7 Common Problems in Drone Surveying and Countermeasures

Table of Contents

• Why Drone Surveying Is Prone to Problems

• Trouble 1: Unable to access the site due to insufficient pre-flight checks

• Trouble 2 Misjudging the weather leads to reshooting

• Problem 3: Insufficient design of calibration and reference points results in poor accuracy

• Issue 4: An inadequate flight plan results in missing data

• Trouble 5 Point clouds and images become distorted due to on-site conditions

• Issue 6: Delivery halted due to a discrepancy between the coordinate system and the deliverable specifications

• Problem 7 Work stalls due to insufficient preparation for data processing and storage

• The mindset operational staff should adopt to reduce problems

• Summary

Reasons Why Drone Surveying Is Prone to Problems

Drone surveying is a convenient method that makes it easy to capture large areas in a short time and to acquire current conditions without putting people into hazardous locations.

On the other hand, in practical work many more conditions are involved than you might expect. Flight feasibility, the surrounding environment, imaging conditions, how control points are established, the handling of coordinates, the processing environment, specifications of deliverables, and so on—if even one of these is overlooked, it can cause cascading problems from fieldwork through post-processing.

Especially for staff introducing drone surveying for the first time, or sites that have begun using it partially as a supplement to conventional surveying, it is often perceived that "if you fly it, you'll get results immediately." However, in reality the flight itself is only one part of the entire process. If pre‑flight planning is inadequate, the flight on the day may be canceled, and even if the flight goes well, insufficient accuracy or data loss discovered during post‑processing will require re‑shooting or re‑calculation. In other words, many problems arise not just from the pilot's skill but from the procedural design of the survey.

Also, the difficulty of drone surveying varies depending on the target. The same flight method that works on open, easy-to-survey sites such as graded development sites does not apply to areas with many trees, terrain with continuous slopes, locations where structures are densely clustered, or sites that include water surfaces. You must change your plan according to site conditions, and if you neglect to do so you may end up with data you thought you’d captured but that cannot be used later.

This article organizes seven common issues that often arise in drone surveying and clearly explains the causes of each and practical measures to address them. It is compiled to be useful to those responsible for choosing an external contractor, those advancing in-house implementation, and those considering operating drones in-house.

Trouble 1 Unable to Enter the Site Due to Insufficient Pre-flight Checks

The most common early problem in drone surveying is discovering upon arrival at the site that "we can't fly today." This is caused more by insufficient pre-flight checks than by technical issues. If airspace conditions over the survey area, relationships with nearby facilities, third-party access, restrictions on working hours, and the communication system with the site supervisor are not properly organized, you cannot begin work even after preparing and arriving on site.

In practice, whether a flight is permitted is not determined by a single requirement. Even if there are no problems with legal checks, the site manager may not have approved flights at that time, coordination with nearby residents may not be complete, or vehicles from other trades may be coming and going frequently, making it difficult to ensure safety. Especially at construction sites, the day-to-day work changes, so even if there were no issues the previous day, the situation on the day itself may have changed.

What makes this problem particularly troublesome is that it only becomes apparent once personnel and equipment are assembled. As a result, the entire day's work is pushed back, affecting the next stage. If the work is outsourced, the schedule must be rearranged; even with in-house operations, personnel must be reassigned and other projects are impacted. From the site’s perspective, if the reason the flight couldn't take place is judged to be "insufficient checks," confidence in the survey plan itself is likely to erode.

An important part of mitigation is not to judge whether a flight can proceed solely by whether permission has been granted. You need to confirm, at the operational level on the day, the site manager, the client-side contact, whether there will be any impact on neighboring areas, third-party movement routes, the work time window, the area of restricted access, the takeoff and landing locations, and how safety will be ensured. Even if the paperwork is in order, it is meaningless unless the assumptions for on-site operations have been firmly established.

Furthermore, do not treat the flight go/no-go check as a one-time action; assuming a morning recheck on the day of the flight reduces the likelihood of problems. This is because not only weather but also changes to site schedules and the addition of nearby work can occur at the last minute. Drone surveying’s strength is its on-site mobility, but to leverage that mobility it is important to standardize pre-flight checklist items so that any person responsible can verify them to the same standard.

