Suitability of the Site. The primary consideration in selecting a
site is its technical adequacy for meeting performance objectives. Generally,
these objectives are maximum signal-to-noise ratios at the receivers and
maximum effective power radiated in the desired direction from the
transmitters. Although other factors enter into selection of a site,
compromises for the sake of economy or logistic convenience must not interfere
with performance. The principal considerations for technical adequacy are
radio-frequency noise and topography, but suitability for construction at
reasonable cost, link requirements between components of the communication
station, land costs, and logistic support requirements are also considered.
Other factors are availability of utilities, climate, foundation stability,
survivability, physical security, and expansion potential.
Relationship to Design. The designer does not select the site, but
the considerations leading to its selection must be understood and
incorporated in the design. Before the designer begins work, the Field
Technical Authority of SPAWAR, in cooperation with the Engineering Field
Division of NAVFAC, conducts a site selection survey and an Electromagnetic
Compatibility (EMC) evaluation as part of the preparation of the BESEP.
Site Selection Survey. Considerations related to the
electromagnetic and physical environments that influence selection of a site
are listed in NAVELEX 0101,114, NAVELEX Calibration Program. A sample site
selection survey checklist is included in the appendix to that manual.
Electromagnetic Compatibility (EMC) Evaluation. Any factor that
prevents or degrades the reception of signals also degrades the ability of the
site to perform its mission. The receiving and direction-finding site should
be located where signal reception is known to be good. The EMC evaluation,
described in NAVELEX 0101,106, Electromagnetic Compatibility and
Electromagnetic Radiation Hazards, identifies environmental electromagnetic
interference from all sources, as well as radio noise. The EMC evaluation is
the responsibility of SPAWAR. All pertinent information will be set forth in
Isolation. Optimum radio communications depend largely on
isolation of the site from sources of interference and on proper dispersion of
structures within the site, Minimum separation distances for electromagnetic
interference protection of receiver sites are given in NAVELEX 0101,102, Naval
Communications Station Design, and in Table 1. Special separation
requirements for Naval Security Group (NAVSECGRU) receivers are given in
NAVELEX 0101,108, Naval Security Group Elements, Design and Performance.
Specific requirements for each project are developed in the BESEP; variations
required by local conditions are also established by the BESEP or by
authorized changes to it.