VOLUME I Multinational Maritime Tactical Instructions and Procedures

SECTION II — TACTICAL ASPECTS OF SATELLITE COMMUNICATIONS (SATCOM)
4200 INTRODUCTION
Satellites provide a method of line-of-sight communications over long distances. They have the
advantage of being little affected by ionospheric phenomena and thereby offer high availability and
reliability. SATCOM is limited in range only by the requirement for both shore and ship terminals to be
within the earth coverage of the satellite antenna, and communication links via satellite have therefore
assumed a most significant role in communication between the OTC afloat and commander ashore.
4201 SYSTEMS
Technical details and procedural instructions for use of SATCOM are given in national
publications, which may be released to other nations, as required. A number of commercial systems are
available for use by the merchant fleets of the world. These provide telephone and telex facilities and may
be used with appropriate off-line encryption to carry tactical traffic to suitably equipped auxiliaries.
4202 EMPLOYMENT
Military SATCOM systems generally provide secure transmissions and reception facilities for
telegraph, voice, and data traffic. They may be provided for strategic or tactical use.
a. Strategic Use. Because of their excellent long-distance performance, the majority of
SATCOM channels are used for strategic purposes between maritime forces and shore-based authorities.
Where traffic to and from a seaborne commander is heavy, satellite communications channels may be
configured as maritime rear link or full period terminations.
b. Tactical Use. Certain SATCOM systems are configured for tactical exchange of voice or data.
Where such a requirement is identified for strategic systems, this can be achieved, with the concurrence of
the operating authorities concerned, by transmission of traffic via shore for automatic retransmission over
satellite broadcast or rear link. This procedure may also be used for the radiation of a TF/TG broadcast
using shore-based transmitters, but the technique is expensive in satellite capacity and should be used
sparingly.
4203 ELECTRONIC WARFARE (EW) CONSIDERATIONS
MTP 1(D), Vol. I
a. Security. By virtue of the highly directional nature of satellite transmissions from the mobile
terminal, and the narrow beamwidth employed by them, SATCOM systems are less susceptible to D/F
than are HF transmissions. Nonetheless, they employ high power, generate significant sidelobes, and,
particularly at low angles of elevation, may be detected by enemy ESM at long ranges.
b. Effect on Friendly ESM. Because of the frequencies at which they operate, satellite
transmissions may affect the sensitivity of friendly ESM equipments. This factor, and the susceptibility of
SATCOM to intercept and D/F, must be considered when the emission policy is formulated.
c. ECM. Most SATCOM systems are vulnerable to ECM. Where SATCOM provides a primary
communications route, consideration should be given to the provision of alternative means of transmission
as a backup.
d. Limitations. When operating in high latitudes, continuous SATCOM is not possible because
of coverage limitations from geosynchronous orbits.
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