Trouble 2 Misjudging the weather leads to reshooting

In drone surveying, many people understand that rainy or very windy days are dangerous. However, in reality, "whether a flight can take place" and "whether survey quality can be ensured" are separate issues. Even if flight itself is possible, it is not uncommon for the acquired data to be insufficient and require re-shooting. This is what makes weather judgment difficult.

A typical example is the effect of wind. When the wind is strong, the aircraft’s attitude becomes less stable, causing subtle variations in the shooting position and orientation. Even if it appears to be flying normally, image overlap can become unstable and diagonal blur can increase, which leads to reduced accuracy during post-processing. The wind’s impact on model quality is especially pronounced in areas with large terrain changes or many vertical structures.

Don't let your guard down during overcast or dim conditions. When light is insufficient, shutter conditions become unfavorable, causing images to become soft and making it harder to capture fine details. Conversely, even on clear days, depending on the sun's altitude and how shadows fall, slopes and the sides of structures can become extremely difficult to see. Shooting from directly overhead is especially susceptible to shadow effects, and the stability of processing results at the same site may vary by time of day.

Additionally, caution is needed for ground surfaces after rain or in damp conditions. Mud, puddles, wet pavement, and highly reflective surfaces can negatively affect image processing and point cloud generation. Areas near water surfaces or mirror-like surfaces are especially likely to produce unstable shapes, introducing errors into current-condition assessments. Even if they appear fine visually, they can impact the quality of deliverables, so simply checking weather information is not sufficient.

As a precaution, it is important to make flight decisions not only based on wind speed and whether it is raining, but also by including lighting and ground-surface conditions that are unfavorable for the subject. Acceptable conditions vary depending on whether the surveying objective is as-built verification, earthwork volume estimation, or acquisition of base data for mapping. Decide the minimum quality required for the objective in advance, and make the decision not to fly on days when that quality is unlikely to be met.

In practice, it is effective to secure alternative dates as candidate days from the outset. Although drone surveying often gives the impression that it can be completed in one day, in reality schedule design that incorporates weather risks is necessary. Scheduling without buffer days leads to pressured flight decisions and, as a result, increases the likelihood of re-shooting. To maintain survey quality, it is important to base decisions not on whether a flight is possible, but on whether it can be flown under good conditions.

Issue 3 Poor accuracy due to insufficient design of control points and reference points

A major factor that determines the reliability of drone surveying results is the design of ground control points and reference points. If this is left unclear and you proceed, you may produce visually pleasing 3D models and orthophotos but find that the actual coordinate accuracy is insufficient. This problem can occur not only for beginners but also on sites with experienced teams.

Common problems include an insufficient number of control points, uneven placement, poor visibility, and lack of standardization in coordinate acquisition methods. If points are concentrated only near the center of the site, accuracy tends to degrade at the edges and in areas with large elevation differences. Also, on slopes or long, narrow construction areas, even if you think you have arranged points evenly in plan, in reality there may be insufficient constraint in the vertical direction.

What makes matters worse is becoming complacent after merely installing control points. If control points are not sufficiently visible in the images, blend into the background and are hard to identify, or fall into shadow and are difficult to detect, they become difficult to use in post-processing. Even if the coordinates themselves are correct, if they cannot be clearly read on the images, the effectiveness of accuracy control is reduced. Visibility in the field and visibility in aerial images are not the same.

Also, if the reference coordinate system and elevation datum are not consistent across the site, this can cause accuracy problems. Even if horizontal positions appear correct, a shift in the elevation reference can create major issues for earthwork quantity calculations and as-built evaluations. When the client, contractor, and surveyor have differing understandings of the reference standards, adjustments later on become difficult.

As a countermeasure, it's important to design control points not only in terms of "how many to place" but also "where, for what purpose, and how to present them." You need to consider placement including planar extent, edge restraints, accommodation of elevation differences, and ease of re-checking. In particular, on long, narrow sites, sites with many steps or level changes, or sites with many structures, a simple equally spaced arrangement tends to be insufficient.

