The Birkeland satellite has an antenna that picks up radar signals. Radar is used by ships to be able to sail safely. With radar, they can see what is around them. A radar emits radio waves. – Turning off the radar is probably something a ship’s captain is hesitant to do because of safety, says research director Trygve Sparr at the Norwegian Defense Research Institute. The satellite the institute has developed will give Norway and cooperating countries a more accurate picture of ship traffic than is currently available. – It will increase our ability to monitor our areas of interest, says Sparr. NOT ALL: AIS says that there are many ships in the northern waters, but not all ships appear on such an AIS plot. Photo: MarineTraffic Can be used to hide Ships are usually identified through something called AIS. This is the radio system that tells the outside world where the ship is. – We’ve seen that ships that want to stay hidden are shunned by AIS, says Sparr. The AIS equipment can also be manipulated in simple ways, says Sparr. Then they can send out the wrong position. A fishing vessel that is on the wrong side of a line can then claim that they are not doing anything wrong. Military vessels often do not use AIS. The Norwegian Defense Forces have also sailed without an active AIS system. When the frigate Helge Ingstad crashed, the AIS was switched off. Two satellites Detecting an active radar does not necessarily tell you where the transmitter is. If you see small waves from a rock that has hit the water, you don’t know for sure where the rock met the surface. If the radar signals are read by two receivers at the same time, it is possible to discover where they are being sent out. You get an even better position by following the signals over time. Birkeland therefore does not work alone. It is joined by the Dutch satellite Huygens. This satellite was launched at the same time as Birkeland. The two must keep a distance of between 15 and 25 kilometres. SIZE DOESN’T MATTER: Research Director Trygve Sparr together with models of Birkeland and the twin Huygens. They are so-called nanosatellites. Although very small, they function in the same way as larger and much more expensive satellites. Covering the entire earth Birkeland and Huygens will hover at a height of 535 kilometers above the ground. By staying so high, they can read signals from large areas. They also go in a so-called polar orbit. This means that they pass close to the two poles many times a day. It also means that the rotation of the Earth ensures that they can cover the entire surface. Polar orbits are particularly advantageous for the sea areas Norway is most interested in. A satellite in such an orbit passes more often over points near the polar regions than over points near the equator. POWERFUL THINGS: A Falcon 9 rocket from SpaceX has so much lifting power that it can take dozens of satellites with it on each trip. Photo: John Raoux / AP Hitchhiking with Elon Musk The two military satellites were launched into space on Tuesday this week. They were on a ride that Elon Musk’s company SpaceX named Transporter-6. On top of the Falcon 9 rocket were a number of other satellites. Sending up many small satellites at the same time with the same rocket means that each satellite owner has to pay less for the service. The Defense Research Institute confirms on Wednesday that contact has been established with both Birkeland and Huygens. Both satellites must be in good shape. – Now we will spend some time testing this system. It is new technology, and we want to find out how it can best be used, says Sparr.
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Norwegian spy satellite launched – news Norway – Overview of news from various parts of the country
