Combining the use of geostationary and inclined orbit satellites for integrated communications and navigation applications

The diversity of requirements for mobile communications and position determination suggests a liberal interpretation of `integration´ of communications and navigation. The authors propose that a combination of INMARSAT geostationary and GPS inclined-orbit satellites could be employed in a hybrid mode so as to obtain most of the advantages of both passive navigation and active radiolocation (surveillance). The application of this concept to oceanic air traffic control is used to illustrate how such integration enhances both the communications and navigation functions