Drone creating a point cloud using slam lidar

Drone Photogrammetry, Lidar & Hybrid Aerial Surveying compared

Aerial surveying has come a long way, with technological advancements enabling more accurate and efficient data collection than ever before. In this blog post, we will help you navigate the world of aerial surveying by discussing “drone photogrammetry vs lithium or hybrid surveys” and comparing these two cutting-edge methods that have revolutionized the industry, as well as the benefits of hybrid surveys that combine the best of both worlds.

We will explore their key differences, advantages, and disadvantages to provide you with a comprehensive understanding of their applications in various sectors. By the end of this blog post, you will be better equipped to make an informed decision on which method is best suited for your specific project needs, considering drone photogrammetry vs. Lidar or hybrid surveys.

Short Summary

Drone Photogrammetry vs Lidar: Key Differences

Aerial view of a landscape with a lidar system

Aerial view of a landscape with a lidar system

Drone photogrammetry and Lidar are distinct technologies, each with its own unique strengths and weaknesses. Drone photogrammetry utilizes high-resolution images to acquire data for 3D mapping, whereas laser uses laser pulses for the same purpose. This fundamental difference in data capture methods leads to contrasting outcomes in terms of photorealistic. Photogrammetry produces photorealistic mapping results, such as orthomosaics, point clouds, and textured mesh, while lithium yields a sparse laser point cloud that provides an overall understanding of shapes and contours but lacks contextual detail.

Both photogrammetry and laser offer high accuracy, but their respective strengths vary depending on the application. Photogrammetry is more user-friendly, cost-effective, and flexible in terms of where, when, and how data can be captured. However, it requires camera calibration for environmental conditions. In contrast, Lidar excels in providing greater detail and accuracy in missions performed in low light or at night but comes with a more challenging hardware setup and higher cost.

Data Capture Methods

Drone photogrammetry and Lidar differ significantly in their approach to data capture. Photogrammetry relies on high-resolution images taken by drones to generate 2D maps or 3D models, which are easily recognizable and comprehensible. Lidar, on the other hand, uses laser pulses to create a point cloud that represents the surface of the earth or an object with high accuracy. Although lithium point clouds may not be as visually appealing as photogrammetry data, they offer a higher level of detail and accuracy for certain applications. By combining both methods, a photogrammetry point cloud can be generated, providing the best of both worlds.

The accuracy of drone photogrammetry depends on various factors, including the quality of the drone and its inertial measurement unit, camera, sensor size, resolution, focal length, and ground sample distance (GSD). The GSD has an inverse relationship with accuracy, meaning that as it decreases, the accuracy increases. In contrast, the accuracy of the laser depends on factors such as sensor quality and flight altitude.

Ultimately, both photogrammetry and lithium have their advantages when it comes to applications requiring high absolute accuracy.

Accuracy and Precision

Accuracy and precision are critical factors in determining the suitability of photogrammetry and Lidar for specific applications. Photogrammetry offers high accuracy in areas free from dense forest canopy, making it ideal for construction, city planning, and marketing applications. However, photogrammetry struggles in dense vegetation and requires good lighting conditions for accurate results.

On the other hand, lithium excels in mapping dense vegetation and power lines, providing precise elevation data. This makes lithium a popular choice for forestry and power line mapping applications. While both photogrammetry and Lidar can provide high accuracy, Lidar is generally more precise, especially in dense vegetation. This increased precision comes at a higher cost and greater complexity compared to photogrammetry.

Applications

Selecting the appropriate technology for a project depends on the specific requirements of that project. Photogrammetry is well-suited for construction, city planning, and marketing applications, where high-resolution images and accurate 3D mapping are essential. In these cases, the user-friendliness and affordability of photogrammetry make it a popular choice.

Conversely, lithium is particularly advantageous for forestry and power line mapping, which require accurate elevation data in dense vegetation. With its ability to penetrate dense vegetation and provide precise measurements, lithium is the go-to technology for these specialized applications. However, the higher costs and complexity of the Lidar systems may be limiting factors for some projects.

Advantages and Disadvantages of Drone Photogrammetry

Aerial view of a drone surveying a landscape

Aerial view of a drone surveying a landscape

Drone photogrammetry offers several advantages over traditional land-based surveying methods. Its user-friendliness, cost-effectiveness, and flexibility make it an attractive option for a wide range of applications. By capturing high-resolution images from multiple vantage points, drone photogrammetry can generate accurate 2D maps and 3D models with relative ease. Furthermore, drones can access hard-to-reach or hazardous areas, reducing the risk to surveying crews and providing more comprehensive data.

