What can 3D measurement of buried cultural heritage do? Six practical use cases

At excavation sites for buried cultural heritage, a constant challenge is how to record the information revealed by excavation as accurately as possible and in a form that is easy to reuse later. Once features or artifacts are excavated they cannot be returned to their original state. In the sequence of stripping layers, changing working faces, recording detected features, and ultimately backfilling, it is necessary to preserve the state at each moment with high precision. Against this backdrop, 3D measurement in the field of buried cultural heritage has attracted attention.

Traditional surveyed drawings, photographs, and observation records remain important, but in recent years the use of 3D measurement—which can preserve shapes and spatial relationships in three dimensions—has been spreading in addition to those methods. The term “3D measurement” may sound advanced and specialized, but in practice it offers many benefits directly relevant to fieldwork: improving the accuracy of records, increasing efficiency of on-site work, facilitating information sharing among stakeholders, and enhancing the quality of preservation and public presentation. If introduced with clear objectives, it can be extremely effective.

At the same time, many search users are still gathering information because they do not know exactly what 3D measurement can do, in which situations it is effective, or how it should be used in combination with conventional records. A mere explanation that something can be “left in 3D” does not translate into practical on-site decisions. What is needed is a concrete understanding of which tasks it helps and in what form.

This article organizes, from the perspective of practitioners, what can actually be done with 3D measurement in buried cultural heritage. After covering basic concepts, it introduces six practical use cases that are useful on site, and explains points to be aware of when introducing the method. The content is intended to help those who want to ensure survey results are reliably preserved, improve the quality and reusability of recording work, or plan operations with preservation and utilization in mind.

Table of contents

• What is 3D measurement for buried cultural heritage

• Why 3D measurement is required for recording buried cultural heritage

• Use case 1 Record the overall situation of the excavation area in three dimensions

• Use case 2 Preserve the detailed shape and overlap of features

• Use case 3 Make it easier to share the condition of stratigraphic sections

• Use case 4 Save artifact find contexts with location information

• Use case 5 Facilitate analysis of survey results and report writing

• Use case 6 Make preservation, utilization, and exhibition/education easier

• Principles for making 3D measurement of buried cultural heritage succeed

• Summary

What is 3D measurement for buried cultural heritage

3D measurement for buried cultural heritage records features, artifacts, soil layers, and the overall condition of the survey area revealed by excavation as three-dimensional shape data. Its major characteristic is that it can capture elevation differences, depth, inclinations, overlaps, and spatial relationships that cannot be fully conveyed by planar drawings or photographs.

There are many types of targets to record at buried cultural heritage sites: pit-type features, trench-like features, rows of postholes, stone arrangements, mounds, leveling layers, burned soil, concentrations of artifacts, and so on. The required level of recording detail differs depending on the target. Because the situation changes as excavation progresses, the same location often needs to be recorded at multiple time points. 3D measurement is a powerful means of preserving these changing site conditions as completely as possible and in a way that is easy to verify later.

Typical 3D measurement deliverables include point cloud data representing shapes as a set of three-dimensional points, models reproducing surface geometry, three-dimensional outputs reconstructed from georeferenced photo sets, and graphical materials that can be reused as cross-sections or plan views. The important point is that 3D measurement itself is not the goal, but a method to improve the quality of recording, analysis, sharing, and preservation/utilization.

Also, 3D measurement should be seen as complementing and strengthening traditional records rather than replacing them. Observation records include information that is difficult to quantify—soil texture, inclusions, subtle color variations, and on-site judgments by excavators. Combining hand-drawn plans, notes, and photographs with 3D measurement increases the overall value. In other words, 3D measurement is not a standalone solution but a foundation that raises the accuracy and reusability of buried cultural heritage records as a whole.

Why 3D measurement is required for recording buried cultural heritage

The demand for 3D measurement at buried cultural heritage sites is not simply because it is a new technology. The main reasons are the complexity of recording targets and the increasing need to reuse survey results.

First, excavation sites contain much information that is difficult to grasp from plans and sections alone. The relationships where features cut one another, subtle steps, depths of excavations, how stones are set, and undulations across a surface are fundamentally three-dimensional. Organizing these in two dimensions requires experience, and differences in recorders’ expression easily occur. Using 3D measurement makes it possible to preserve on-site three-dimensional information more objectively, facilitating later analysis and third-party verification.

Second, the diversity of stakeholders has increased. Besides excavators, report writers, supervisors, preservation/utilization managers, local government staff, and education/outreach personnel now all need to use the same results more often. Three-dimensional visualizations are an effective way to share site conditions that are hard to convey with technical terms alone. They make it easier to communicate conditions to those who were not on site, improving the quality of decision-making.

