Abstract: A method and digital system for the compression and reconstruction of culal data for use with display systems, such as a system for producing a real time moving map display of terrain, provides a modified footprint/common boundary technique for data compression in which the footprint extends forward of the last point generated along a line in the direction of the line to that point. The particular scheme for compressed data reconstruction employs the storage of footprint data in such a manner that change in line direction information is automatically provided along with the necessary delta data information so that the direction of the line can be constantly updated as each point is generated. The compression of area cultural features involves a double compression of data based on a common boundary approach and the inner compression techniques of the modified footprint technique.

Abstract: A digital system for producing a real-time visual display in perspective of the terrain over which an aircraft is passing on the basis of compressed digital data stored on a cassette tape includes a perspective processor for transforming the addresses of points in a two-dimensional data pattern to the addresses these points occupy in a three-dimensional scene and for a filing in points between the transformed points to provide a complete display of the terrain in perspective.

Abstract: A fault detection and redundancy management system for a dual redundancy based network architecture in which the principal control components (master units) are configured and programmed to repetitively carry out intra- and inter-unit performance tests as an a priori requirement for network command capability. These performance tests are carried out in a prescribed sequence to define the fault detection and reconfiguration procedure. The procedure is designed to preclude the cascading of faults. As a first step in this procedure, each processor in a master unit performs a thorough self-test of its own functional capability. Secondly, if a processor has determined that it has passed all of these internal procedures, it must then successfully inform a designated "chief" processor via an interprocessor handshake. This interprocessor handshake is effected by causing each processor in the master unit to set a flag in a shared memory during a prescribed time interval.

Abstract: A method and digital system for the compression and reconstruction of cultural data for use with display systems, such as a system for producing a real time moving map display of terrain, provides a modified footprint/common boundary technique for data compression in which the footprint extends forward of the last point generated along a line in the direction of the line to that point. The particular scheme for compressed data reconstruction employs the storage of footprint data in such a manner that change in line direction information is automatically provided along with the necessary delta data information so that the direction of the line can be constantly updated as each point is generated. The compression of area cultural features involves a double compression of data based on a common boundary approach and the linear compression techniques of the modified footprint technique.

Abstract: A digital system for producing a real-time visual display in perspective of the terrain over which an aircraft is passing on the basis of compressed digital data stored on a cassette tape includes a perspective processor for transforming the addresses of points in a two-dimensional data pattern to the addresses these points occupy in a three-dimensional scene and for filling in points between the transformed points to provide a complete display of the terrain in perspective.