Can RTK Be Used for Disaster Response? 5 Use Cases Useful in the Initial Response

Table of Contents

• Why RTK Is Receiving Attention in the Initial Phase of Disaster Response

• Use case 1 Situational awareness immediately after a disaster

• Use Case 2 Sharing locations of road closures and hazardous spots

• Use case 3 Simple surveying for emergency restoration

• Use Case 4 Recording the extent of landslides and flooding

• Use Case 5: Preparing Handover Data for Restoration Work

• Precautions when using RTK in disaster response

• Preparations to Leverage RTK in Initial Response

• Summary

Why RTK Is Gaining Attention in the Initial Response to Disasters

In disaster response, how accurately the situation on the ground can be assessed in the first few hours to days greatly affects the quality of subsequent decisions. Whether roads are passable, how far slopes have collapsed, how widely flooding has spread, and how far emergency repair vehicles can be allowed to enter — all such judgments depend on the accuracy of location information and situational awareness.

A challenge that often arises in this initial phase is that the scene is chaotic and information tends to be fragmented. Damage reports tend to be conveyed verbally or through photos, and it is not uncommon that the exact locations are unclear when reviewed later. Even if you think you have shared a location on a map, if the indicated spot is off by only several dozen meters you may make incorrect judgments about response priorities or equipment deployment.

This is where RTK is effective. RTK is a technique that achieves high-precision positioning by combining satellite positioning with correction information, and a major characteristic is that it makes it easier to confirm positions more precisely than position information from a typical smartphone alone. At disaster sites, rather than immediately conducting rigorous official surveys, it is important first to quickly capture on-site changes and hazardous locations with a certain level of accuracy. In that sense, RTK is very well suited as a tool for recording current conditions, sharing information, and supporting decision-making during initial response.

Of course, you can't complete all disaster response tasks with RTK alone. Its usability varies depending on on-site communication conditions, sky visibility, surrounding terrain, the required accuracy, and the operator's level of experience. Even so, the value of being able to preserve georeferenced data is far greater than relying solely on handwritten notes on paper maps or ambiguous photographic records.

In particular in recent years, on-site devices, apps, and cloud-sharing systems have advanced, making it easier to link RTK-acquired positioning information to photos, point clouds, drawings, and reports. This has made it easier to ensure that information gathered during the initial response does not remain a one-off record, but instead flows through from emergency response to restoration design, construction, and maintenance management.

What is required in a disaster is not to assemble perfect data from the start. Given limited time and personnel, it is to quickly and clearly record information with positional context that can be used for subsequent decisions. RTK is precisely such a tool and demonstrates its strengths in the field during initial response.

Use Case 1: Assessing the Current Situation Immediately After a Disaster

Immediately after a disaster, the top priority is to visualize on-site what is happening as quickly as possible. The types of damage vary—road subsidence, deformation of embankments, scouring of riverbank revetments, bulging of retaining walls, slope failures, and ground displacement around buildings—but they all share the need to quickly establish their locations and extents.

What makes RTK useful in this case is its ability to record representative points and boundary points of damaged locations with high precision. For example, where a step or offset has formed in a road, you can record with positional data the start and end points, the point of greatest deformation, and any narrowed sections of the carriageway that impede traffic. In the case of a landslide, by sequentially recording the head scarp, the leading edge reached by the debris, the flow direction, and the outer perimeter of the deposition area, it becomes easier to organize the current situation on a map.

In the initial stages, people tend to take a large number of photos, but when you look back later it can be unclear where each one was taken. Using RTK lets you clearly link photos to their capture locations, reducing discrepancies in understanding between the person reporting and the person receiving the report. A major advantage is that managers and support departments can more easily grasp the spatial relationships without on-site personnel having to explain them verbally.

Also, when assessing the current situation, even if you cannot immediately calculate the absolute amount of damage, it is meaningful to first identify the locations and extent of the observed deformations. For example, while it is acceptable to calculate the precise area and volume of a slope failure in a later step, simply being able at this stage to indicate the areas where people and vehicles should not approach, the areas that should be monitored, and the areas that require emergency measures will greatly advance initial decision-making.

RTK's strength is that, even when you limit the number of points measured, it can still produce information that is sufficiently useful in practice. In disaster situations, long measurement times and complex operations are difficult, so whether meaningful data can be obtained with minimal actions is crucial. Even simply recording representative points in sequence can clarify the contours of damage and the extent of hazardous areas.

Moreover, the positional data obtained during the initial situation assessment provide a convenient base that can later be overlaid with drone imagery, point cloud measurements, as‑built verification, and emergency recovery design. The fact that data collected during the initial response are not wasted but instead serve as the reference for subsequent steps is of tremendous value in hectic disaster response.

