Satellite Imagery for Sustainable Solutions

The sheer size of our seas and oceans, which cover nearly three-quarters of the Earth's surface, makes it almost impossible to gain a comprehensive understanding of marine ecosystems on the ground – or in the waters in this case. Using satellite imagery is the only way to do this.

Maritime surveillance is one of the ways satellites help protect the health of our oceans. Legislation obliges commercial trawlers to equip themselves with automatic identification system transponders. However, vessels that commit violations often disable these systems to avoid detection, leaving authorities in the dark as to their true activities. Satellite Earth observation can fill this gap, allowing governments and NGOs to monitor illegal fishing hotspots and identify offending vessels.

In addition to monitoring illegal activities at sea, satellite imagery allows us to better understand the state of the coasts, estimating the depth, quality and clarity of the water. Images can be colorised retrospectively by combining multispectral data, revealing hidden information not visible to the naked eye.

Promoting more sustainable agriculture

On land, the use of new multi-spectral channels also promotes sustainable agriculture and enables precise crop analysis. For example, in the image below, processing spectral information reveals the level of chlorophyll in the vegetation. Monitoring the chlorophyll content of leaves is essential to assess the nitrogen status of plants over time and allow farmers to take corrective action to improve crop health.

It is interesting to note that by combining the spectral richness of the image with modeling of the properties of the crops, it is possible to generate maps of biophysical parameters characterising the state and health of vegetation. For example, in image 3, the same image as in image 2 is used to measure the leaf area index, i.e. the amount of foliage on a unit of land. This information will help farmers make more informed decisions about specific crop needs within a plot, allowing for lower inputs and more sustainable water use.

Help prevent natural disasters

Natural disasters are becoming more frequent due to climate change, even in regions that were previously unaffected by extreme weather events.

It can be considered that there is no alternative to earth observation for effectively collecting data during natural disasters - especially when the assessment of the situation on the ground is deemed too dangerous. It should be noted that recent advances in satellite technology have dramatically increased the flexibility of using satellites. Emergency acquisition requests can now be processed within 30 minutes, greatly increasing the usefulness of satellites in crisis situations and natural disaster scenarios.

Take the example of the hurricane that hit Mananjary, Madagascar, earlier this year. Thanks to satellite imagery, local authorities and NGOs were able to quickly determine which areas had been flooded, in order to send aid and identify safe access routes.

In the aftermath of the hurricane and flooding, authorities again used satellite imagery to assess the extent of the damage. For example, by comparing images 7 and 8, they were able to identify damaged buildings and plan reconstruction work accordingly.