MSIModified surf index. A single dimensionless
number that is used to provide a relative measure of
conditions likely to be encountered in a surf zone
during amphibious operations.
MTFEditor-Message text format. The AUTODIN
message formatting software endorsed by the
MUFMaximum usable frequency.
NATONorth Atlantic Treaty Organization.
NAVAIDAn acronym for navigation aid, usually
referring to an aircraft navigation aid.,
Meteorology and Oceanography Command
headquartered at the Stennis Space Center,
Oceanographic Office, Stennis Space Center, MS.
NEXRADNext generation radar. The weather
surveillance radar-1988-Doppler (WSR-88D).
NIMANational Imagery and Mapping Agency,
headquartered in Washington, D.C.
NIPRNETNonsecure Internet protocol routing
network used by the military.
NITESNavy integrated tactical environmental
Administration, a division of the U.S. Department
o f C o m m e r c e .
NOTAMNotice to airmen.
OAAbbreviation for shipboard aviation operations
division, the shipboard division for which most
Aerographers Mates work.
OAMLOceanographic and atmospheric master
OMNI-DIRECTIONAL An antenna capable of
sending or receiving radio waves in all directions.
OTCIXSOfficer in tactical command information
PASSIVE USWA method for detecting submarines
that evaluates a signal received by a hydrophone.
PLAPlain language address used with AUTODIN
PSNProcessing sequence number used with
RADFOAn acronym for radiological fallout.
REFRACTIVITY The study of how elec-
tromagnetic energy is bent (refracted) as it moves
through different density layers within the
SARSearch and rescue.
SECRETClassified information that if disclosed
could cause serious damage to national security.
SERVERA fast computer connected to the Internet
full time. It directs Internet traffic to its proper
SHFSuper-high frequency radio waves. Generally
between 3 GHz and 30 GHz.
SIPRNETSecure Internet protocol routing network
used by the military.
SMOOSShipboard meteorological and ocea-
nographic observation system.
applied to messages requiring special handling
procedures. Special handling markings ensure
messages so marked will be handled and viewed by
authorized personnel only.
SSICStandard subject identification code.
STU-IIISecure telephone unit-third generation.
SYNOPTICIn general, pertaining to or affording an
overall view. In meteorology, this term has become
specialized in referring to the use of meteorological
data obtained simultaneously over a wide area for
presenting a comprehensive picture of the state of