Here's a rewritten and improved version of the original content in English, with added details to reach over 500 characters and make it sound more like a natural, human-written blog post:
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One of the most common questions we get is:
**"How accurate is the 3D model I created using Elios 2 visual data?"**
The answer isn't straightforward because the accuracy of your 3D model depends on the quality and precision of the data you used to generate it. However, there's a general rule of thumb that applies to all 3D models made from visual data.
**The theoretical maximum accuracy** of a 3D model built using Elios 2’s visual data is **three times the Ground Sampling Distance (GSD)**—which is the size of each pixel as it appears on the surface of the model.
Since the Elios 2 has a 4K camera, the best possible GSD is **0.25mm per pixel**, meaning the maximum theoretical accuracy of the model would be **0.75mm**. But for simplicity and clarity, we often round this up to **1mm** when discussing real-world applications.
This video demonstrates how achieving such high accuracy is possible by using reference dimensions close to the objects being measured:
[Embed video here]
In the video, several key factors were considered:
- The experiment was conducted under ideal conditions—no backlight, non-reflective surfaces, and sufficient texture.
- A small area (about 0.5 m²) was modeled to capture objects smaller than 5 cm.
- Two scale constraints and one orientation constraint were used across the area.
- Measurements were taken very near the scale points.
- The model wasn’t tied to any specific coordinate system, so only relative accuracy was evaluated.
While the Elios 2 can achieve up to **1mm accuracy** in controlled environments, this level of precision may not always be necessary or practical for every project. The desired accuracy should be determined early in the planning phase based on what you intend to do with the 3D model.
If you need precise measurements between parts of an object, you’ll want to fly closer, collect high-quality data, and plan accordingly. On the other hand, if you just need a general overview of a space, less precision might be sufficient.
Here are some important considerations for ensuring accuracy:
- **More reference points** are needed for larger areas.
- **Closer distance** improves GSD and overall accuracy.
- **Good lighting** and **smooth drone movement** reduce image blur.
- **Reflective surfaces** can be challenging due to fewer features.
- **Calibration** ensures clear, usable images.
Ground Sampling Distance (GSD) plays a crucial role in model accuracy. It refers to the distance between the centers of two adjacent pixels on the object being captured. As the camera gets closer, GSD decreases, allowing for finer detail in the model.
Thanks to its unique cage design, the Elios 2 can fly extremely close to objects, making it ideal for capturing high-resolution data. For example, in the video, it flew just **20 cm away** from the surface.
But again, the choice of GSD should align with your project needs. High accuracy requires more time and careful flight, while lower accuracy allows for faster coverage.
Did you know? The Elios 2 can achieve a GSD of **0.18 mm/px** at a distance of **30 cm**. This makes it a powerful tool for detailed inspections and modeling.
Keep in mind that **fisheye lenses** affect GSD differently depending on where the object is located in the image. Objects in the center have a smaller GSD, while those in the corners have a larger one.
When it comes to use cases, accuracy requirements vary. For example, a land survey might need lower accuracy, while an indoor inspection could require millimeter-level precision to locate defects or structural issues.
To learn more about accuracy and photogrammetry with the Elios 2, check out these resources:
- [Webinar] Indoor 3D Modeling Use Cases: Photogrammetry in Action
- [Webinar] Indoor 3D Modeling: Applications & Implications
- [Article] Why use photogrammetry to build 3D models of indoor spaces
- [Article] Building 3D models with Elios 2: How to acquire appropriate data for photogrammetry
- [Article] Building 3D models with Elios 2: Processing data with a photogrammetry software
Whether you're mapping large spaces or inspecting small components, understanding accuracy and how to optimize it will help you get the most out of your 3D models.
ShenZhen Jakeconn Precision Technology Co., Ltd. , https://www.jakeconn.com