Conventional satellite images are interpreted in “natural color” using red, green and blue spectral bands. But advanced satellites like WorldView-3 (launched in 2015) use infrared and shortwave infrared (SWIR) sensors to collect information beyond the visible spectrum—providing a deeper understanding of what’s happening on our planet. That deeper understanding is known as spectral resolution, which measures all of the different you can see and interpret within each pixel of an image.
WorldView-3 satellite collects sixteen multispectral bands. While it has industry-leading image quality in the visible spectrum of red to violet, the majority of the information collected by WorldView-3 (and DigitalGlobe’s other sensors) actually lies outside the “colors of the rainbow.” Using near-infrared imagery, objects that appear identical in the visible spectrum (like natural grass and artificial turf on a football field) can be differentiated because of their distinct spectral signatures. Multispectral imaging also allows you to see through some of the noise that can obstruct the signal you’re seeking.
With a combination of visible, near-infrared and SWIR, we gain new and valuable insights, including:
- Vegetative analysis and classification of plant type, age and health
- Mineral identification for energy and mining exploration
- Man-made material identification of things like steel, fiberglass, and paint
- Penetrating smoke and haze to help emergency response and wildfire management
Here’s a great example of our advanced spectral resolution and what it can reveal. We’ve partnered with the World Resources Institute to monitor annual agricultural fires used to illegally harvest palm oil in Indonesia. We used multispectral imagery to understand how and where the fires are burning, with the hopes that this information can be used to stop them where they’re spreading. The following pictures were all collected with WorldView-3 on the same pass. By selecting different band combinations, we can address different needs and applications.
The picture above is a natural-color image that uses red, green and blue spectral bands. The image appears as the human eye would see it in person; however, beneath the haze and smoke, you can barely make out the burned areas.
When you replace the red band with the near-infrared band (just outside the visible spectrum), then visualize it in false color, some of the haze disappears. You can clearly see the fire demarcation line and distinguish between healthy vegetation (red) and burned or dead vegetation (brown or green). This image serves to best support first responders and conduct vegetative analysis.
And with the SWIR band, you can see through the smoke to reveal fire hotspots. Understanding the exact location and intensity of these combustion centers helps responders to dispatch resources more safely and effectively.
DigitalGlobe’s constellation of advanced satellites and our 16-year library of Earth imagery offer industry-leading spatial resolution. This ability unlocks all kinds of ground-level insights that would otherwise be hidden—helping save time, resources and lives.