Display aid for air traffic controllers, US4890232, 12/26/1989

The locations of aircraft on a first approach to a first runway are displayed on a line substantially parallel to a second approach to a second runway, the second runway converging with the first runway. The distances of aircraft on the first approach from a threshold of landing for the first runway are computed. These distances are used to draw a symbol of aircraft on the first approach onto the line parallel to the second approach at the distances from a threshold of landing for the second runway. The "mirror image" of aircraft displayed on the line parallel to the second approach will aid air traffic controllers in staggering aircraft approaching an airport on converging runways.

Low data rate communications link, US4856026, 08/08/1989

The data link includes a phase noise compensator to eliminate phase noise resulting from microwave frequency sources on a communications satellite. In addition, Fourier analyzers are utilized to determine the frequency of received signals having low carrier-to-noise density. The combination of the phase noise compensator and the Fourier analyzers permits data rates on the order of 50 to 400 bits per second to provide economically attractive communication links with aircraft over ocean areas.

Landmark hierarchy method for routing signals in a communications network, US4823111, 04/18/1989

A hierarchy of landmarks is established for the nodes in the network. Each node is assigned at least one hierarchy level designation and has a corresponding radius. An address is assigned to each of the nodes, the address including components representing landmarks wherein each landmark represented by the address component is within the radius of the landmark represented by the next lower address component. Each node maintains a routing table for routing entries to landmarks within the radii of which a node resides. A source node chooses a path toward the highest level landmark represented by the address components of a destination node until the path reaches a node within the radius of the landmark represented by the next lower level address component. This procedure is repeated for the remaining address components.

Low cost fiber optic network node, US4805234, 07/14/1989

The node includes plural optical receivers and transmitters. Each receiver and each transmitter of the node is connected to a user terminal by fiber optic cables. The output of each of the node receivers is electrically combined. Splitting logic is also included for splitting the electrical output of the receivers to serve as an input to the plural optical transmitters. The node may be used as an expansion mode or as a head-end unit. The optical receivers and transmitters have a low cost so that the overall node is approximately one fifth the cost of comparable nodes utilizing passive optical stars.