Additionally, before entering the site, it is useful to confirm the required accuracy of the deliverables and work backward to determine how elaborate a control-point design is necessary to achieve that accuracy. Rather than placing control points haphazardly, designing them according to the intended use of the deliverables enables preparation that is neither excessive nor insufficient. Keep in mind that the accuracy of drone surveying is not determined solely by the aircraft’s performance, but can vary greatly depending on the quality of the survey design.

Trouble 4: Inadequate flight planning leads to missing data

Flight planning for drone surveying is not simply the task of creating an automated flight route. It is the process of deciding at what altitude, from which directions, how much overlap to include, and which parts of the target to reliably capture. If this planning is inadequate, even if the flight has been completed on site, data gaps or insufficient quality may be discovered later.

A typical problem is an insufficient overlap rate. If images do not overlap sufficiently, the ties during processing become weak, causing parts of the model to fail to be generated or to become locally distorted. Even if the issue is hardly noticeable on flat ground, insufficient overlap quickly becomes apparent on slopes, retaining walls, around buildings, excavation areas, and terrain with large relief. Even if it looks like you saved on the number of flights, it is meaningless if re-shooting becomes necessary.

Also, attempting to rely solely on imagery taken directly overhead can result in insufficient side information. For land development sites and plan-view purposes, overhead photography as the primary approach is acceptable, but for wall surfaces, embankments, three-dimensional structures, and areas with pronounced level changes, overhead-only imagery cannot adequately reproduce the shapes. If you create flight plans based on a two-dimensional assumption when handling three-dimensional forms, the reliability of the site model will decrease.

Mistakes in setting flight altitude are also common. If the altitude is too high, ground resolution decreases and it becomes difficult to discern fine details. If it is too low, the number of flights and photos increases, processing load rises, and you may not be able to cover the entire area in a short time. In other words, it’s not simply that higher is easier and lower is more precise; a balanced design tailored to the subject and the objective is necessary.

Additionally, flying uniformly at a constant altitude without accounting for variations in terrain and obstacles is also dangerous. On sites where the distance to the ground varies greatly from place to place, imaging conditions can change dramatically in only some areas, making image quality and resolution uneven. This tends to cause processing results to be partially degraded, resulting in a mix of usable and unusable areas within the same site.

As a countermeasure, define the deliverables concretely first and design the flight plan based on how those deliverables need to look. The required capture method changes depending on whether the primary objective is orthophotos, whether point clouds are needed, whether it will be used to check cross-sections, or for as-built comparison. At some sites, it is more reliable to treat planar mapping and three-dimensional capture as separate flights rather than a single flight.

Additionally, implementing a practice of performing a quick on-site check immediately after finishing the capture is effective. Even if you can’t complete the full processing, simply confirming whether areas prone to data loss were captured, whether control points are sufficiently visible, and whether there are any unexpected shadows or motion blur can significantly reduce the risk of needing to revisit. A flight plan should not be considered complete once it has been created in advance; it should be regarded as finalized only after being checked on site.

Trouble 5: Point Clouds and Images Distorted by Site Conditions

In drone surveying, there are targets that are difficult to capture depending on site conditions. Typical examples are trees, grassland, water surfaces, uniform paved surfaces, highly reflective surfaces, thin structures, and areas with strong shadows. These targets tend to make image and point cloud generation unstable, and surveyors may not obtain the accuracy and repeatability they expected.

For example, grasses and trees often sway slightly even in light winds, so their appearance changes from one capture to the next. As a result, surfaces can look blurred and point clouds can gain thickness, making it difficult to read the position of the ground surface. When calculating soil volumes or comparing conditions before and after earthworks, acquiring data without considering how to handle the effects of vegetation makes the assessment of the current condition itself unstable.

Water surfaces are also challenging subjects. Even when they appear flat, reflections and transmission can make it difficult to extract feature points, and their shape may be unstable in image processing. Areas affected by moisture—ponds, retention ponds, puddles, and wet ground—tend to have indistinct boundaries with the surrounding terrain, which can lead to misinterpretation when evaluating cross-sections or areas.

In areas where structures are densely clustered, shadows and occlusion become problematic. Places along walls, under eaves, beneath bridges, and around equipment are hard to see from above, and imaging that focuses on straight-down (nadir) shots tends to be lacking in information. Thin elements such as railings, pipes, and power lines are inherently difficult to reproduce reliably, and may be missing or represented as different shapes in the final deliverables. This is not easy to avoid through equipment performance alone; it stems from the nature of the objects themselves.

