All satellite imagery is affected at some level by lightwave scattering from haze, water vapor and particulates in the atmosphere. Every optical satellite in orbit peers at Earth through the same atmosphere, and each and every satellite image collected is impacted differently because atmospheric conditions are constantly changing.
Understanding and adjusting for the atmosphere is a fact of life in this business. That’s why we’re so excited to introduce DigitalGlobe Atmospheric Compensation (AComp), a game-changing tool that enhances the usability, quality and availability of our industry-leading satellite imagery. What does it do? Put simply, AComp lets us see through the haze.
Why is AComp good news for users of satellite imagery and data? A picture is worth a thousand words:
The unprocessed image on the left was clearly collected on a day with challenging atmospheric conditions. You can make out the features on the ground, but there’s a uniform haze that reduces the quality of the image, and its usefulness for some applications. The image on the right uses AComp to clear the air. AComp makes this image better by mitigating the effects of the atmosphere between satellite and ground. By accurately representing the surface reflectance of the ground, AComp delivers the highest quality imagery.
Let’s look at this in another way. Have you ever wondered why the sky is blue? We tend to take it for granted, but there’s an actual technical answer: the sky is blue because of Rayleigh scattering. When sunlight approaches our planet, it interacts with molecules in Earth’s atmosphere and is scattered into its constituent colors. The blue light scatters more efficiently, thereby saturating the sky with its color.
How does this relate to satellite imaging and AComp? From the perspective of the Earth’s surface, our atmosphere is a protective shield—and we’re all thankful for it. But from a satellite’s perspective it’s a barrier to be crossed. When a satellite takes an image, the light reflecting from the ground is impacted by the atmosphere and can affect the visual aesthetics of the image. For example, place a straw in a glass of water and look at the straw from the side. The straw will appear to be bent or disjointed because the water, like the atmosphere, can bend, scatter or refract the light, and this affects what you see. AComp significantly improves image quality by adjusting for this atmospheric scattering across diverse conditions.
The mapping industry has used and developed various atmospheric compensation tools requiring high and low levels of expertise with varying outputs of quality. DigitalGlobe AComp is powered by our proprietary algorithm, which is unique in the industry. It promises real benefits to everyone who uses optical satellite data—from consumers of foundational images who will be able to solve real-world problems, to image scientists who need surface reflectance to have consistent spectral information to perform image analytics.
What are the benefits of AComp?
- More of our 16-plus year time-lapse archive of high-resolution imagery is unlocked
- Reduced collection failure rates due to haze
- Improved quality for imagery from new collection
- Enhanced customer experience with DigitalGlobe products
Check out part 3 of our Maximizing Image Availability blog series, which discusses how we use weather modeling to improve collection planning.