Uniqueness
Here are some key characteristics that make Earth observation imagery unique compared to alternative solutions:
Wide coverage – Satellites can capture imagery over large geographic areas, even remote regions that are difficult to access on the ground. This provides a synoptic view not possible from aerial or ground platforms.
High revisit frequency – Many Earth observation satellites have short revisit cycles, allowing frequent updates of imagery over the same area. This enables better monitoring of changes over time.
Multispectral and hyperspectral data – Satellite sensors can collect data in multiple spectral bands, beyond just visible light. This allows derivation of specialized vegetation, mineralogy, and bathymetry products.
All weather capability – Radar and some optical satellites can acquire valid imagery regardless of cloud cover or darkness. This ensures consistent temporal coverage.
Objective view – Satellite imagery provides an unbiased perspective from space, unaffected by boundaries or access restrictions on the ground.
Historical archive – Extensive archives exist for older sensors like Landsat, enabling analysis of land cover change over decades.
Global access – Satellite data is available for any part of the world, enabling a consistent methodology across regions.
Digital format – Satellite data is provided in analysis-ready digital formats suitable for computer processing and integration with other datasets.
In contrast, aerial imagery has higher resolution but smaller coverage per image. Ground surveys provide detailed in situ validation data but only for accessible points. Satellite imagery is unique in its consistent synoptic coverage, spectral information, and frequent revisit cycle over large areas.
How is This Information Useful?
Knowing the unique characteristics of Earth observation imagery is valuable as it allows us to understand the potential use cases and applications where this data can provide unique value.