RaviBg wrote:BrahMos to get GPS data from Russian satellites
During the failed test, the missile’s GPS system could not link its onboard computers with hovering satellites. This eventually crippled its guidance system, and the mission objectives were not achieved. The missile had apparently performed the flight plan but missed the target. It was fitted with an advance seeker which was to home in on the target using GPS data obtained through the US satellites.
BrahMos will now concentrate on the eight Glonass satellites, although they have a shorter range than the US spacecraft. “The necessary software modification has been incorporated to take care of the eventuality of not many satellites (eight is a small compared to the 24 US satellites) available for position updates,” BrahMos Aerospace CEO and MD, A Sivathanu Pillai told Deccan Herald on the sidelines of the ongoing “Aero-India 2009” airshow here.
Pl. see this snippet of various GPS systems from Strat...the US system is the best, so now the accuracy of Brahmos is degraded.
"The Major Players
This is because the U.S. Global Positioning System (GPS) is the world’s only fully-deployed and operational (and thus premier) satellite navigation system. It is being upgraded again, with the first next-generation GPS III satellites scheduled to be launched by 2013. GPS has been up and running the longest. Its first satellites were in orbit by the late 1970s, with full operational capability achieved in 1995 with 24 satellites transmitting navigational data. Today, around 30 satellites are generally operational as part of the constellation.
The newest GPS III will have much greater transmission power (reportedly on the order of 500 times that of the current system), which will make for a more robust signal much more resistant to jamming. Jamming is a very real concern for U.S. planners, as adversaries look for asymmetric means to challenge U.S. technological dominance on the battlefield. While the transmission of signals to and from space-based assets is a perennial weak spot for any space-faring nation, GPS III currently seems poised to stay ahead of that challenge — and will certainly be better prepared than any other alternative system to resist and overpower jamming.
Ivanov may have legitimate complaints about mishandling of GLONASS. But according to the Information-Analytical Center of Roscosmos, the Russian constellation currently has some 17 operational satellites (with an 18th in the process of being commissioned), all launched after the turn of the century. This is indeed nothing to scoff at, even if Roscosmos’ own internal definition of “operational” may be overly generous.
Ivanov’s complaint was more pointed at the integration of efforts in not only getting new satellites into orbit, but modernizing ground control centers and outfitting the Russian military and the civilian market with hand-held GLONASS navigational receivers.
But even with sufficient satellites in orbit and civilian receivers on the market, GLONASS will remain hindered by years of neglect. While its satellites are new, during the time GLONASS was experiencing years of neglect, the GPS was thriving as a military and civilian tool — years and utility that the U.S. military has learned a great deal from and integrated into its next generation systems. GLONASS also has comparatively little experience with handheld military — and especially civilian — navigational receivers. This has inflicted a very real handicap on the Russian system, even as it renews itself with new satellites.
China’s first satellite of the Compass system went up in 2000. There are currently five in orbit, with plans for 10 additional satellites to be added over the next two years and a total of 30 before 2015. At the moment, the five satellites provide limited regional navigational services to the mainland.
Of all GPS’ three competitors, the Chinese have the most ground to make up before it can compete qualitatively with GPS, meaning that the system will have significantly lower accuracy and will almost certainly be more susceptible to jamming.
Though Europe’s long-beleaguered Galileo continues to soldier on, it has largely died as a commercial endeavor because private funding on the order of US$3.3 billion never materialized for a service that would largely duplicate the already-free GPS service. Galileo has since received around US$4.5 billion in financing from the European Community budget, with collaboration between the European Commission and the European Space Agency. When all is said and done, its total estimated costs are expected to reach as high as US$12 billion.
Contracts to actually build the system are expected in the coming months.
Meanwhile, in 2004, the United States was able to outmaneuver France and keep the GPS military M-Code frequency separate from Galileo’s frequency. This has ensured that — at least hypothetically — GPS would be able to continue functioning on that frequency if Galileo’s frequency were jammed. Because GPS functions on both the M-Code and in the range of Galileo’s frequency, however, Galileo would not be able to function were GPS jammed.
In short, just as Russia is reconstituting GLONASS, China is pushing forward with Compass and Europe continues to struggle with the finer points of Galileo, GPS is poised to take another generational leap forward. And this leap is both in terms of military and civilian utility, ensuring that the world will continue to favor the U.S.-controlled system.
As the only fully functional global satellite navigation system, GPS continues to consolidate control of the civilian market. With all three alternatives at least a generation behind the curve (and possibly more), it will continue not only being free, but being the most competitive product on the market.
U.S. policy has long sought to coordinate “augmentation” of its GPS system, where other satellites can provide additional accuracy but work primarily in conjunction with the GPS system rather than separate from it. In addition to Galileo, the United States has had talks with Russia over GLONASS and discussed potential options with both Japan and India (both are beginning working on their own systems).
Given the superior capabilities of GPS, it is likely to remain a mainstay of NATO military operations even after Galileo comes online. And while the option for independent military operations free of reliance on GPS that a national satellite navigation system provides is indeed an attractive one, it comes at an enormous expense (billions of dollars), regular upkeep and will likely remain more vulnerable to interference than the more precise, robust and hardened GPS III.
But global precision-strike capability will become an increasingly important measure of military power in the years and decades to come, and satellite navigation has proven to be the most effective guidance for such capability. The continued development of satellite navigation alternatives to GPS thus will bear considerable watching from a military perspective, if not a commercial one. "