However, drone photogrammetry has its limitations. It can struggle in areas with dense vegetation, and optimal results are achieved in well-lit environments. Additionally, the accuracy of photogrammetry depends on various factors, such as the quality of the drone and camera, sensor size, resolution, focal length, and ground sample distance (GSD). In these situations, a digital terrain model can provide valuable insights.

Despite these limitations, drone photogrammetry remains a popular choice for many projects due to its versatility, affordability, and ease of use.

Affordability

One of the primary advantages of drone photogrammetry is its affordability compared to Lidar. The equipment and processing costs associated with photogrammetry are significantly lower than those of Lidar systems. This makes drone photogrammetry an attractive option for projects with limited budgets or those requiring frequent data updates.

Moreover, the financial risk associated with deploying a more affordable photogrammetry drone is substantially lower compared to a high-cost Lidar drone. In the event of a damaged or crashed drone, the expense of replacing a photogrammetry drone is less prohibitive than the full cost of replacing a Lidar drone.

User-friendliness

Drone photogrammetry is renowned for its user-friendliness, requiring minimal effort apart from operating the drone and taking pictures. No specialized knowledge or training is necessary to effectively employ drone photogrammetry, making it accessible to a wider range of users.

Dedicated support teams are available to assist users with drone photogrammetry, including setup, operation, and data analysis within a coordinate system. Additionally, optimized workflows can be utilized to facilitate the capture and analysis of data, such as automated flight planning, automated data processing, and automated data analysis.

This ease of use, combined with the affordability of drone photogrammetry, makes it an attractive option for a variety of applications.

Limitations

While drone photogrammetry offers numerous advantages, it is important to recognize its limitations. Photogrammetry struggles in areas with dense vegetation, as the overlapping images captured by the drone can be difficult to process accurately. In such cases, lithium may be a better choice due to its ability to penetrate dense vegetation and provide accurate elevation data.

Additionally, photogrammetry requires good lighting conditions to yield accurate results, making it less suitable for low-light or nighttime applications. In these instances, light detection technology such as Lidar’s active sensor, like a lidar sensor, provides an advantage, as it does not rely on external light sources.

Despite these limitations, drone photogrammetry remains a popular and versatile choice for many projects.

Advantages and Disadvantages of Lidar

Drone Lidar on a planning application site revealing the hidden detail underneath the tree canopy. Land surveying with a drone is far quicker than a traditional survey

Drone Lidar on a planning application site revealing the hidden detail underneath the tree canopy. Land surveying with a drone is far quicker than a traditional survey

Lidar offers numerous benefits, particularly in terms of accuracy and precision. Its ability to capture detailed 3D data with high accuracy makes it an ideal choice for specialized applications such as forestry and power line mapping. Lidar is also capable of capturing data quickly, allowing for rapid data collection with high precision.

However, lithium systems come with their own set of drawbacks. They are more costly and complex than photogrammetry, requiring expert knowledge and specialized equipment. Additionally, Lidar cannot capture colour and texture data, limiting its use in photorealistic mapping applications. These limitations should be carefully considered when deciding between photogrammetry and Lidar for a specific project.

Precision in Dense Vegetation

Lidar’s ability to accurately map dense vegetation and power lines sets it apart from photogrammetry, which struggles to process overlapping images in these environments. The laser pulses used by aerial lidar can penetrate dense vegetation, providing precise elevation data that is essential for accurate mapping. By utilizing lidar data, professionals can achieve a higher level of detail in their projects with the help of a lidar system. The use of lidar technologies, including the integration of a lidar unit, in mapping has proven to be a game-changer in various industries.

The horizontal accuracy of the Lidar in dense vegetation is approximately 0.05 meters, and the vegetated vertical accuracy is around 0.24 meters at the 95% confidence level. This level of precision makes Lidar especially valuable for applications in forestry management and power line mapping, where accurate elevation data in dense vegetation is crucial.

Cost and Complexity

While lithium offers numerous benefits in terms of accuracy and precision, it comes with a higher price tag and greater complexity compared to photogrammetry. Lidar sensors are typically more expensive than the cameras used for photogrammetry, and the processing software can also be more expensive. Furthermore, Lidar requires specialized equipment and expert knowledge to operate effectively.

Despite these drawbacks, Lidar can provide valuable data for specialized applications where its strengths in dense vegetation and low-light conditions outweigh the cost and complexity concerns. In these cases, the investment in Lidar technology may be justified by the improved accuracy and precision it offers.

