The world’s biggest space-based radar will measure Earth’s forests from orbit

These indirect systems depend on a mixture of field samples – they roam the forests between trees to measure their height and diameter – and remote sensing techniques such as Lidar scanners, which can be transported over the forests on aircraft or drones and used to measure Treetop height on airlines. This approach has succeeded well in North America and Europe, which has firm forest management systems. “People know every tree there, and they take a lot of measurements,” says Skipal.

But most of the world’s trees are in less equal places, such as the Amazon Forest, where less than 20 % of the forests were deeply studied on Earth. To learn about the biomass in those distant areas, most of which cannot be accessible, space -based forest sensor is the only possible option. The problem is that the satellites that are currently we have in orbit are not equipped to monitor trees.

The tropical forests that were seen from space looks like a luxurious green carpet, because all we can see is the parts of the trees; From pictures like this, we cannot know how high or thick trees. We have radars on satellites such as Sentinel 1, short radio wavelengths such as those in the C domain, which decrease between 3.9 and 7.5 cm. These bounces from the sheets and smaller branches and cannot penetrate the forest to the ground.

That is why the task of the biomus, ESA went with the P-Pand radar. The P-Pand radio waves, which are about 10 times long in wavelength, can see the largest branches and trunks of trees, where most of its mass is stored. But the installation of the P-Pand radar system on the satellite is not easy. The first problem is the size.

“The radar systems scale with wavelengths – the longer the wavelength, the larger the antennas. To enable it to carry the Pom” radar, the Airbus engineers had to make the satellite of the biomass a width two meters, two meters, and four meters length. A radar antenna is 12 meters. It is sitting on a long and multi -sedative boom, and it was, and it was Airbus engineers must fold it like a giant umbrella to suit it in the Vega C missile that raises it to orbit.

The massive size, though, is just one reason because we generally avoided sending P-Pand radars to space. These radar systems are prohibited in space by the International Communications Union regulations, and for a good reason: interference.

“Settling the basic frequency in the P range is for huge sotr [single-object-tracking radars] Americans use the discovery of continents. This, of course, is a problem for us. To obtain an exemption from the ban on P-Pand spacecraft, the European Space Agency had to approve many restrictions, the most painful was to stop the vital mass radar over North America and Europe to avoid interference with Sotr coverage.