Navigating more precisely with laser clocks

esa bulletin 122 - may 2005 53Navigating with Laser ClocksSpace-borne atomic frequency standardsare the backbone of today's advancedsatellite navigation and positioningsystems. Rubidium* gas-cell clocks constitutethe ideal frequency standard for this kind ofspace application, since they combine excellentshort- and medium-term stability with smallsize, as well as low weight and powerconsumption. The development of the keytechnologies, particularly in terms of reliablediode lasers and atomic vapour cells, will pavethe way towards low-power and miniature –ultimately chip-scale – atomic clocks forindustrial and domestic use.