Experts confirm that natural disasters such as floods or fires that occurred worldwide in 2021 are expected to intensify in the future. As for the fires, the causes are climate change, the prolonged increase in heat, and low rainfall rates and increasingly violent winds in the areas concerned.
Let’s try to take a look at the state of the art of satellites and their data and understand the extent of their power in the face of fires to participate in the efforts to save the planetary environment.
There is no shortage of examples to illustrate the power of satellites, whether they are optical, radar or infrared satellites. An impressive array of satellites observes the Earth for many purposes. Let’s take a look at some of them.
The SPOT N°6 and N°7 satellites have been specially designed to have a global coverage and the SPOT database for more than 30 years allows to see the evolution on the ground. They are heliosynchronous, which means that they fly over the same location always at the same mean local solar time. Any point on the earth is overflown every 26 days, the generation SPOT No. 6 and No. 7 has a resolution of 1.50 meters.
The Pleiades (1A and 1B) sun-synchronous satellites of CNES and Pleiades Neo (Neo 3 and Neo 4 launched in 2021 and Neo 5 and Neo 6 planned for 2022) have an image resolution of 70 cm with a daily visit frequency for the first Pleiades, reduced to 30 cm and a future twice-daily frequency for the Pleiades Neo of Airbus. The Pleiades 1A and 1B satellites are in the same orbit as the SPOT N°6 and N°7 satellites.
Similarly, the WorldView satellites of the American company Maxar Technologies are very high resolution. Cost-effective choices.
The Radar Constellation (TerraSAR-X, RadarSAT-2, RCM, ALOS-2, SAOCOM,…) provides a reliable basis for a broad portfolio of services and applications, benefiting from its accurate measurement and reliable monitoring capabilities with a visit frequency of less than 24 hours.
The analysis startup PlanetWatchers combines SPOT imagery with TerraSAR-X radar imagery (access time at any point on the globe less than 2.5 days) to detect changes in forest structure and biomass.
Radar imagery combined with optical imagery provides relevant and timely information on the different forest health conditions around the world. In recent years, the annual loss due to drought has affected more than one and a half million hectares, resulting in more than $150 million in financial losses, as well as the credibility of governments in the eyes of their populations, who are increasingly aware of the ecological choices made by their leaders.
The early detection of these areas by PlanetWatchers allows its clients to take preventive measures and to reduce yield losses up to 40%.
To detect fire outbreaks, there are no dedicated satellites yet, but it is recognized that thermal infrared satellites are the most useful for this purpose. In Europe, there is the Metop constellation (3 sun-synchronous satellites) and these satellites are mainly used for meteorology and can also be used for fire detection, as they pass over any point on the Earth in 29 days. The FireBIRD satellite of the DLR (German Center for Aeronautics and Astronautics) can also help since it is close to its end of life.
The Metop and Sentinel satellites of the European Copernicus program (especially Sentinel -1 and Sentinel-2 which observe land every 10 days with a resolution of 10m to 60m) monitor soil moisture, temperature to build risk maps.
The extracted data are mainly used for monitoring natural disasters (floods, cyclones, forest fires, landslides, erosion) and in the fields of land use (soil sealing, spatial planning, forest management), humanitarian aid, as well as for coastal monitoring.
We could have more satellites for these fires, but this would be too expensive according to ESA (European Space Agency).
The European Copernicus program is now giving priority objectives, such as the Emergency Management Service, which provides free archival or real-time mapping services based on satellite imagery on a global coverage and provided to concerned and authorized actors, civil protection authorities and humanitarian agencies.
To extinguish or to let burn?
We end up asking ourselves why man is able today to invest crazy sums of money for space tourism with distant and uncertain benefits, while every year human lives suffer on earth when these sufferings could be avoided with a greater willingness to invest in more useful constellations. The great fires that have occurred this summer 2021 in different parts of the globe, almost a few days after the great announcements of small tours in Space by billionaires, give us the right to ask ourselves the question: if Space allows to accomplish the craziest dreams, why wouldn’t Space allow to avoid the occurrence of great catastrophes? And this is particularly true for fires.
