Method for issuing adaptive ground delays to air traffic, US5265023, 11/23/1993

A closed feedback system for issuing ground delays in air traffic control is disclosed, whereby the demand of arriving air traffic is constantly monitored and the ground delays are adjusted in real time to account for the demand that has not materialized. The departure messages from air traffic control centers are continuously monitored to determine if flights are departing on time. If a flight does not depart within a specified time interval, it is considered cancelled or delayed due to company reasons and the arrival slot is assigned to a flight that can use that slot. The slot vacated by the reassigned flight is assigned to another flight and so forth until all slots are filled. Provision is made for airlines to inform air traffic control of company delays and cancellations so that departure times can be assigned that the flight can meet. This scheme significantly improves the efficiency of operation and reduces the possibility of flights being given ground delays when the capacity at the airport is not fully utilized.

Optically neutral laser shield, US5208698, 05/04/1993

An optical device that is optically neutral to normal light but absorbs highly collimated light is formed as a mosaic of optical cells. Each cell has at least two refracting surfaces and a non linear material at a focus internal to those surfaces. In one form, the cell comprises two pairs of lenses with a layer of non-linear light absorbent material interposed between the lenses of each pair. The lens elements can be one-power telescopes. A first lens element focuses highly collimated light at its entrance aperture on the non-linear layer. The intensity of the focused light causes the non-linear layer to become opaque or reflective and thereby reduce, or substantially block, the transmission of highly collimated light. The second pair of lenses inverts the re-collimated light exiting the first lens pair. By arranging the optical cells in an array, it is possible to obtain a coherence of the light diffracted from individual cells to produce a wave front from the mosaic as a whole having a resolution that is superior to that of the cells.