Furthermore, 3D measurement is important from the perspective of record reuse. It is not uncommon for additional analyses to be needed after the survey ends. One might want to revisit section positions during report preparation, re-evaluate the relationships between features, or reinterpret materials from a different research perspective. Often the site has already been backfilled, leaving only the records as the basis for judgment. Having 3D measurement data increases the likelihood of being able to reassess the site with a sense close to being there.

In addition, approaches to preservation and public presentation have changed. Survey results are no longer intended only for specialists; there is growing demand to convey them clearly to local residents, visitors, and educational institutions. Three-dimensional records are excellent explanatory materials and make it easier to visualize the value of surveys. Thus 3D measurement is positioned not only as a means to improve recording accuracy but also as a technology that supports the social use of cultural heritage.

Use case 1 Record the overall situation of the excavation area in three dimensions

One of the most intuitive uses of 3D measurement for buried cultural heritage is recording the overall condition of an excavation area. Because it can capture the extent of the excavation area, the depth of excavation from the ground surface, elevation differences across working faces, distribution of features, and their relationship with surroundings as a single unit, it makes understanding the site’s overall picture easier.

Traditionally, the general situation of an excavation area has been recorded with panoramic photographs and plan views. However, photographs alone can make depth and height differences hard to discern, and plan views may fail to convey surface undulations or the sense of soil volumes. This is especially true at sites where excavation progresses in stages or where multiple working faces exist—there are limits to accurately tracking the overall picture over time with two-dimensional records alone.

With 3D measurement, the entire excavation area can be preserved in three dimensions at milestones such as the start of investigation, intermediate stages, and just before completion. This makes it easier to compare what the situation was at different times. For example, one can track the spread after topsoil removal, the composition of working faces after feature detection, or differences in feature depths after excavations have been completed, treating these as continuous changes. This is useful for reviewing site management and for explanations in reports.

Recording the entire excavation area in three dimensions is also effective for contextualizing individual features. Spatial coherences not apparent when viewing features individually, relationships with surrounding topography, and positions relative to excavation boundaries become more apparent. This is particularly valuable for sites where the areal extent as a surface carries meaning; recording the whole excavation area as unified three-dimensional information has high value.

Moreover, sharing the situation with stakeholders not present on site is easier when three-dimensional data of the whole excavation area is available. Even where plans alone are hard to interpret, three-dimensional records make it intuitive to convey the progress of excavation and the distribution of features. As a result, on-site briefings, consultations, and internal reviews proceed more smoothly, improving not only the quality of records but the manageability of the entire project.

Use case 2 Preserve the detailed shape and overlap of features

3D measurement is particularly powerful when recording the detailed shapes of individual features. At buried cultural heritage sites, feature boundaries are not always clear. Excavation boundaries can be gradual, multiple features can cut one another, or differences in fill can be subtle and hard to judge. When recording such complex situations, three-dimensional information increases the robustness of later verification.

For example, in a pit-type feature where one wants to confirm a slight inclination of a floor or the rise of a wall, there are details that plan and section drawings alone cannot fully express. If the overall shape is preserved by 3D measurement, one can inspect it from arbitrary directions or extract sections at needed positions during analysis. This aids considerations of a feature’s function or formation process.

In features with cutting relationships, it is necessary to carefully determine which is newer, where overlaps occur, and how fill distributions differ. Even if these relationships are visible on site, data can become simplified during the recording process. By conducting 3D measurement, the complex shapes observed on site can be preserved as faithfully as possible, making them more resilient to later re-examination.

3D measurement is also effective for stone-built features where the positional relationships among components are important. How stones are set, differences in height, inclinations, and combinations are often understood only when seen three-dimensionally. While a plan can show arrangement, it may not convey which stone projects how far or how contact relationships are configured. Having 3D records improves the accuracy of reconstruction studies and explanatory materials.

Furthermore, the more complex a feature is, the more understanding tends to depend on the experience of the field personnel. But survey results should not rely solely on the memory of individual staff. Leaving records that allow anyone to re-check to a certain extent is important for organizational recordkeeping. In that sense, three-dimensional records of feature shapes are an important means to support transparency and reproducibility of interpretations.

Use case 3 Make it easier to share the condition of stratigraphic sections

Recording stratigraphic sections is extremely important in buried cultural heritage surveys. Information obtained from section observations—depositional sequences, relationships among excavations, differences in fill, and traces of leveling or reclamation—is essential for understanding site formation processes. At the same time, sections are often time-sensitive: collapse, drying, or movement to the next work stage can prevent thorough re-examination. This is where 3D measurement is useful.

