An interplanetary GPS using pulsar signals
May 24, 2013
Researchers have worked out the practical details for an autonomous spacecraft navigation system using signals from pulsars in essentially the same way that we use GPS satellites to navigate on Earth, MIT Technology Review reports.
A pulsar is a rotating neutron star that emits a beam of electromagnetic radiation at a very precise interval between pulses that ranges from milliseconds to seconds.
By measuring the arrival time of pulses from at least three different pulsars and comparing this with their predicted arrival time, it is possible to work out a position in three-dimensional space.
The researchers at the Max Planck Institute for Radio Astronomy in Germany say that technology being developed now would allow spacecraft to work out their position to within five kilometers anywhere in the solar system.
The researchers calculate that for 21-centimeter waves, the spacecraft would require an antenna with a collecting area of 150 square meters.
But a better idea, they say, is to use pulsars that emit x-rays, since the technology for collecting and focusing x-rays has improved dramatically in recent years.