![]() ![]() For example, when trying to detect cars from an aircraft, the ground sampling distance should be no larger than half of the width of the smallest car expected. The GSD should also be at least half of the size of the smallest detail to be measure optically. This equates to measuring an object in centimeters instead of in meters. This blog post explores the contributing factors to attaining a desired ground resolution (also known as the ground sampling distance (GSD)).Ī higher ground resolution requires a smaller ground sampling distance. In addition to availability images, scaling and resolution are often limiting factors in obtaining high-quality, easy-to-view imagery.When equipping an aerial vehicle with imaging equipment, it is important to make out the objects of interest with enough detail for the desired task at hand. Hopefully this post provides you with a better understanding of the factors behind the quality and clarity of aerial photography. Keep in mind when ordering aerial photography that higher resolution images generate larger file sizes, making high-resolution photos of large areas more difficult to view, manipulate, export, and transfer without the proper software. For example, most current NAIP imagery is collected at 1-meter resolution, which provides plenty of clarity to view buildings and other structures as opposed to older NAIP imagery, which is generally closer to a 2-meter resolution. The smaller the denomination is, the higher the quality and spatial accuracy. ![]() Resolution in terms of spatial accuracy is generally described as 1-meter resolution or 3-meter resolution. For example, if the original frame is scanned at 600 DPI, exporting a digital image at 1,000 DPI of the same frame will look no better than it would exporting at 600 DPI. DPI resolution of an image will only be as good as the resolution in which the digital image was first scanned. DPI constitutes the resolution in which the original frame or film was scanned as well as exported digitally. Resolution can be characterized in two different ways: dots-per-inch (DPI) and spatial accuracy. Likewise, photos with higher resolution provide a better opportunity for clearer magnification of certain features on a photograph. The smaller the scale of the original photo, the better the clarity when zoomed-in closely – compared to a higher-scaled photo of the same resolution. The original scale also affects the quality of the photo when zoomed at closer levels. Scales are typically denoted as a ratio of inches or as inches to feet or miles. The various types of cameras used to capture images from above include aerial mapping cameras, reconnaissance cameras, strip cameras, panoramic cameras, multi-lens cameras, and digital cameras. The original scale of the photo depends on the type of camera used, the altitude of the flight, and the purpose of the flight. Scaling is one of the more difficult aspects of aerial photography to explain. In this post, we will discuss the two main factors that determine the quality of aerial photography: scaling and resolution. ![]() In my previous blog post, we explored the history of aerial photography. ![]()
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