Section drawings have long been an important recording method, but expression varies depending on what the recorder emphasized or omitted. Observation skills and drafting techniques are of course necessary, but it is not easy to convey subtle irregularities and the continuity of the entire section perfectly. When 3D measurement is used alongside sectional records, the shape of the section surface itself and its relationship to surroundings can be preserved three-dimensionally, making it powerful material to complement drawings and photographs.

This is especially effective for long sections or when comparing multiple sections. Section records positioned in three dimensions make it clear which section corresponds to which feature and where it sits within the whole survey area, helping fragmented information connect. During report preparation, having three-dimensional information assists in substantiating interpretations of sections.

Explaining stratigraphic sections is often difficult for non-specialist stakeholders. Differences in color and texture, depositional directions, and the meaning of excavation lines are hard to convey with text or plan views alone. Using 3D data allows explanations that show a section’s position and its relationship to surroundings, making it easier to gain understanding in consultations and educational settings.

Sections are a prime example of information that, once destroyed, cannot be restored. Precisely because of this, accurately preserving the moment is crucial. 3D measurement enables thinking of a section not as a single drawing but as an important information plane within space. This raises the reliability and reusability of section records.

Use case 4 Save artifact find contexts with location information

In buried cultural heritage surveys, not only the artifacts themselves but where, at what elevation, and in what condition they were found is important. The find location provides clues as to whether an artifact is close to its primary context, has been displaced, or forms part of a concentration. 3D measurement has great value in recording find contexts with associated location information.

Traditionally, find locations have been managed with plan views, photographs, coordinate records, and notes. These methods remain necessary, but when artifacts are found across multiple layers or when relationships with features are important, planar management alone may not convey enough. Combining 3D measurement allows preservation of the spatial relationships among artifacts, features, and surrounding surfaces, deepening later understanding.

For example, 3D records are very helpful when an assemblage of artifacts is scattered on a floor, when materials are distributed unevenly within fill, or when configurations important to collapse or burial processes need to be considered. Photographs alone can make overlaps and depth hard to interpret, and drawings may omit individual viewpoints; 3D records allow investigation while keeping spatial context intact.

If the pre-recovery state is preserved at high precision, it can be used later during cataloging and analysis. Being able to re-examine pre-removal relationships without relying solely on on-site impressions improves interpretation accuracy. This is particularly effective when significant time elapses between fieldwork and post-excavation processing.

From an education and exhibition perspective, three-dimensional records of find contexts are also valuable. Displaying an artifact on its own can fail to convey context, but showing the three-dimensional situation in which it was found deepens understanding of the excavation results. Thus 3D measurement becomes a recording foundation that places artifacts within the context of buried cultural heritage rather than treating them as isolated objects.

Use case 5 Facilitate analysis of survey results and report writing

The value of 3D measurement extends beyond the moment of on-site recording. In many cases its benefits become most apparent during post-excavation processing and report writing. After fieldwork, practitioners organize large volumes of photographs, drawings, observation records, and survey data, and add interpretations to compile reports. Frequent needs arise to re-check site conditions during that process.

For example, when comparing plans and sections to organize relationships among features, one may want to check the site from a different angle than photographs provide. Or one may want to confirm whether on-site understanding matches the diagrammatic representation of fill boundaries or feature intersections. With 3D measurement data, one can inspect shapes with a sense close to being on site while proceeding with analysis, providing firmer grounds for decisions.

3D records also improve the efficiency of figure creation for reports. Because three-dimensional records make it easy to obtain overview images or arbitrary sections, they can serve as auxiliary materials for drafting figures. Final outputs must of course be organized according to standards, but having underlying three-dimensional information reduces ambiguity in drafting and contributes to consistency checks and clarity of explanation.

They are also effective for handing over work between staff. When the person who excavated and the person who organizes finds are different, subtle on-site nuances may not fully transfer. 3D records allow those who were not present on site to grasp the situation more easily, reducing misalignment in understanding. This is a major advantage for organizationally conducted surveys.

Leaving room for future re-examination is also important. Interpretations of buried cultural heritage do not always solidify immediately after excavation. They may be revisited in later years when new knowledge or comparative materials emerge. If three-dimensional baseline records remain, past sites can be re-read as material for future study. 3D measurement thus not only assists immediate recording tasks but also creates research assets for the future.

Use case 6 Make preservation, utilization, and exhibition/education easier

3D measurement of buried cultural heritage has large potential not only for survey records but also for preservation, utilization, and exhibition/education. While some buried cultural heritage is preserved in situ, much is backfilled after excavation or otherwise not directly accessible to the public. Therefore, how survey results are communicated becomes important. Three-dimensional records obtained by 3D measurement are easy-to-use materials that support that communication.

