultural heritage, direct sunlight, backlighting, shifting tree shade, and large contrasts in surrounding brightness have a major effect. Indoors, dark areas and localized lighting can affect results. Smartphone LiDAR itself is a means of capturing shape, but since it will be used in combination with images and visual checks referred to later, checking in advance which time of day is suitable for recording will stabilize on-site decision-making.

Also, 3D preservation of cultural properties does not end with the object itself. You need to carry out the shooting order, object numbering, record notes, supplementary photos, dimension checks, and annotations of damaged areas as an integrated process. Therefore, on-site, if it is not clear “what to capture next and what to do afterwards,” you often end up with data that exists but cannot be organized. Deciding in advance how to assign object numbers, how to structure storage folders, and the rules for linking site notes will greatly reduce the time required for organization.

Cultural properties are highly individual, and conditions differ each time. Precisely for that reason, deciding on a set of general preparatory items improves efficiency. For example, checking in advance the item's name, location, conservation purpose, priority areas, surrounding obstacles, the need for supplementary records, and the difficulty of revisiting reduces uncertainty on site. Reducing hesitation prevents judgment errors more than operational errors.

Furthermore, at cultural heritage sites, more time is often spent on considerations for the surroundings and coordination with stakeholders than on the survey itself. Permit conditions, whether to make the results public, visitor handling, protective measures, and whether temporary protection is required — these non-recording issues must also be organized in advance. While smartphone LiDAR can easily reduce labor, its very ease of use can become a pitfall, causing people to underestimate the necessary preparations.

A truly efficient site is not one where workers move quickly, but one where there is little time spent thinking on-site. In 3D preservation of cultural heritage, that difference directly translates into quality. Careful advance preparation ultimately delivers the greatest time savings.

Point 4 Design a scanning workflow to prevent missed scans

When recording cultural heritage with a smartphone LiDAR, what determines on-site efficiency is the scanning path design: the order in which you scan, the distances at which you view the subject, and the directions from which you approach it. Even if you're familiar with the operation itself, if the scanning path is unclear you may walk the same areas repeatedly or miss key parts, so despite spending time the level of completeness may not improve.

Especially in 3D preservation of cultural heritage, a major problem is that oversights tend to be discovered only later. Even if data seem to have been captured sufficiently on site, when reviewing them at the office you may find parts of the rear missing, the connection to the base unclear, or insufficient close-range information about areas showing deterioration. Because cultural heritage is often difficult to revisit, it is necessary to plan, from the outset, a workflow that can be completed on site.

The basic idea is to work from the whole to the parts. First, cover the area that allows you to understand the entire subject and the positional relationships of its surroundings, then move closer to the important parts to fill in missing information; this flow makes it easier to reduce omissions. If you focus on close-ups from the start, you may capture details but it will become harder to understand their relationship to the whole, making them difficult to use when organizing.

Also, when documenting cultural properties, there are many angles that later prove important besides the front: the sides, the back, the junctions with the plinth, areas close to the top surface, and the points where it meets the ground. Especially for checking deterioration and tilt, lateral information that is difficult to grasp from frontal photographs is required, so it is important to be conscious of acquiring images while circling around. However, simply making one circuit is not enough; if you plan in advance where to change height and which angles to use to fill in gaps, you can avoid measurements that take longer than necessary.

One thing that is often overlooked in circulation design is the relationship with the background. If you focus too much on the individual object alone, you end up lacking positional information relative to surrounding walls, floors, and foundations, which later makes it difficult to interpret dimensions and layout relationships. In cultural heritage conservation, not only the object itself but also where and how it existed can be important, so a scanning sequence that preserves the spatial context is required.

Furthermore, on site it is necessary to make a habit of checking capture results in real time. What is important for efficiently preserving cultural heritage in 3D is not to simply capture and walk away. It is far more efficient to check the capture coverage at key points and, if there are holes or distortions, fill them in on the spot rather than revisiting later. Especially on surfaces where identical shapes repeat or in areas with strong shadows, unacquired portions tend to remain more than they appear, so you should plan your workflow and movement routes assuming you will check as you go.

Workflows are more stable when you set simple rules for each subject rather than relying on familiarity. If you standardize the order of capture—overall view, the four sides, the base, areas of deterioration, and the relationship with the surroundings—it becomes easier to maintain consistent quality even when personnel change. Because personal methods tend not to accumulate in cultural heritage documentation, standardizing workflows also helps even out the on-site workload.

The advantage of smartphone LiDAR is that it lets you move freely. However, precisely because it allows free movement, moving without a plan reduces efficiency. For 3D preservation of cultural heritage, planning the movement path before entering the site is the most reliable way to improve efficiency.

