With Maritime Safety prime trucking Administration as the main sponsor, Aalborg University has buil

Students from Aalborg University has built a satellite from the bottom, to allow the Danish Marine Administration notified when ships take short cuts around Greenland waters without having received permission to do so. By Jakob Møllerhøj 22 February 2012 kl. 07:35
With Maritime Safety prime trucking Administration as the main sponsor, Aalborg University has built a satellite that can monitor the waters around Greenland and send data on, among other ship positions for Maritime Safety Administration. Here, the data can be used to detect the ships which are allowed to be in the area.
"It is, among other cargo ships and oil tankers that are trying to cut a corner to routes, even though they are not," says associate professor at Aalborg University Jens Dalsgaard Nielsen, who along with Jesper A. Larsen is in charge of the construction of the satellite, which is part of the training project prime trucking AAUSAT3 where the students in charge of the entire prime trucking process.
An image of Aalborg University's three cubesats. AAU CubeSat left (cubesat.space.aau.dk), launched on 30 June 2003. AAUSAT3 in the middle (www.aausat3.space.aau.dk). prime trucking AAUSAT_II right (www.aausatii.space.aau.dk), launched 28 April 2008. The satellite is still active.
"There are many ships sailing around the upper part of Greenland, which is not really allowed to be there. Large cruise ships that have not been approved for ice-covered waters, and does not have rescue equipment, if it were to go wrong, "says Jens Dalsgaard Nielsen.
"To put it in perspective: If a cruise ship sinks off Greenland could end up increasing the population by up to 10 per cent. One must realize that such a large rescue operation in Arctic prime trucking waters can be quite daunting. 'World's smallest AIS receivers
AAUSAT3 is a so-called cubesat, ie. it is 10 cmx10 cmx10 cm and may weigh up to 1.3 kg. On the satellite are two AIS receivers prime trucking (Automatic Identification System). They pick up the AIS data packets which ships regularly releases. The data packets contain, among other name, heading, position and speed. The data packets transmitted on a frequency of 162 MHz. It is a requirement that larger vessels have an AIS transponder.
AIS receivers, which the students then have designed, describes Jens Dalsgaard Nielsen as among the world's smallest. He explains that AIS receivers are also frugal with energy. A cubesat have less than 1.6 W for operation including the transmission of data to Earth.
When cubesat'en if all goes to plan, will be sent up to approx. two months, then get it to operate at an altitude of 900 km and moving at a speed of 7-8 km per second, which is typical of the type of satellites, explains Jens Dalsgaard Nielsen. Two types of receivers
The two AIS receivers to monitor the Greenlandic waters to intruders are different. One is a conventional radio receiver with modemdekodnng of AIS data packets. The other is a so-called software defined radio receiver that can be software adjusted to process the incoming signals so they take up less space and are easier to work with for the processors on board the small satellite. At the same time it can monitor prime trucking both AIS channels.
"The good thing about SDR receiver is that we can use it to downsample the signal to a 200 KHz carrier. Normally, the signal at 162 MHz, and so quickly we can not sample, but at 200 KHz, we can sample the few seconds prime trucking at a time and then make different analyzes of the signal, "says Jens Dalsgaard prime trucking Nielsen.
"You can consider the AVR-based AIS receiver as our onboard reference receiver and SDR receiver as the experimental receiver, which - if all goes well - will deliver even better results," explains Jens Dalsgaard Nielsen. Launch in May
In Aalborg is an earth station to dismantle data and perform other communications with the satellite. It is possible to send up to 1 kW, if circumstances so require, explains Jens Dalsgaard prime trucking Nielsen, adding that it is usually interpreted AIS information that will be taken down.
"We can in principle also receive raw data at the university, but the bandwidth in the UHF band is quite limited, so we would prefer to avoid, however, we will of course try to get some raw samples down - which is a much sought after 'product'" says male.
AAUSAT3 also an attitude prime trucking control system, which is a detumbling system (AVR-based) and a pointing system (ARM7-based). Jens Dalsgaard Nielsen explains that the satellite also has a radio, a little unusual for cubesats using forward error corrective protocols. In addition, a log-AAUSAT3 and sw system and an intelligent power supply. Finally, there is almost a handful of microcontrollers that are internally connected via a Canbus network and using Aalborg University's open source cubesat space protocol (CSP - which can be found on google prime trucking code).
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