Using Satellite Imagery for Conservation

Satellite imagery can be used beyond its visual properties. Pixels pertaining to different satellite bands contain information that can help us distinguish features on the earth's surface.

Take for instance the uninhabited islands of Plana Cays located near the Bahamas. We could simply take this true color image and digitize the islands in a Geographic Information System (GIS) application. This can be an effective way to translate content into a digital format with a spatial reference. Nonetheless, it is a time consuming process and the user must ensure that they are careful with the digitization process.

Sentinel-2 11-11-2024 True Color Enhanced Image by Orbital Perspective.

However, we can also use satellite imagery to better discern such features and extract a digital representation. Because the reflectance of water, vegetation and soil respond differently in the Near Infra-Red part of the electromagnetic spectrum, we can use a satellite band with the corresponding wavelength to extract pixels representing the islands.

Satellite remote sensing of the variability of the continental hydrology cycle in the lower Mekong basin over the last two decades - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Spectral-signatures-of-soil-vegetation-and-clear-water-as-a-function-of-wavelengths-from_fig3_327860369 [accessed 1 Feb 2025]

Sentinel-2 11-11-2024 Band 8, Near Infra-red. By Orbital Perspective.

After running the analysis to identify the islands, we are left with pixels highlighting these features. Thereafter, a conversion is run from pixels to a line format. We notice that other features are also highlighted, for instance the clouds. We have to perform quality control and quality assurance of the output to remove unwanted features so that we can generate high quality data.

Sentinel-2 11-11-2024 Band 8, Near Infra-red and pixels representing features of interest in orange. By Orbital Perspective.

The output of the analysis. A set of polygons representing the physical boundary of the islands for the date 11-11-2024 . By Orbital Perspective.

The polygon output can then be used to derive other useful information about the islands, such as area and perimeter, and can be used as input for other analysis within a GIS or a related application.

This type of workflow is an example of how Orbital Perspective's GIS solutions and insights can help your organization in leveraging satellite imagery in the public domain. We can see a repeated theme in the use of satellite imagery within the following Coral Reef and Island Survey report authored by the Nature Conservancy showcasing the importance of having the right visuals in order to make the right impact.

Reach out today through our website or contact us directly via email (orb.perspective@gmail.com) to chat more about how satellite imagery in the public domain could be part of your next project.