Point 5 Standardize location and dimension references to make reuse easier

What is often overlooked in 3D preservation of cultural heritage is that aligning standards for easy future comparison is more important than simply acquiring the data itself. Even if smartphone LiDAR can record the on-site shape, ambiguous references for positional information and measurements make it difficult to use that data for future re-surveys or pre- and post-restoration comparisons. Efficiency also means putting data collected once into a state where it can be used repeatedly.

For example, if you remeasure the same cultural property six months or a year later and the way coordinates are taken or the extent of the measured area differs each time, you can only perform simple visual comparisons. To make clear where changes have occurred, how much displacement there has been, and which parts require attention, a common standard for comparison is necessary. Without this, even if you collect three-dimensional data, it will end up as nothing more than an accumulation of records.

In the conservation of cultural properties, not only the dimensions of the object itself but also its placement and relationship to the surroundings are meaningful.

The current spatial relationships—such as the relationship to the plinth, placement within a building, distance from walls, and vertical fitting—also affect future repairs, relocation, and exhibition planning. For this reason, keeping records that are mindful of positional references will help preserve the value of the data over the long term.

The important point here is not to try to complete all positioning using only smartphone LiDAR. For 3D preservation of cultural heritage, you need an approach that appropriately combines three-dimensional geometry with positional references. For simple documentation of current conditions, relative relationships within the subject can be effective, but if you plan multiple comparisons or integration with other materials, it’s better to have the concept of alignment in mind from the first time—this will make later steps easier.

The approach to dimensions should also be standardized. If you decide which reference to use for the main dimensions that will be frequently referred to later—overall height, width, depth, base dimensions, size of damaged areas, etc.—interpretation of three-dimensional data will be more stable. If you completely postpone verifying dimensions, even if the shape remains, rework is likely to occur when reporting or making comparisons. Cultural properties are often unique items and may not be able to be rechecked on site later, so it is essential to incorporate the approach to major dimensions into the record.

Furthermore, organizing location information is also a good fit for managing the surroundings of cultural properties. For ruins, stone structures, monuments, and historic structures, not only individual records but also the relationships with surrounding facilities and the positional relationships with access routes have preservation value. If you capture shapes with smartphone LiDAR while aligning positional references, it will be easier in the future to link with maps, registers, inspection records, and construction records.

This approach turns small on-site efforts into large reductions in downstream work. 3D preservation of cultural heritage does not end with the deliverables produced on site. Its value expands only when it is reused for subsequent surveys, condition comparisons, preparation of explanatory materials, and so on. That is why aligning standards for positional information and measurements is not only an improvement in quality but is central to long-term efficiency.

Point 6 Think of 3D preservation as including data organization and storage design

When thinking about streamlining 3D preservation of cultural heritage with smartphone LiDAR, it's easy to focus only on capture speed in the field. However, in practice much of the working time is spent organizing data after the site visit. Unless you design the workflow to include how the acquired data will be stored and made reviewable, it won't be genuine efficiency.

A common mistake is that, after collecting large amounts of data, naming conventions are inconsistent, making it unclear later which record corresponds to which cultural property at which point in time. In cultural heritage conservation, information such as the object name, acquisition date, location, part, operator, and purpose becomes important later. If these are not organized, even the three-dimensional data you went to the trouble of preserving will be difficult to search and will end up buried and unused.

Also, for three-dimensional data, contextual information is more important than appearance. Without so‑called metadata—such as the conditions at the time of acquisition, the measurement range, correspondence with supplementary photographs, the presence or absence of missing parts, and locations planned for re‑acquisition—it becomes difficult for a third party to handle the data correctly later. In the field of cultural heritage, staff transfers and gaps in time can occur, so it is important to avoid a situation where only the person who acquired the data understands it.

In preservation planning, organizing data according to its intended use is also effective. For example, separating storage locations by purpose—preservation data that is close to the original, viewing data for stakeholder review, and processed data for reporting—reduces the risk of accidentally overwriting files or sharing unnecessarily large data. Because 3D preservation of cultural heritage often assumes long-term use, thinking in layers from the start helps stabilize operations.

Furthermore, measurements of cultural properties may not end with a single survey. Comparisons at multiple points in time may be necessary—before restoration, during restoration, after restoration, during periodic inspections, and after disasters. If these are organized according to the same rules in a time-series manner, it becomes easier to track changes in condition. Conversely, if the storage methods differ each time, just preparing comparisons becomes time-consuming, leaving little time for the actual analysis.

