Map projections for satellite tracking.

New map projections to be used for plotting successive satellite groundtracks show these tracks as straight lines. The map may be made conformal along any 2 parallels of latitude between the limits of latitude reached by the groundtrack, or the 'tracking limits'. If these parallels are equidistant from the Equator, they may both be made true to scale, and a cylindrical projection results. If these parallels are not equidistant from the Equator, only one may be made true to scale, and a conic projection results. The groundtracks generally have sharp breaks at either tracking limit. If the tracking limit is one of the parallels at which the map is conformal, there is no break in the groundtrack, and the conic projection may approach (but cannot become) an azimuthal projection.-Author