Anyone who thought that satellites already map the earth in every possible way is almost right. Tuesday, April 29 at 11.15 Dutch time, the European satellite Biomass will be launched to view the earth in one of the last unexplored areas of the radar spectrum: the P-band. This makes the amount of wood, and therefore also the amount of stored CO2in tropical forests measurable for the first time.
“The P-band is about radio waves of 70 centimeters, and they are sensitive to the dimensions of tribes and branches,” says Dirk Bernaerts, program manager of the European space agency ESA, during a presentation in Noordwijk prior to the launch. Although existing satellites already map forests with the help of photos or radar images. Bernaerts: “But then you mainly see the green of the tree crowns, not how much wood is under it.”
White spots in the tropics
Over the next five years, Biomass will have to map the world stock of living wood in tons per square kilometer. Hence the name. A large white spot is filled in especially for tropical forests. “According to estimates, 45 percent of biomass are on land in tropical forests,” says Bernaerts, “but they have been very poorly mapped.” In moderate regions, for example Europe, the amount of cubic meters of wood in forests is reasonably known thanks to studies on the spot, but such surveys are much less done in the tropics.
“We suspect that the biomass in tropical forests is considerably underestimated,” says Johannes Reiche, specialist in radar measurements of forests at Wageningen University, who will use biomass data for scientific research. Since tropical forests play a major role in the global cycle of CO2the data will help make climate models more reliable. The urgency of protecting tropical forests is now great. On average, hundreds of square kilometers per day are lost in deforestation, often in favor of agriculture.
The unusual radar golf length explains the peculiar appearance of the satellite: the standard box-shape with sun panels has a 12 meter wide, folding antenna that looks suspiciously like an umbrella. He also challenges an umbrella, after the launch on board a Vega-C rocket from the ESA space center Kourou in Frans Guyana.
A phased arraya flat antenna on the box section, shoots radar pulses of 100 watts up, which are reflected back to the earth via the umbrella. There they bounce back again, whether or not hindered by tree trunks, branches or the forest floor itself. About a ten trillion of the original pulse comes back on the antenna via the umbrella to be measured. Even longer radar golf lengths are forbidden area: those wavelengths use military satellites to detect launches of nuclear missiles.
Proof of companies
Not only scientists will purchase the data from the satellite, but also companies such as the Utrecht company Satelligence, that other companies inform satellite images about matters such as deforestation, water shortages.
“Our customers are producers of cocoa, coffee, soy, palm oil and other crops,” says director Niels Wielaard, who founded Satelligence in 2016. “For example, they need independent evidence that their activities do not lead to deforestation. We can deliver that.”
Plantage holders, but also large food companies and their financiers run risks if they cause deforestation. “Then you have to think of reputation damage, but also legislation on deforestation that is coming or already applies.” In December this year, the European EURD legislation (EU Deforestation Regulation), with substantial fines for companies participating in deforestation. The US, China, and Brazil have also announced legislation. Wielaard: “Even a small batch in the food market soon has about ten thousand plantations such as suppliers, large parties up to half a million. We can split it into plots and summarize different sources.”
On the other hand, Co.2 In forests also yield money via carbon credits and other programs to compensate for emissions. In addition to deforestation, satellites can also map water shortages, floods, forest fires, or damage to vulnerable forest areas with rare species. Satelligence, with now 40 employees and seven offices worldwide, now works with data from existing satellites, but Biomass can offer additions to this, Wielaard expects: “We expect to be able to see much Co much more precisely2 is stored there. And we may also be able to distinguish different crops, which are still just green now. “