If the appearance of features at the time of investigation can be reproduced in three dimensions, spatial extent and depth—elements that are not fully conveyed by plans—can be shown more intuitively. Relationships among features, excavation shapes, stone arrangements, and layer stacking can be presented clearly, making general explanations easier to understand. 3D records serve as a bridge to convey value to non-specialists as well as precision records for specialists.

3D records are also convenient materials for local school education and public lectures. Even when people cannot enter the excavation site, one can concretely show what was found and how it was recorded. Conveying the significance of cultural property protection and the process of excavation by demonstrating not only finished exhibits but also the discovery and recording process has great educational value.

From a preservation standpoint, three-dimensional records are important. Faithfully preserving the current condition of features and artifacts increases the potential for future preservation planning, restoration consideration, and comparison during re-excavation. Since it is not possible to preserve everything permanently in situ, high-precision recording of what conditions were like can itself be considered part of preservation.

Furthermore, when aiming for public utilization, it is important not simply to use 3D measurement outputs as-is but to edit them into communicable forms. In practice, it is necessary to separate data intended for precision records from presentation styles for general audiences. The foundation for that is having comprehensive three-dimensional records. 3D measurement is not a technique that ends with the investigation; it can be used as a platform to connect cultural heritage to society.

Principles for making 3D measurement of buried cultural heritage succeed

To make 3D measurement for buried cultural heritage function effectively, merely introducing equipment and methods is insufficient. It is important to operate with a clear view of why measurements are taken, in which situations they will be used, how results will be organized, and who will utilize them.

First, clarifying the recording objectives is essential. Whether you want to preserve the overall condition of the excavation area, capture the detailed shape of a specific feature, document sections for interpretation, or provide auxiliary materials for report figures will determine required precision, capture range, and timing. If objectives remain vague, one may end up collecting data that are difficult to use later.

Next, aligning with the survey workflow is also important. At excavation sites many tasks proceed within limited time—switching working faces, deepening excavations, scrutinizing features, recovering finds, etc. To integrate 3D measurement without overburdening the site, it is necessary to plan in advance which stages are most effective for measurement. Designing whether to capture at each milestone, to focus on important features, or to combine whole-area and individual recordings is indispensable.

Handling positional information is another key point. Even if 3D measurement preserves shapes well, ambiguous relationships with coordinate systems and references make later use difficult. In practice, management of positions—survey area settings, control points, tie points, and consistency with drawings—affects the reliability of results. Having a perspective that ties three-dimensional outcomes to existing record systems increases reusability.

Rules for data organization must not be neglected either. Data that are useful at the time of capture can become hard to find later if naming conventions, storage locations, and links to related records are unclear. Organizing data so that it is clear which time, what range, and which target the data correspond to is a condition for turning on-site success into usable report results and future reuse.

In short, the key to successful 3D measurement of buried cultural heritage lies more in operational design than in measurement itself. Rather than treating it as opposed to traditional records, consider where three-dimensional reinforcement will most improve overall recording capability. Paying attention to the four elements of purpose, workflow, positional information, and organization will significantly change the effectiveness of introduction.

Summary

3D measurement of buried cultural heritage is not merely an advanced recording method but a technique that directly supports fieldwork. Its major practical uses include preserving the overall condition of excavation areas in three dimensions; recording complex shapes and cutting relationships of features in detail; facilitating sharing and re-examination of stratigraphic sections; saving artifact find contexts with location information; aiding post-excavation processing and report writing; and making preservation, utilization, and exhibition/education easier.

In buried cultural heritage surveys, the essence is how to pass on the information seen on site to the future. 3D measurement is a powerful means for that purpose, but what matters is not the adoption of technology itself but designing which information to record, at what timing, and at what precision. When operated in combination with traditional surveyed drawings, photographs, and observation records, it greatly improves the reliability and reusability of records.

Also, to use 3D measurement stably on site, it is essential to manage not only shapes but also positions properly. If excavation area settings, control points, coordinate management of targets, and on-site positional checks are ambiguous, even high-quality results become difficult to use. In such cases, mechanisms that enable easy high-precision position checks on site are helpful. For example, using an iPhone-mounted high-precision GNSS positioning device such as LRTK can streamline coordinate checks around the survey area, control point surveying, and management of recorded positions. If you want to operate 3D measurement for buried cultural heritage more practically, arranging not only three-dimensional records but also ease of on-site position acquisition is a shortcut to improving the quality of outcomes.