DigitalGlobe's WorldView-2 satellite provides the only high-resolution 8-band multispectral commercial imagery available. WorldView-2's eight spectral sensors are narrowly focused and provide complete coverage of the visual spectrum, along with two near-infrared bands. Together the bands are designed to improve the segmentation and classification of land and aquatic features beyond any other space-based remote sensing platform.
Applications for 8-Band Imagery
DigitalGlobe's high-resolution 8-band imagery is a powerful tool for remote sensing, and is being applied to three primary areas: Bathymetry, Vegetative Analysis and Feature Extraction.
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Bathymetry
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8-band imagery offers a significant improvement over four band imagery in the ability to conduct accurate bathymetric measurements from space. The addition of the Coastal Blue band, and the refinement of the Green band are providing significant advantages in measuring bathymetry at greater depths, and the Yellow, Red Edge and occasionally NIR1, are very useful in shallow waters when they correlate with sub-aquatic vegetation, coral or seafloor substrate.
Accurate bathymetry is very important for near shore navigation, and coastal zone monitoring, as the marine environment is particularly susceptible to dramatic changes due to storms, earthquakes and tsunamis.
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Vegetative Analysis
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The Red Edge and Yellow bands are specifically designed to detect key vegetative phenomena. The Red Edge band marks the transition between where plant pigments absorb visible light, and reflect infrared light. Its position varies dependent on the species, and shifts according to changes in plant health, age, and growth rate. Similarly, the Yellow band can detect changes the amount of leaf chlorophyll and other key pigments that mark vegetation stress.
Vegetative analysis is the key to building detailed land cover classification maps, which are particularly important for mapping changes due to climate change, urban sprawl, and environmental contamination. Land cover maps are also playing an important role in the global carbon trading market, and the ability to monitor deforestation and subsequent reforestation activities.
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Feature Extraction
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Not only does WorldView-2 provide complete coverage of the visible to near infrared spectrum, but each of the spectral bands is very tightly focused on the target wavelengths of light, enabling a clearer segmentation of the spectral response from objects on the ground. The very high spatial resolution also provides detailed morphological and textural attributes. This additional information is leveraged by sophisticated feature extraction algorithms to produce more accurate classifiers that can segment different man-made structures, distinguish crop types or discriminate among tree types.
Accurate feature extraction is critical for civil governments, where taxation is often dependent on land use, such as changes in impermeable surfaces, or the presence of swimming pools. In addition, feature extraction plays a critical role in accurate change detection which can be a vital tool in post-disaster response coordination.
Technical Information and Imagery
Additional technical information is available in the datasheets attached to this page. For additional information, please contact a DigitalGlobe representative.