Homogeneous pavement and otherwise monotonous surfaces can be an unexpected pitfall. On surfaces with few patterns and limited features, correspondence between images can become weak. For large parking lots or featureless roof surfaces, processing can be more difficult than it appears, so designing flight conditions and auxiliary information is necessary.

An important countermeasure is to articulate, before flight, what this site struggles with. If there is a lot of vegetation, understand the limits of surface mapping and, if necessary, consider using alternative methods. If there is a water surface, evaluate the shoreline accuracy carefully. If there are many structures, do not rely solely on overhead (nadir) imaging; plan in advance for oblique/side-view information and methods to supplement it.

In short, drone surveying is not a panacea. Operating without knowing which targets it struggles with leads to problems. Conversely, if you identify those unfavorable conditions in advance, you can adjust objectives, change imaging methods, or add auxiliary measures to achieve realistic deliverables. What practitioners need is an attitude of not overestimating what can be done.

Trouble 6: Delivery stops due to discrepancy between coordinate system and deliverable specifications

In drone surveying, an often-overlooked issue is mismatches in coordinate systems and deliverable specifications. Even when flights and processing are finished on site, it can become apparent just before delivery that "these coordinates can't be used," "the height reference is different," or "the format doesn't match," causing work to stop. This is a typical example of a problem caused more by a lack of shared assumptions among stakeholders than by technical shortcomings.

In particular, the deliverables required vary depending on whether the client needs background material for plan drawings, point clouds for 3D comparison, or models for construction quality control. In some cases images alone are sufficient, while in others a point cloud with coordinates or a format usable for cross-section checks is necessary. If you proceed with “a complete set of drone survey data” without clarifying the intended use, differences in understanding will surface later.

Vertical reference is also an area prone to problems. Even if horizontal positions appear to overlap without issue, if the vertical reference differs, earthwork volumes and as-built comparisons will not align. It is not uncommon for the reference that was taken for granted on site to be inconsistent with the client's workflow. If you attempt conversions or corrections afterward, it becomes hard to tell which values are the originals, making it difficult to explain the quality.

File format mismatches are also common. The required formats vary depending on the recipient’s environment, such as point clouds, images, and data for drawing coordination. Even if the creator prepares files in a format that is easy for them to handle, the workflow fails if the recipient cannot open them as-is. As a result, conversion work and re-exporting are added, putting pressure on delivery schedules. You should consider delivery not as handing over data, but as handing it over in a state the recipient can use.

The countermeasure is to clearly document before flight “what, at which coordinates, in what format, and for what purpose.” If this remains vague and you proceed, operations may appear to go smoothly on site but will stall at the end. Especially when outsourcing, you should verify that the estimate and the delivered contents match, and confirm not only the deliverable names but also the actual usage scenarios.

Even for in-house operations, field staff, design staff, construction management staff, and client liaison staff may each have different expectations. By clarifying who will use what and establishing a shared understanding, you can avoid unnecessary rework. The value of drone surveying lies not in capturing data, but in converting it into usable deliverables. In that sense, sharing the coordinate system and deliverable specifications is as important as the flight plan.

Trouble 7: Work stalls due to insufficient preparation for data processing and storage

Drone surveying is only half complete when on-site data capture is finished. In practice, a large proportion of the work is taken up by subsequent data organization, backup, processing, verification, and producing final deliverables. If you underestimate this phase, post-flight work will become congested and you will not be able to fully realize the value of the data acquired on site.

A common issue is that the number of images captured and the volume of data exceed expectations, resulting in insufficient storage, lengthy transfer times, and excessive load on processing workstations that prevents progress. Especially with high-resolution images or wide-area data, post-processing can take longer than the fieldwork itself. When a single person handles everything from flight to processing and delivery, this is liable to become a bottleneck.

Disorderly file management is also a major cause of trouble. If the capture date, site name, coverage area, coordinate information, and information on the reference points used are not organized, you cannot trace them when reprocessing or rechecking is required later. In the worst case, you can lose track of which data is the final version, making it difficult to explain to stakeholders. This is not a technical problem but a deficiency in operational rules.

