Accession Number : ADA191720

Title :   Optimization of the Dilation Characteristic on the Control Jurisdiction of an Area Control Facility.

Descriptive Note : Technical note,

Corporate Author : FEDERAL AVIATION ADMINISTRATION TECHNICAL CENTER ATLANTIC CITY NJ

Personal Author(s) : Mulholland, Robert G

PDF Url : ADA191720

Report Date : Jan 1988

Pagination or Media Count : 65

Abstract : In an air traffic control environment such as the National Airspace System the control function is based on stereographic representations of aircraft positions in a plane tangent to a sphere with a center collocated with the center of an ellipsoidal model of the geoid. The variation of the dilation (i.e., the discrepancy between the length of an infinitesimal arc on the model surface and the image of the arc in the plane) over the control jurisdiction of an air traffic control facility is one of many factors that adversely affect the ability of the facility to maintain separation standards. Techniques are disclosed for selecting a tangency point and a radius for the spherical support of the stereographic plane that minimize the variation of the dilation over the control jurisdiction about a predetermined constant. The constant can be viewed as a specification of the scale of the map that is the stereographic image in the plane of the portion of the surface of the earth model underlying controlled airspace.

Descriptors :   *AIR TRAFFIC CONTROL SYSTEMS, AIR SPACE, AIRCRAFT, CONTROL, CONTROL CENTERS, EARTH MODELS, ELLIPSOIDS, FACILITIES, FUNCTIONS, GEOIDS, IMAGES, MODELS, SEPARATION, SPHERES, STANDARDS, SURFACES, TANGENTS

Subject Categories : Air Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE