Making your final decision when purchasing a UAV camera or aerial inspection camera can be hard because new models are released almost monthly and finding the right one is not as easy as you may think. That is why we are taking a closer look at some critical camera features every user should look into before making their final decision. While most of them may seem and look the same, there are some important differences that separate the good ones from the bad ones. Let’s start with GSD or ground sample distance.
GSD defends the precision and reliability of the collected data. It is the most important factor that is affecting the precision of your maps and models. The GSD is measured in cm/pixel and it isn’t that hard to understand. If your GSD is 5cm, the accuracy of your imagery and modeling will be accurate to 5cm and no more than that. Standard GSD is measured in cm/pixel and usually ranges from 1 to 5. It is defined by several variables:
● Altitude of the image capture
● Size of camera sensor
● Camera resolution
● Focal length of the camera lens
● Aperture
Camera Resolution
Another important factor for aerial surveillance is definitely the camera resolution. This aspect is constantly changing and we are seeing higher pixel rates with every new model that comes out. Higher-resolution camera units always achieve a better GSD but they don’t guarantee an absolute advantage. When combined with small sensor size, higher MP resolutions makes images more likely to be affected by diffraction effects. This will decrease the sharpness of your images.
Sensor Size
There are different standard sizes for sensors so pay close attention to them. The larger ones have a better light-gathering ability at the same resolutions, while smaller ones will need greater exposure times to produce the same results. If you are striving for effectiveness, pay close attention to your sensor choices.
Camera Aperture
This measurement determines how exposed the sensor will be to the light. It is usually marked by f (ex f 2.0) which places all objects a few meters away from the camera in an infinity focus region. This puts various limitations on low-resolution cameras but on high ones as well. For example, low-resolution cameras will not be able to resolve point apart once the point of interest is too far away. Without variable aperture, cameras need to extend exposure times which always results in blurry images.
Focal Length
The focal length is a combination of sensor size, an effective distance from mirrors within the lens, and the curvature of the glass. Depending on the manufacturer, drone with cameras offer various lens options ranging from 10mm to 1200mm. The long focal length is usually linked with low resolution and is only used for visual inspection purposes. This makes such cameras unfit for surveys and 3-D generated asset inspections. When it comes to drone inspection, it is crucial to have a high-resolution camera, with a larger sensor and a 35mm equivalent focal length. This will provide more detail about any point of the inspected object while at the same time increasing image contrast for better 3D models and point clouds.
Conclusion
The drone market is constantly evolving and it will become more difficult to figure out which one is the right choice for your needs and purposes. Understanding your long term goals will help you determine the right model and size of your aerial inspection drone camera. Pay close attention to the details and stay informed at all times. Knowing all the different terms and sizes will help you make an informed decision that won’t come back to haunt you in the near or distant future.
