Abstract: In some variations, an interferometric frequency-reference apparatus comprises: an atom source configured to supply neutral atoms; a collimator configured to form a collimated beam of the neutral atoms; one or more probe lasers; and a Doppler laser configured to determine a ground-state population of the neutral atoms. Other variations provide a method of creating a stable frequency reference, comprising: forming a collimated beam of neutral atoms; illuminating the neutral atoms with first and second probe lasers; adjusting the frequencies of the first probe laser and second probe laser using Ramsey spectroscopy to an S?D transition of the neutral atoms; and determining a ground-state population of the neutral atoms with another laser. The interferometric frequency-reference apparatus may provide an optical frequency reference or a microwave frequency reference.

Abstract: A stabilization system or gimbal having a mounting arrangement (3) for a camera providing for rotation about pan, roll, and tilt axes (210, 230, 220) where tilt and roll axis (220, 230) position can be independently adjusted is described. The arrangement can be configured so that when adjusting the stabilization frame relative to the roll axis, adjustment of the camera COG relative to the tilt axis is inhibited. The system can further be arranged such that when adjusting the roll axis, adjustment relative to the tilt axis is inhibited. Similarly, when adjusting the pan axis, adjustment to the tilt or roll axes may be inhibited.

Abstract: A stabilization system or gimbal having a mounting arrangement (3) for a camera providing for rotation about pan, roll, and tilt axes (210, 230, 220) where tilt and roll axis (220, 230) position can be independently adjusted is described. The arrangement can be configured so that when adjusting the stabilization frame relative to the roll axis, adjustment of the camera COG relative to the tilt axis is inhibited. The system can further be arranged such that when adjusting the roll axis, adjustment relative to the tilt axis is inhibited. Similarly, when adjusting the pan axis, adjustment to the tilt or roll axes may be inhibited.

Abstract: Computers are linked together to form a network. Messages are sent over the links between the computers in compressed, segmented form, the size of the segments being appropriate to the transmission characteristics of the link. A message previously received or transmitted by a computer is stored in compressed and segmented form. If it is desired to forward or re-transmit this message, the segment size of the stored form is compared against the optimum segment size for the link over which the message is to be sent. If there is a close match, then the stored segmented, compressed message is retrieved for direct transmittal, without having to resegment or recompress the message.