Emerging Technology from the arXiv

A View from Emerging Technology from the arXiv

How to Use Pulsars for Interstellar Navigation

The signals from pulsars form a natural GPS system that could locate any object in the galaxy to within a meter.

  • May 27, 2009

The Global Position System has revolutionised navigation on Earth. It consists of a network of satellites that each broadcast a time signal. A receiver on Earth can then work out its position in three-dimensional space by comparing the arrival times of the signals from at least three satellites. But the system cannot help with navigation on an interplanetary scale or beyond.

Today, Bertolomé Coll at the Observatoire de Paris in France and a friend, Albert Tarantola, propose an interstellar GPS system that has the ability to determine the position of any point in the galaxy to within a metre.

Their idea is to tune in to the signals from four pulsars: 0751+1807 (3.5ms), 2322+2057 (4.8ms), 0711-6830 (5.5ms) and 1518+0205B (7.9ms), which each generate regular millisecond radio signals.

These form a rough tetrahedron centred on the Solar System.

Why four pulsars? Coll points out that on these scales relativity has to be taken into account when processing the signals and to do this, the protocol has to specify a position in space-time, which requires four signals.

Coll then defines the origin for this system of co-ordinates as 00:00 on 1 January 2001 at the focal point of the Interplanetary Scintillation Array, the radio telescope near Cambridge in the UK that first observed pulsars.

With the co-ordinate system established, any interplanetary spacecraft could then use the signals from these pulsars to determine its position in this co-ordinate system to within a few nanoseconds, which corresponds to about a metre.

Handy, and cheap too.

Ref: http://arxiv.org/abs/0905.4121: Using Pulsars to Define Space-Time Coordinates

Tech Obsessive?
Become an Insider to get the story behind the story — and before anyone else.
Subscribe today

Uh oh–you've read all five of your free articles for this month.

Insider Premium

$179.95/yr US PRICE

Want more award-winning journalism? Subscribe to Insider Plus.

  • Insider Plus {! insider.prices.plus !}*

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus ad-free web experience, select discounts to partner offerings and MIT Technology Review events

    See details+

    What's Included

    Bimonthly home delivery and unlimited 24/7 access to MIT Technology Review’s website.

    The Download. Our daily newsletter of what's important in technology and innovation.

    Access to the Magazine archive. Over 24,000 articles going back to 1899 at your fingertips.

    Special Discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

You've read of free articles this month.