Limitations

Lidar technology has its limitations, particularly when it comes to capturing colour and texture data. Unlike photogrammetry, which generates high-resolution images with rich colour and texture information, lithium point clouds lack this level of detail. However, a single lidar point cloud can still provide valuable data for various applications. This limits Lidar’s use in photorealistic mapping applications, where colour and texture are essential for creating visually appealing and accurate representations of the surveyed area.

Additionally, Lidar can experience performance degradation in adverse weather conditions and may have difficulty tracking objects in motion. Despite these limitations, lithium remains a powerful tool for specialized applications that demand high accuracy and precision in dense vegetation or low-light environments.

Hybrid Surveys: Combining Drone Photogrammetry and Lidar

Hybrid surveys offer an innovative solution to overcome the individual limitations of drone photogrammetry and laser by combining the best of both technologies. By integrating the accurate elevation data provided by Lidar with the photorealistic mapping capabilities of photogrammetry, hybrid surveys can deliver comprehensive and precise data for a wide range of applications.

The benefits of hybrid surveys extend beyond simply combining the strengths of photogrammetry and Lidar. They also offer the flexibility to adapt to varying project requirements and site conditions, enabling surveyors to choose the best data capture method for each specific situation. This versatility makes hybrid surveys an attractive option for many projects.

Benefits of Hybrid Surveys

By combining drone photogrammetry and Lidar, hybrid surveys provide the advantages of both technologies, offering accurate elevation data and photorealistic mapping. The fusion of these two methods allows for more comprehensive data collection, covering both surface textures and elevation details.

Hybrid surveys also offer the flexibility to adapt to a wide range of project requirements and site conditions. For example, a project that involves mapping densely vegetated areas and open spaces can benefit from the precision of lithium in dense vegetation, as well as the affordability and ease of use of photogrammetry in less dense areas. This adaptability ensures that hybrid surveys can cater to a variety of project needs, making them a valuable tool for many industries.

Use Cases

Hybrid surveys can be utilized in a wide range of industries and applications, such as large-scale infrastructure projects, environmental monitoring, and disaster response. In the construction and infrastructure sectors, a hybrid survey can provide detailed 3D data for design and planning purposes, as well as accurate progress monitoring during the construction phase.

In environmental and forestry management, hybrid surveys can provide valuable data for monitoring vegetation growth and health, assessing the impact of natural disasters, and tracking wildlife populations. Additionally, in the mining and aggregates industries, hybrid surveys can offer accurate volume calculations for stockpiles, as well as detailed site monitoring and mapping of inaccessible areas.

These diverse use cases demonstrate the versatility and value of hybrid surveys in various sectors.

Choosing the Right Technology for Your Project

Clogworks drone with Riegl laser scanner payload

Clogworks drone with Riegl laser scanner payload

Selecting the right technology for your project is crucial to ensure accurate and efficient data collection. When deciding between drone photogrammetry and Lidar, it is important to consider factors such as project requirements, budget, and desired outcomes. Each technology has its strengths and weaknesses, and the optimal choice will depend on the specific needs of the project.

By understanding the key differences, advantages, and disadvantages of photogrammetry and Lidar, as well as the benefits of hybrid surveys, you can make an informed decision on which method is best suited for your project.

Whichever technology you choose, it is essential to carefully consider your project’s requirements and goals to ensure that you select the most appropriate and effective solution.

Factors to Consider

When deciding between photogrammetry and laser for your project, it is important to consider factors such as accuracy, precision, cost, and the time required for the project. The quality of the equipment, software, and personnel required, as well as the desired outcomes, should also be taken into account when weighing the costs and benefits of each technology.

Additionally, consider the specific project requirements and the type of data needed. For example, if your project requires accurate elevation data in dense vegetation, lithium may be a better choice. On the other hand, if you need high-resolution imagery and a more affordable solution, photogrammetry may be the optimal choice.

Making the Decision

Ultimately, the best choice between photogrammetry and laser will depend on the specific requirements of your project. Photogrammetry is a versatile and affordable option that can be used for a wide range of applications, while Lidar excels in specialized applications where high precision and accuracy are essential.

By carefully considering the factors outlined above and weighing the pros and cons of each technology, you can make an informed decision based on your project’s unique needs and goals. Whether you choose photogrammetry, Lidar, or a hybrid survey, selecting the appropriate technology will help ensure accurate and efficient data collection for your project.

Industry Examples and Case Studies

3d point cloud of a drone survey for a planning application site

3D point cloud of a drone survey for a planning application site

To further illustrate the applications of drone photogrammetry, Lidar, and hybrid surveys, let’s explore some industry examples and case studies. These real-world examples showcase how these technologies are being utilized in various sectors to provide accurate, efficient, and cost-effective solutions for diverse project requirements.