The earth’s climate is getting hotter and hotter, its soils are getting drier and drier, there is less and less precipitation in some regions, more and more in others, and winds are getting stronger and stronger. Forests are increasingly threatened by climate change. What space-based tools are needed to warn people and save precious time?
It could be very useful to have an early warning system capable of monitoring large forest areas in real time and detecting the start of a fire larger than a few square meters to allow interventions before it spreads.
Only satellites are today able to collect data on every point of the globe or a given area of the globe in real time, to detect heat rates, locate areas at risk and identify fire outbreaks early.
Faced with a fire risk distributed over multiple areas, the natural operational or political decision to intervene may be paralyzed by the practical impossibility of dealing with the number of locations involved and the uncertainty of where to act precisely and preventively when the area may be large.
Faced with a fire outbreak detected at an early stage, the situation is different: action must be taken because the fire is there, the location of the outbreak is known and it is still easily treatable without inordinate efforts. The precise knowledge of all the fire starts also allows a global and optimized planning of the extinguishing means.
Today, despite the thousands of low earth orbit (LEO) satellites put into orbit for other purposes and probably capable of a resolution between 3 and 5 m and all the sun-synchronous satellites capable of a resolution of 30 cm, it is necessary to wait for these satellites to pass over the places concerned and to be equipped with the appropriate detectors to know the fire situation. We are therefore far from real-time monitoring of the surface of the globe or of a continent in order to detect fire outbreaks when they are still very limited on the surface, allowing easy extinction.
Ms Claire Tinel, CNES representative to the International Charter on Space and Major Disasters, explains that it seems impossible to achieve this objective to date within the framework of the Charter, as it would involve far too many resources in terms of programming and production costs. The action of the 17 space agencies involved in the Charter is humanitarian and without exchange of funds and as such remains limited.
According to some specialists consulted, if we wanted to have a large global early fire detection system, we would have to increase the number of satellites. Metop-type satellites would be suitable, even if they were to improve their resolution a little more. The problem is to make them pass as often as possible over each point of the Earth. We would then need dozens of them of average size. A small constellation in short. Another possible solution would be the use of LEO satellites (low earth orbit satellites) equipped with telephoto lenses adapted to low earth orbit satellite constellations when miniaturization engineers have found the solution.
This could be the choice of a government or an international organization, or even of American, Arab, Russian or Chinese billionaires anxious to reduce the vicious circle of global warming that is causing more and more fires.
The approximate cost of implementing such a project would represent about one billion Euros, or 4 days of the cost of the war in Afghanistan estimated by Joe Biden at 300 million dollars per day (250 million Euros per day) for 20 years on the US budget.
We can ask ourselves: why hasn’t it been done or isn’t it being done?
The space actors have pushed their efforts very far and the capacity of satellites in orbit is no longer to be demonstrated in terms of quality and resolution of radar images, infrared, etc…
To date, national projects (such as ADELIE and its detection cameras in some places), international and European projects such as the Charter and Copernicus (especially the EFFIS program) are going in the right direction by centralizing certain data but are still too timid and technologically limited in their means and objectives: the awareness of the urgency of the action of real-time detection of fire outbreaks and other natural disasters in a global or at least continental way has not yet occurred among decision-makers, prescribers and authorities. Even though the technical tools exist for this, at a bearable cost.
However, if we take a closer look, there would be many advantages in terms of saving human lives, economic impact, biodiversity, to an international cooperation, capable of putting the necessary means to cover the globe or a continent in satellites for prevention and detection in real time of fire starts, when it is still possible to extinguish a fire start without excessive or futile efforts
Like the International Charter for Space and Disasters initiated by CNES and ESA (European Space Agency), an optimization of the use of all available means (ground, flight) at the level of the members participating in this project could be implemented as soon as an alert is issued from a simple application, fed with real-time satellite information and others. Combined with rapid detection in real time, this optimization would allow a very significant gain in efficiency.
The arrival of low orbit satellites intended to be produced in thousands of copies has reshuffled the deck in terms of the unit cost of a satellite. The die has not been completely cast in the face of the climate emergency, which we must realize is just around the corner.
There have always been and will always be life-saving innovations in space. Faced with the climate emergency, let’s hope that the right decisions to accelerate them will be taken.
Nadia Didelot for AeroMorning