In other words, RTK is a tool for assessing the situation immediately after a disaster that does more than merely record how a site looks; it organizes that information as positional data usable for decision-making. Its value becomes especially clear in situations where people are likely to be uncertain during the initial response.

Use Case 2: Sharing Locations of Road Closures and Hazardous Areas

In disaster response, accurately sharing hazardous locations is as important as assessing the damage itself. If it's unclear where road closures begin, where there is a risk of secondary hazards, or how close heavy equipment and emergency vehicles can approach, both on-site safety and response efficiency suffer significantly.

What makes RTK effective here is that it allows the locations of hazardous spots to be shared not by words but as coordinates or as points on a map. On site, explanations tend to be things like "just past the curve," "before the bridge," or "below that slope," but different recipients may interpret these differently. This is especially true at night, in bad weather, or when support teams from other regions are involved, where descriptions that rely on local knowledge are likely to be misunderstood.

By recording with RTK the road-closure start locations, detour branch points, sediment outflow points, fallen-tree locations, shoulder damage locations, and so on, they can be handled uniformly on maps and shared systems. This makes it easier for personnel who are not on site to understand the situation, and facilitates planning for traffic control, equipment delivery, material staging, and the movement routes of support units.

Also, sharing hazard locations once is not the end. In the immediate aftermath of a disaster, conditions change moment by moment, and a place that was passable in the morning can become dangerous by evening. Conversely, emergency measures can make parts passable. If you use RTK to record time-stamped position data, it becomes easier to document the expansion or contraction of hazardous areas and the movement of cordons. This is also useful for handing over the site.

For example, in shift-based operations, if it is unclear where the previous team judged a location to be dangerous, the next team must recheck everything from scratch. If position-tagged data recorded with RTK is available, it becomes clear which judgment was associated with which location, making handovers significantly easier.

Furthermore, in situations such as briefings for residents and coordination with relevant agencies, clarity of location information is important. When explaining whether evacuation routes are passable, the extent of access restrictions, and priority recovery sections, showing them clearly on a map is easier to understand than using vague expressions. In disaster response, not only field operations but also the responsibility to explain information is significant, so the accuracy of shared location information is an element that cannot be overlooked.

RTK is effective not only as a surveying instrument but also as a tool for improving the accuracy of safety management and information transmission. It plays a major role in reducing the common 'we think we understand' type of communication during disasters and in aligning the understanding among the field, headquarters, support teams, and relevant agencies.

Use case 3: Simple surveying for emergency recovery

In the initial phase of disaster response, decisions on emergency restoration proceed urgently in parallel with assessing the damage. Where to stack sandbags, how to dig temporary drainage channels, which areas to protect with blue tarps or large sandbags, and how much temporary passage width to secure—position and height information are indispensable for emergency response.

In such situations, RTK is very well suited to simple surveying in the initial response phase. Even if it is difficult to reproduce conventional, detailed surveying work exactly during a disaster, RTK can quickly acquire the necessary points on site and make it easier to prepare decision-making materials for emergency recovery. The ability to handle height information in particular is a major advantage.

For example, when part of a road has been scoured, it is necessary to consider how high a temporary fill must be placed to allow passage. In flooded areas, the direction of temporary drainage must be determined while checking the elevation difference to the discharge point. For emergency earth-retaining measures at the base of a slope, it is necessary to understand the installation location and its relationship to the surrounding ground. In such situations, establishing reference points with RTK increases the accuracy of on-site decisions.

Of course, in emergency restoration after a disaster, you are not expected to meet the same level of precision or follow the same procedures as the final restoration from the outset. However, relying solely on intuition and experience makes rework and additional tasks more likely. Temporary restoration work that turns out to be too low in height, to have insufficient drainage direction, or to have incorrect material quantities increases the burden on site.

By establishing the key points in advance with RTK, you can start work with an understanding of the minimum required height and distance relationships, making it easier to reduce failures in temporary measures. As a result, you can more effectively use limited time and materials.

Also, in emergency restoration it is important to document the basis for on-site decisions. If it is recorded in a way that allows later verification of why a temporary repair was carried out at that location, why fill was placed to that height, and why sandbags were positioned there, it will inform subsequent actions. RTK data has the advantage of being easy to use as part of that basis.

At initial response sites, speed tends to take top priority, but speed alone is not sufficient. If you move quickly but in the wrong direction, it can lead to rework and safety risks. Simple surveying using RTK is an effective means to make on-site decisions more reliable and to raise the quality of emergency restoration.

Use Case 4: Recording Landslide and Flood Extents

In disaster response, accurately recording the extent of damage is extremely important. Whether it is possible to record at an early stage how far landslides have spread, how far flooding has reached, and which sections of riverbank protection have collapsed determines subsequent damage assessment, recovery policy, budget requests, and the ease of explaining the situation to residents.