Also, if you omit verifying the processing results, you may fail to notice missing data or poor accuracy, which can become problems in later stages. If defects are found after on-site work has progressed, re-shooting may become difficult. By performing a quick check immediately after shooting, a quality check after processing, and a usability check before delivery, you can stop issues at an early stage.

As a countermeasure, it is necessary to decide on a data management plan before shooting. Deciding in advance where to store data, who will organize it, which naming conventions to use, when to back it up, and what to check after processing can reduce confusion caused by individual practices. In drone surveying, operational procedures for organizing data after capture are more directly linked to continuity than piloting skills.

Furthermore, as the number of sites increases, standardizing post-processing becomes increasingly important. If the way data is organized differs between projects, reusing or comparing past projects becomes difficult. For operational staff, the quickest way to prevent problems is to consider, when implementing, not only the selection of aircraft and software but also whether the data flow can be standardized.

Key Concepts Practitioners Should Grasp to Reduce Problems

There is a common thread among the seven issues we’ve examined so far: many of the problems stem not from piloting mistakes on the day, but from insufficient advance planning and information sharing. Because drone surveying makes the on-site flying operation conspicuous, attention tends to focus on piloting skills, but for stable operation in practice, pre-flight and post-flight management are more important.

First and foremost, it is important to plan by working backwards from the objective. For verifying current conditions, calculating earthwork volumes, creating drawings, or comparing as-built results, the required level of accuracy and the capture method will vary depending on the objective. If you proceed while the intended use is unclear, flight conditions and deliverable specifications tend to become half-baked, which can in turn become a breeding ground for trouble. Simply clarifying in advance what you want to obtain will change the quality of the necessary preparations.

Next, do not treat site conditions in general terms. Even with the same drone surveying, the level of difficulty differs between an open developed site and a tree‑covered slope. For each site, identify the conditions that pose problems, avoid unrealistic expectations, and be prepared to consider auxiliary measures when necessary. Overconfidence makes failure more likely; drone surveying is more stable when its limitations are understood and respected.

Furthermore, it is important not to forget the perspective of the people who will use the deliverables. Depending on who uses them—clients, construction managers, designers, or other departments within the company—the required data will vary. If format and presentation are decided solely for the convenience of the data collectors, the delivered data may end up unused. The value of surveying is determined not by the quantity collected but by whether it can be used for decision-making.

Moreover, whether operated in-house or outsourced, it is useful to develop checklists. If you standardize pre-flight checks, ground control point design, weather assessment, post-capture checks, post-processing checks, and pre-delivery checks, quality is more likely to remain stable even when personnel change. Troubles cannot be eliminated entirely, but you can reduce their likelihood and minimize their impact if they do occur.

Summary

As common problems in drone surveying, seven issues were explained: insufficient pre-flight checks, errors in weather assessment, inadequate design of ground control points and reference points, weak flight planning, data disturbances caused by site conditions, mismatches in coordinate systems and deliverable specifications, and insufficient preparation for data processing and storage. None of these are rare failures; they are issues that tend to recur in practical work.

The important point is that many issues only surface after the flight. Therefore, if you become complacent once the flight is over, rework is likely to occur in later stages. To stably incorporate drone surveying into business operations, process design that includes both pre- and post-flight steps is essential. You need a perspective that manages not only capture techniques but also verification, sharing, organization, and delivery as a single, continuous workflow.

Also, to successfully introduce drone surveying, it is important to consider how the data collected on-site will be connected to subsequent positioning, as-built verification, stakeout/setting-out, and sharing with stakeholders. Rather than simply stopping at aerial imaging, if you can turn the data into coordinate information usable on-site, the value of surveying will expand greatly.

In that respect, combining drone surveying with a system that enables easy, high‑precision position checks on site expands the range of ways the acquired data can be used. LRTK is one option as an iPhone‑mounted GNSS high‑precision positioning device that makes on‑site position checks and simple surveying easier to carry out. If you want to connect the current-condition data acquired by drone to field operations, considering adoption not only for aerial acquisition but also for the ease of high‑precision handling on the ground will lead to fewer operational problems.