When it comes to the business of drone surveying, understanding elevation models is paramount. Three of the most used models are the Digital Terrain Model (DTM), the Digital Elevation Model (DEM), and the Digital Surface Model (DSM). These models serve as crucial tools in understanding terrain details. They are instrumental in various fields from land development, construction volumetrics, and surveying. In this article, we examine the fundamentals of elevation models, their significance in drone surveying, and applications for their use across different industries.
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Dense point clouds derived from drone methods provide an invaluable data source to fill the gap between globally available low-resolution DEMs and highly accurate terrestrial surveys.
Understanding Elevation Models
What are Digital Elevation Models (DEMs)?
Digital Elevation Models (DEMs) serve as fundamental components in drone surveying. At their core, DEMs provide a visual representation of elevation data for every point captured within a designated area. Unlike traditional maps that depict surface features, DEMs utilize color gradients to indicate variations in elevation, offering a nuanced understanding of the terrain’s topography.
DEMs are structured as raster datasets, essentially grids that assign elevation values to each point based on its horizontal coordinates (x, y) and vertical elevation (z). The highly detailed information within a DEM is determined by the size of grid cells; smaller cells yield higher resolution and detail, enabling precise modeling of exact terrain features.
What's included in YOUR GUIDE...
A Proven Roadmap of Success for Implementing Drones in Construction.
A List of Red Flags to Avoid When Hiring Drone Service Providers.
How to Persuade Your Leadership Team to Leverage Drones on Every Jobsite.
What’s the Difference Between Digital Terrain Models (DTMs) and Digital Surface Models (DSMs)?
While DEMs encompass a broader category of elevation models, they can be further delineated into Digital Terrain Models (DTMs) and Digital Surface Models (DSMs). Understanding the distinction between these two is pivotal in comprehending their respective applications.
DTMs represent a simplified rendition of the Earth’s surface, focusing solely on the natural terrain and ground features. In contrast, DSMs encompass a more comprehensive scope, incorporating all captured points, including both natural and man-made structures such as buildings, vegetation, infrastructure, and even lines on a parking lot or roadway.
Visually, the disparity between DTMs and DSMs becomes apparent through their representation. A DTM predominantly follows the contours of the ground, whereas a DSM encompasses the peaks and valleys of surface features, including elevated structures and vegetation.
In essence, while DTMs offer insights into the bare-earth landscape, DSMs provide a holistic view of both the terrain and its built environment. This difference between the two underscores the versatility and applicable use of elevation models in various surveying and mapping endeavors.
Using Drones for Elevation Modeling
Aerial Methods of Capturing Elevation: LiDAR vs. Photogrammetry
Central to capturing elevation models are two primary technologies: LiDAR (Light Detection and Ranging) and photogrammetry. LiDAR emits laser pulses towards the Earth’s surface, measuring the time it takes for the light to return to create precise three-dimensional point clouds. This technology excels in accuracy, even in vegetated areas, as it penetrates foliage.
Point clouds, derived from LiDAR, are a collection of data points mapped in three dimensions where each point has its own X, Y, and Z value depending on where it is in space, serve as the basis for detailed Digital Elevation Models (DEMs) and Digital Terrain Models (DTMs). In addition to LiDAR, photogrammetry utilizes high-resolution aerial imagery to reconstruct three-dimensional terrain models. Despite its effectiveness in capturing surface details, photogrammetry may face challenges in vegetated areas due to obstructions on the Earth’s surface, hindering accurate elevation measurements.
Related Article – The Truth Behind Drone-Based Volumetric Surveys: How Accurate Are They?
Applications of Elevation Models
Elevation models generated through drone-based surveys have diverse applications across many industries and disciplines. They are crucial in infrastructure management for site planning, grading, earthwork analysis, and optimizing project outcomes. In hydrology and environmental monitoring, these models aid in watershed delineation, flood risk assessment, and terrain analysis, enabling effective mitigation strategies. They also contribute to urban planning, land-use mapping, and natural resource management by describing land cover types in detail.
In addition, elevation models produced by drone data can assess terrain suitability, and analyze changes in landscape which are crucial for land development. These models also play a vital role in disaster management and emergency response efforts, assisting in assessing the impact of natural disasters and facilitating timely evacuation plans. Overall, their versatility drives innovation and enhances decision-making processes across various sectors.
Getting Started with Drone Elevation Models
Elevation models generated through drone-based surveys have revolutionized the landscape of surveying and mapping, offering unparalleled insights into terrain features and topographic variations. From infrastructure planning to environmental management, these models serve as indispensable tools in a wide range of applications, driving innovation and enhancing decision-making processes across diverse industries.
However, regardless of the technology employed, the accuracy and reliability of elevation models depend on the expertise and experience of drone service providers. When looking for drone services, it is essential to ensure that providers are licensed by the FAA and possess extensive experience in handling specific project requirements. At The Drone Life, our highly trained and experienced pilots are equipped to deliver exceptional results tailored to your project needs. Schedule a free consultation today to learn more about how our expertise can elevate your project to new heights.
What's included in YOUR GUIDE...
A Proven Roadmap of Success for Implementing Drones in Construction.
A List of Red Flags to Avoid When Hiring Drone Service Providers.
How to Persuade Your Leadership Team to Leverage Drones on Every Jobsite.