The reason RTK is well suited to this kind of area recording is that it makes it easy to capture the perimeter and representative lines with positional information. In the case of a landslide, you can grasp the approximate outline by connecting multiple points at the upper, side, and lower edges of the failure area. For flooding, sequentially acquiring representative points of water marks or the inundation boundary makes it easier to improve the reproducibility of the inundation extent.

During the initial phase, it can be difficult to fully cover the extent of damage. There are various constraints, such as water that has not yet receded, the risk of secondary collapse, limited access routes, and poor visibility at night. Even so, recording representative points within the range you can access is very important. These points serve as reference markers when later overlaying photos or aerial images, which increases the reliability of the damage records.

Recording the extent of damage is not simply about creating reports. For example, understanding the area affected by debris flow helps identify zones that should be put on alert for future rainfall. Capturing the height and location of flood marks can inform reviews of drainage functions and the placement of temporary pumps. In other words, damage records directly serve as input data for subsequent countermeasures.

Also, information after a disaster is lost over time. Water level marks disappear with cleaning or drying, sediment deposits are removed, and pavement deformations become invisible after temporary repairs. Even if you plan to measure again once the site has stabilized, the initial state is often no longer present. Therefore, how much location-tagged documentation you can record during the initial response is extremely important.

RTK-based records become even more valuable when combined with subsequent aerial photographs and point cloud measurements. Having control points established on-site makes it easier to align images and point clouds, verify extents, and compare results. At disaster sites, rather than trying to cover everything with a single measurement method, what matters is securing reference points that link multiple methods, and RTK is well suited to play that role.

Recording the extent may seem like a mundane task, but it is an important job that affects the quality of the initial response. As a first step in quantitatively assessing the scale of damage, RTK is a highly practical method.

Use Case 5: Creating Handover Data for Restoration Work

In disaster response, whether the information collected by the initial response team can be used directly for restoration work greatly affects the speed of subsequent processes. Even if a lot of information is gathered on site, if locations are ambiguous or recording formats are inconsistent, designers and construction personnel will have to repeatedly conduct on-site checks. This is a significant loss of both time and manpower.

The advantage of RTK is that it makes it easy to pass information collected in the initial response phase directly on to subsequent stages. If representative points of damaged areas, hazardous zones, passable areas, locations for temporary structures, edges of scour or collapse, and so on are recorded with coordinates, they can be readily used as initial data for restoration design and construction planning.

Especially in restoration work, a major advantage is the ability to reduce the number of on-site surveys. Disaster sites often have access restrictions, and not all stakeholders can enter the site repeatedly. If the location data and photographs collected during the initial response are well organized, designers can more easily carry out desk-based planning, and construction teams can more easily improve the accuracy of their preparations.

Also, an important part of handover is keeping a chronological record of changes at the site. The condition immediately after the disaster, the condition after emergency restoration, and the condition before starting full restoration are each different. If you record the position information at each point in time with RTK, it becomes easier to explain what changed at which stage. This is also useful for decisions about design changes or additional measures.

A common challenge in the initial response is that there is too much information that only on-site personnel know. Even if it is understood in their heads, information is lost when there are personnel transfers, replacements, or changes in support arrangements. Data acquired with RTK is easier to hand over without relying on individual memory, so it helps reduce the person-dependence of responses.

Furthermore, it provides material for post-disaster reporting and review that can explain what judgments were made during the initial response. If data remain showing which locations were deemed dangerous, where emergency restoration began, and which areas were prioritized for response, the decision-making process will be easier to follow afterward. This is also important for enhancing the organization’s disaster response capability.

RTK is not just a tool to assist on-site work. It is also highly effective as a bridge that smoothly links the data collected during the initial response to recovery work. When disaster response is viewed not as isolated points but as a continuous flow, its value becomes even greater.

Precautions when using RTK for disaster response

RTK is an effective tool for disaster response, but if used incorrectly it may not deliver the expected results. To make it truly useful in initial response, it is necessary to understand not only its strengths but also its limitations.

The first thing to note is the dependence on the communication environment. When using network-based correction information, if mobile communications become unstable due to a disaster, reception of the correction data can be easily interrupted. As a result, positioning stability may deteriorate and work itself may be halted. Because the likelihood of communication failures is higher in disasters than in normal times, it is important not to rely solely on operations that assume continuous communications.

Next, there is the issue of sky visibility. Satellite reception conditions tend to deteriorate at collapse sites in mountainous areas, in places surrounded by trees, under overpasses, and next to buildings. At disaster sites, the influence of terrain and structures is large, and there are often situations where positioning conditions are more severe than during normal times. In locations where measurements cannot be obtained, do not blindly trust the results; use them while checking the positioning status.