If you’re serious about improving efficiency, you need to decide on a method of organization not only from the perspective of on-site staff but also from the viewpoint of those who will consult the records later. Records for the preservation of cultural properties are not meant to be closed off to the investigators alone. People with different purposes—such as restorers, managers, those responsible for educational use, and local archives staff—may refer to them. What’s required in such cases is that necessary information can be accessed without needing advanced operations.

Smartphone LiDAR lowers the barrier to capture, but it also tends to generate large amounts of data. That is why it is important to consider data organization and storage design before capture. 3D preservation of cultural heritage is not completed by scanning alone; it only truly becomes meaningful when preserved in a form that can be used in the future. On-site efficiency and the value of archives are, in fact, founded on the same design philosophy.

Point 7 Establish processes for sharing and updating with long-term operation in mind

To ensure that 3D preservation of cultural properties doesn't end as a one-off task but instead continues to function as a valuable, ongoing record, it's essential to establish workflows for sharing and updating. While smartphone LiDAR recording is easy to start with, if the records remain confined to an individual staff member's device or working folder, they are unlikely to be retained as organizational assets.

In the preservation of cultural heritage, referencing past records is important. Only by being able to compare the previous condition, the extent of past repairs, and earlier degradation trends does the meaning of the current state become clear. Therefore, accumulating three-dimensional data in a shareable format and putting in place a system that allows it to be reviewed when necessary is a prerequisite for long-term management.

What is important here is to clarify the purpose of sharing. Not all stakeholders need to edit the same data in detail. In the field of cultural heritage, users have different levels of use: some only need viewing, some only need to compare and verify, and others handle measurement values. Therefore, if you organize who will use it, at what level of granularity, and how frequently before designing the sharing, operations will not become excessive.

Also, without rules for updates, old and new data tend to become mixed. In preservation records for cultural properties, older records are not made unnecessary; rather, preserving past conditions itself has value. Therefore, you need to adopt an approach of accumulating records as a history rather than overwriting. If you record the acquisition date, reason for the update, scope of work, and the changes made, it becomes easier to trace condition changes chronologically.

In practice, when sharing cultural heritage data it is also important to sort what is public and what is not. Not all 3D data can be shared externally; for security, preservation, and management reasons, certain items may require careful handling. For that reason, being mindful of categories such as preservation use, internal review use, and external presentation use will prevent scrambling later. Prioritizing ease of sharing alone can sometimes be insufficient for the proper handling of cultural heritage information.

Moreover, when an update workflow is well established, the strengths of smartphone LiDAR become even more effective. If additional captures can be acquired in the same way during regular inspections or simple re-recordings, it becomes easier to track changes to cultural properties without imposing excessive burdens. Even if large-scale surveys cannot be conducted frequently, continuing supplementary records can aid early detection of anomalies and provide material for restoration decisions.

As we've seen so far, streamlining the 3D preservation of cultural properties is not simply "scanning in a short time." It involves organizing the entire sequence—from objectives, targets, preparation, movement flow, standards, organization, to sharing—into a single workflow and establishing a system that can be sustained without undue burden. Smartphone LiDAR plays a major role in that flow, but operational design is essential to maximize its value.

Summary for advancing 3D preservation of cultural properties using smartphone LiDAR

To make 3D preservation of cultural properties more efficient with smartphone LiDAR, it is important not to rely solely on convenience but to design the workflow to include the purpose of the recording and methods for reuse. First, clarify why the item is being preserved, determine the applicable scope based on the material and shape of the object, and at the site make preparations and streamline movement to prevent omissions. Then, standardize references for location information and dimensions, organize the data in a form that is easy to compare later, and if you can implement procedures that allow long-term sharing and updating, smartphone LiDAR can be a major aid to cultural heritage documentation.

In professional practice in particular, there are many situations where it is important not only to record the three-dimensional form of the cultural property itself but also to document where it is located and how it relates to its surroundings. At every stage—preservation, inspection, restoration, and public use—records with consistent positioning have a wider range of applications. In such situations, reliably establishing positional reference alongside the three-dimensional record greatly influences the efficiency of subsequent processes and the credibility of the records.

In the field of cultural heritage, if you want to supplement smartphone LiDAR shape recording by accurately determining an object's position and establish a foundation that makes comparisons easy during re-surveys, the idea of combining a smartphone-mounted high-precision GNSS positioning device such as LRTK is effective. When on-site coordinates can be verified and the consistency of recorded positions can be maintained, 3D preservation of cultural properties transforms from a mere on-the-spot record into a preservation asset that can be continuously utilized. By quickly capturing form with smartphone LiDAR and underpinning positional certainty with LRTK, the practice of cultural heritage preservation can more easily build a practical, reusable recording system.