July 19, 2006 :: Spacewar.com :: News
Members of Cornell University’s Global Positioning System Laboratory have reportedly cracked the random number codes of Europe’s first global navigation satellite, despite efforts to keep the code secret. The navigational satellite, known as the Galileo In-Orbit Validation Element-A (GIOVE-A), is a prototype for 30 satellites that will constitute Galileo, a $4 billion joint venture of the European Union, European Space Agency, and private investors. Galileo, expected to be in service by 2010, is Europe’s answer to the U.S. GPS system. Yet while the GPS signal is free to consumers, Galileo is expected to charge a fee for its PRN (Pseudo Random Noise) codes, presumably in order to turn a profit for its investors. Since Galileo and GPS will share frequent bandwidths, Europe and the U.S. signed an agreement whereby some of Galileo’s PRN codes will be made public. Yet ever since GIOVE-A began broadcasting its first signals in January 2006, none of these codes have been released.
Enter Mark Psiaki, an aerospace engineer at Cornell and co-leader of the GPS Laboratory. In late January, Psiaki requested the PRN codes from Surrey Satellite Technology Ltd (SSTL), the small British company that built GIOVE-A. SSTL declined his request. Psiaki decided to obtain the codes himself “just with an antenna and lots of signal processing.” His team spent an entire week developing a basic algorithm, and two weeks later they received their first signal from the satellite. By mid-March they were able to derive their first estimates of the PRN code, and on April 1 the Cornell researchers published the final version on their website. On April 3, NovAtel Inc., a Canadian-based major manufacturer of GPS receivers, downloaded the codes from the website in a few minutes and soon afterward was able to begin tracking GIOVE-A for the first time. The PRN code and the methods used to extract it were published in the June issue of GPS World. (Article)
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