XNAV - это реально?

[Agent]

Или один из ДАРПовских задвигов? Самый опасный в мире остров как вариант.

Military Eyes Pulsar Navigation Network

The Defense Advanced Research Projects Agency (DARPA) is delving into creation of a "Pulsar Network" for satellites to know their exact whereabouts in space and time.

The idea is to create a celestial seasoning of sorts, adding a little pizzazz to the Global Positioning System (GPS) constellation of satellites in Earth orbit.

"We're on our way...basically creating a pulsar network," said Tony Tether, Director of DARPA during opening remarks at the Small Satellites: Complimentary or Disruptive Technology conference, being held this week at Utah State University.

The effort is dubbed X-ray Source-based Navigation for Autonomous Position Determination (XNAV) Program, and is being spearheaded under DARPA's tactical technology work, Tether told the audience.

XNAV is a research and development look into an autonomous position, attitude and time determination system using celestial sources in the X-ray band of the electromagnetic spectrum. The goal of this program is to prove the feasibility and viability of the use of celestial sources, pulsars as well as neutron stars for position, attitude and time determination of low Earth orbiting spacecraft.

Such a capability would provide an autonomous backup system to military navigation and communication satellites. Using XNAV, a satellite in space will be able to find where it is using pulsars.

In the GPS world there's a term called "Dilution of precision" - a measure of the quality of the GPS data being received from the satellites. "I don't think we'll have that problem with pulsars," Tether said. "First of all, there's lots of pulsars," Tether said. "What hasn't been done is that they haven't been characterized. It would be useful for anywhere in the solar system...a great way to navigate around, all over space."