Patent ID: 7954375

Claim:
A system for measuring a gravitational acceleration, the system comprising: a trough constructed of an optically transmissive material, the trough comprising an axis, an inner surface and an outer surface, the inner surface having a V-shaped cross-section, the outer surface having a flat bottom portion, the trough configured to be positioned such that an angle between the axis and a horizontal plane is less than five degrees, thereby defining an inclined trough with an upper trough portion and a lower trough portion; a source of coherent light configured to direct coherent light to the flat bottom portion and thereby generate an evanescent field about the inner surface; a source of cold atom clouds configured release cold atom clouds at the upper trough portion; a Raman beam source configured to impart at least two quantum states on atom clouds within the trough; a sensor configured to measure a proportion of quantum states of atoms in cold atom clouds within the trough; a processor configured to receive a first signal reflecting the proportion and generate a second signal representing the gravitational acceleration; and an output for outputting data reflecting the gravitational acceleration.