Also, because speed is prioritized in the initial response, workers may omit confirming settings. However, if the coordinate system, the way heights are handled, the recording format, and the method for establishing references are not standardized, confusion will arise when using the data later. For example, if records are made with different settings at each site, it becomes difficult to consolidate the data during recovery operations. During disasters, it is particularly important to clearly define the minimum required setting rules.

Furthermore, safety must not be overlooked. If you focus too much on taking measurements with RTK equipment, it becomes harder to notice dangers such as ground collapse beneath your feet, falling rocks, rising water at the shoreline, or secondary collapses. At a disaster site, being able to withdraw safely takes priority over being able to measure. Avoid forcing measurements in hazardous areas, and, when necessary, make decisions such as capturing representative points from a distance or combining measurements with alternative methods.

Power management is also important. During disasters, responses tend to be continuous for long periods, and charging facilities may be insufficient. If any device—terminal, receiver, or communication equipment—runs out of battery first, the entire operation will come to a halt. Backup power is more critical than during normal operations, and battery performance degradation due to heat or cold must also be taken into account.

RTK's high precision doesn't make it a panacea. What disaster response truly requires is on-site usable accuracy and the ability to preserve it in a form that helps with subsequent decision-making. Therefore, rather than chasing perfection, it's important to determine where and how to use it based on field conditions.

Preparations to Utilize RTK in Initial Response

It's too late to try to learn how to use RTK in a panic after a disaster strikes. The quality of initial response varies greatly depending on what preparations are made during normal times.

The first thing required is to narrow down the use cases. Even if you introduce RTK for disaster response, assuming you will measure everything makes operations complicated. It is important to first clarify the situations in which it will actually be used during the initial response, such as recording the locations of damage, sharing hazardous zones, simple surveying for emergency restoration, and recording the outer perimeter of the damaged area. If the use cases are narrowed, the necessary settings and recording formats can also be simplified.

Second, the standardization of recording rules is necessary. If it has not been decided which points to record, how photos should be linked, how names should be assigned, or in what format information should be shared, valuable location data will be difficult to utilize. Because workers will be split into multiple teams during the initial response, it is important to have at least the minimum rules in place in peacetime.

Third, you should plan alternatives for communications and power. In a disaster, prepare on the assumption that normal infrastructure may be unavailable. Organizing in advance spare batteries, charging methods, ways to secure correction information, and procedures for working when communications are unstable will reduce confusion in the field.

Fourth, it is important to configure equipment so it is easy to handle on-site. In the initial response to a disaster, heavier and more complex equipment tends to be used less. A setup that can be brought online quickly, is easy to carry, and makes it easy for multiple people to share how to operate it is desirable. If you prioritize field operability, configurations that emphasize portability and ease of use—such as LRTK, an iPhone-mounted GNSS high-precision positioning device—are also practical in real operations. In an emergency, not only performance but also how confidently and to what extent anyone can use the equipment without hesitation is critically important.

Fifth, it is essential to use them during training. Equipment that is useful for disaster response becomes difficult to employ in a real event unless it is actually handled during routine inspections and drills. If you repeatedly practice tasks such as recording the locations of hazardous areas, checking temporary access routes, and creating photo-attached report data according to assumed damage scenarios, your response time when a disaster occurs will be faster.

To leverage RTK in disaster response, advanced surveying knowledge is not the only thing required. Rather, it is important to simplify how it is used to match initial on-site actions and to embed that into operations that directly support decision-making and information sharing. Just a little preparation in peacetime can greatly improve its usability when an incident occurs.

Summary

RTK is a technology that can be sufficiently used in the initial response to disasters. In particular, in five situations—assessing current conditions immediately after a disaster, sharing the locations of road closures and hazardous spots, simple surveying for emergency restoration, recording the extent of landslides and inundation, and creating handover data for restoration work—the practical effects are clearly evident.

What is truly needed in a disaster is not to take time producing perfect results, but to quickly, accurately, and in an easily shareable form record information that can be used for the next decision. RTK is a means that meets that need and provides the positional clarity that photos or verbal reports alone often lack.

On the other hand, because there are issues such as communication environments, satellite reception conditions, safety management, securing power supplies, and standardizing settings, simply possessing the equipment does not necessarily make it useful. It is important to clarify the intended use during peacetime and establish operations that prevent confusion on site.

In disaster response, the first few hours can determine what follows. Within that limited time, RTK holds great potential as a tool to visualize damage, share hazards, and connect to emergency response and recovery. If prepared in a form usable on-site, it becomes a practical weapon that supports fast and reliable decision-making when the time comes.