PulsarPlane: a feasibility study for millisecond radio pulsar navigation

Stars have been used -in what is called celestial navigation- since thousands of years by mankind. Celestial navigation was used extensively in aviation until the 1960s, and in marine navigation until recently. It has been investigated for agriculture applications, utilized for military aircraft and, presumably, for intercontinental ballistic missiles. Recently the interest in celestial navigation has sparked again with an emphasis on deep space navigation using pulsars. Pulsars are fast rotating neutron stars that emit electromagnetic radiation, which is received anywhere in our solar system as a series of very stable fast periodic pulses. A number of studies have been performed on navigating using pulsar signals; the first study performed by NASA in 1974 focused on radio pulsars, but in later years most attention was given to X-ray pulsars. Radio pulsar navigation - utilizing signals which could be detected on Earth - has not received much attention, since the signal strength of radio pulsars was deemed too weak to be useful. Advances in signal processing, analog/RF circuit design as well as antenna design, however, could enable faster and more accurate detection of pulsar signals, using a smaller antenna size. The objective of this paper is to investigate the feasibility of a navigation system inside the Earth's atmosphere using signals from millisecond radio pulsars. The study is part of the research project PulsarPlane under the European 7th Framework Programme as a pioneering idea, i.e. technologies and concepts that have the potential to bring step changes in the second half of this century and beyond.