Start Date
4-1969 8:00 AM
Description
It is the purpose of this paper to review the Navy's efforts in the field of Satellite Communications up to the present time, to indicate some of the problem areas, and to suggest some current and possible future trends. Most of the early Navy work in the 50 f s and early 60 f s involved use of "passive" satellites such as the moon, reflecting balloons and the like. The moon was used to bounce communications signals between places as far away as Washington and Hawaii. Since the early 1960's emphasis has steadily shifted to the use of "active" satellites which receive, amplify, and re-transmit signals, thus providing a much stronger signal at the receiver than the extremely faint signals reflected from the surface of the moon. As better boosters have become available, large and sophisticated satellites can be put into high altitude orbits. There is a strong trend toward "synchronous" orbits which cause the satellite to appear motionless over a point on the equator. From such a vantage point a satellite can see over 40% of the earth's surface.
Although much early work was done independently by the services, the present programs are, for the most part, joint efforts within the Department of Defense. The Navy's primary area of unique responsibility is in development of satellite communication terminals suitable for use aboard naval combatant type ships. Some difficult technical problems are involved such as finding suitable room for the antennas aboard crowded ships, electromagnetic interference with other systems, etc. Also, there are system problems to be worked out together with the other services such as best modulation methods, multiple access schemes, bandwidths and other important parameters. These problems are being solved. Satellite communications shows great promise of a major improvement in the Navy's vital long distance communications.
Satellite Communications in the Navy -A Look Back and A Look Forward
It is the purpose of this paper to review the Navy's efforts in the field of Satellite Communications up to the present time, to indicate some of the problem areas, and to suggest some current and possible future trends. Most of the early Navy work in the 50 f s and early 60 f s involved use of "passive" satellites such as the moon, reflecting balloons and the like. The moon was used to bounce communications signals between places as far away as Washington and Hawaii. Since the early 1960's emphasis has steadily shifted to the use of "active" satellites which receive, amplify, and re-transmit signals, thus providing a much stronger signal at the receiver than the extremely faint signals reflected from the surface of the moon. As better boosters have become available, large and sophisticated satellites can be put into high altitude orbits. There is a strong trend toward "synchronous" orbits which cause the satellite to appear motionless over a point on the equator. From such a vantage point a satellite can see over 40% of the earth's surface.
Although much early work was done independently by the services, the present programs are, for the most part, joint efforts within the Department of Defense. The Navy's primary area of unique responsibility is in development of satellite communication terminals suitable for use aboard naval combatant type ships. Some difficult technical problems are involved such as finding suitable room for the antennas aboard crowded ships, electromagnetic interference with other systems, etc. Also, there are system problems to be worked out together with the other services such as best modulation methods, multiple access schemes, bandwidths and other important parameters. These problems are being solved. Satellite communications shows great promise of a major improvement in the Navy's vital long distance communications.
Comments
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