From construction and infrastructure projects that benefit from photogrammetry for 3D mapping and progress monitoring, to environmental and forestry management where Lidar excels in capturing accurate elevation data in dense vegetation, these case studies demonstrate the versatility and value of drone photogrammetry, Lidar, and hybrid surveys in a range of industries.

Construction and Infrastructure

In the construction and infrastructure sectors, drone photogrammetry plays a crucial role in providing clear and precise maps for excavation planning, mapping, and surveying. Site managers can access accurate and up-to-date data to monitor progress, make informed decisions, and improve workflows. Additionally, drones can be used for topographic mapping, land surveys, and building smart cities.

On the other hand, lithium is particularly useful for structural analysis in construction and infrastructure projects. Its ability to detect changes in elevation and surface features can provide valuable insights for design and planning purposes, as well as for monitoring the structural integrity of buildings and infrastructure.

Environmental and Forestry Management

In environmental and forestry management, Lidar offers accurate elevation data in dense vegetation, making it ideal for monitoring vegetation growth and health, assessing the impact of natural disasters, and tracking wildlife populations. Photogrammetry can also be used in these settings, particularly in less dense areas where high-resolution imagery is more easily captured.

Both photogrammetry and Lidar can provide valuable data for environmental monitoring and decision-making, with each technology offering specific advantages depending on the project requirements and site conditions. By selecting the appropriate photogrammetry and lidar technologies, environmental and forestry managers can obtain the data they need to make informed decisions and protect our natural resources.

Mining and Aggregates

In the mining and aggregates industries, drone photogrammetry is widely used for accurate volume calculations of stockpiles and detailed site monitoring. By providing clear and precise maps, photogrammetry enables mining companies to plan excavation activities, monitor site safety, and manage water resources more effectively.

Lidar also has valuable applications in the mining and aggregates sector, particularly in mapping inaccessible areas and creating detailed 3D models of mine sites. By combining the strengths of both technologies, hybrid surveys can offer even more comprehensive and accurate data for mining and aggregate projects, helping to improve efficiency, safety, and decision-making in these industries.

Summary

In conclusion, drone photogrammetry, lithium, and hybrid surveys each offer unique advantages and limitations in the realm of aerial surveying. Photogrammetry is a versatile and affordable solution for a wide range of applications, while Lidar excels in specialized scenarios where high precision and accuracy are essential. Hybrid surveys combine the strengths of both technologies, providing comprehensive data to meet diverse project requirements.

By understanding the key differences, advantages, and disadvantages of photogrammetry and laser, as well as the benefits of hybrid surveys, you can make an informed decision on which method is best suited for your specific project needs. Armed with this knowledge, you can harness the power of these cutting-edge technologies to drive more accurate, efficient, and cost-effective outcomes for your projects.

Frequently Asked Questions

What is the difference between a drone survey and a LiDAR survey?

Photogrammetry is better at capturing finer details compared to LiDAR, which can provide more accurate measurements of larger areas.

What is the difference between LiDAR and photogrammetry surveying?

LiDAR uses lasers to generate a high-density point cloud to create digital surface models, while photogrammetry relies on traditional photography for data collection.

What is the difference between drone surveying and land surveying?

Drone survey technology offers faster and more accurate data acquisition compared to traditional land surveying methods. DTA drones can collect up to 1km2 of digital topographic imagery per day with minimal site disruption.

How do hybrid surveys combine the strengths of photogrammetry and Lidar?

Hybrid surveys combine the benefits of Lidar’s accurate elevation data and photogrammetry’s photorealistic mapping to create comprehensive and precise data for various applications.

These surveys are used for a variety of purposes, such as creating 3D models of buildings, mapping terrain, and creating digital elevation models. They are also used for land surveying, engineering, and environmental monitoring.

Hybrid surveys are hybrid surveys.

What are some industry examples and case studies of drone photogrammetry, Lidar, and hybrid surveys?

Industries such as construction, infrastructure management, environmental and forestry management, and mining and aggregates all use drone photogrammetry, lithium, and hybrid surveys to their benefit in various applications.

These surveys are used for a variety of purposes, including mapping, surveying, and monitoring. They provide accurate, up-to-date data that can be used to make informed decisions. Additionally, they can be used to detect changes in the environment, such as erosion or land subs.

Safer, quicker & cheaper



David Walker McInstCES AssocRICS avatar