Tips for Taking Photogrammetry Images Using Drone-Based Cameras
One aspect that photogrammetry will never have room for compromise on is the type of camera used. While you might have a fantastic camera, some level of skill will be needed to bring out the best of the photos in specific situations. Luckily, this skill trickles down to the right preparation and the software you opt to use.
Here are four insightful tips for taking useful and quality photogrammetry images:
Pick The Right Camera With a Good GSD
GSD (ground sample distance) simply refers to the spatial resolution of the camera which is the distance between any two-pixel centers that are measured on the ground. This can be considered the ‘accuracy limit’ for your camera. It can be impacted by various factors like the camera resolution and aperture, size of camera sensors, image capture altitude and the lens’ focal length.
For amazing images, work with a camera that is compatible with your photogrammetry software and has large sensors and a high resolution, according to PhotoModeler. As for drone surveys, a mechanical shutter can be better than a rolling shutter when it comes to developing 3D models to avoid any distortion of the images. Additionally, opt for a camera with quick autofocus to eliminate instances where your photos are blurred.
Is The Surface Good Enough?
Before you can begin to take photos, it is vital to determine whether the surfaces are compatible with the photogrammetry process. In case you are creating a 3D model, the reconstruction software assesses the various pictures that you take and when a particular group of pixels matches, it makes a point on the model. This means that it can be tricky to reconstruct images from moving objects or even objects that keep on readjusting their appeal.
This effect will include objects such as liquids, overly shiny objects, transparent items and even flat surfaced objects which have a similar color all through. To achieve a good point cloud, consider using still objects with easily differentiable features. For flat objects with singular colors throughout, consider making markings on the object to distinguish the various pixels.
Where Will You Take The Picture From?
Traveling from one capture location to another takes time, not to mention the time needed to deploy the equipment. Consequently, it is essential to plan the shooting trip wisely to avoid time wastage. Among the best ways to make the most of your time is to choose a single area which has enough assets to derive as much information as you need.
Consider factors like whether the area is public or private as private property has to be respected. Additionally, consider the laws of the areas you want to take photos from since a couple of locations have restrictions on the use of drones. When taking photos in a public environment, factor in movement by people as this might distort your images.
When Will You Take The Photo?
Weather affects photogrammetry in a variety of ways. Elements such as snow and rain can not only lead to poor image reconstruction but also mean trouble when it comes to flying drones during such inclement weather. Additionally, your camera’s lens will be affected by the water.
Sunshine, on the other hand, produces strong directional shadows and highlights. Windy environments will also affect the reconstruction of the images since most parts of the environment will be moving. To be safe, take the photos at a time when the weather is calm.
The best photogrammetry process will require various factors to be in perfect synchrony. The aim is to refine these aspects to make the most of your equipment. Consider the above tips to reconstruct amazing photogrammetry images.