3-cm                                         3-centimeter wavelength, approximately 9.4 GHz

10-cm                                       10-centimeter wavelength, approximately 3.0 GHz

ARPA                                       Automatic Radar Plotting Aid

ATA                                          Automatic Tracking Aid

BW                                           Beamwidth

CBD                                          Chesapeake Bay Detachment (of the Naval Research Laboratory)

dB                                            decibels

dBd                                          Antenna Gain (dB) compared with dipole antenna

dBi                                           Antenna Gain (dB) compared with isotropic antenna

dBmW                                      Milliwatts in decibel form

dBW                                         Watts in decibel form

DC                                            Duty Cycle, also Direct Current

ECDIS                                       Electronic Chart Display and Information System

EIRP                                         Equivalent Isotropic Radiated Power

ENC                                          Electronic Nautical Chart

EPA                                          Electronic Plotting Aid

ERP                                          Effective Radiated Power

FCC                                          Federal Communications Commission

GHz                                          Gigahertz, 1* 109 Hz

GPS                                          Global Positioning System

H/V                                           Horizontal/Vertical

HBW                                         Horizontal beamwidth

HSC                                          High Speed Craft (an IMO designation)

Hz                                             Hertz

IALA                                          International Association of Marine Aids to Navigation and Lighthouse Authorities

ICAO                                         International Civil Aeronautical Organization

IEC                                            International Electrotechnical Committee

IFM                                           Instantaneous Frequency Measurement

IMO                                           International Maritime Organization

ITU                                            International Telecommunications Union

kW                                            kilowatt(s)

LCD                                          Liquid Crystal Display

MARPA                                     Mini-ARPA

MHz                                          Megahertz, 1*106 Hz

MNR(s)                                      Marine Navigation Radar(s)

mW                                           milliwatts

NMEA                                       National Marine Electronics Association

NRL                                          United States Naval Research Laboratory

PD                                            Pulse Duration

PI                                              Pulse Interval

PPI                                            Plan-position Indicator

PRF                                           Pulse Repetition Frequency

PRI                                            Pulse Repetition Interval

RADAR                                      Radio Aid to Detection And Ranging

Range-base                                Greatest Common Denominator for all mode-specific inter-pulse intervals

RF                                             Radio Frequency

RPM                                          Revolutions Per Minute

SOLAS                                      Safety Of Life At Sea

VBW                                         Vertical beamwidth

VDU                                          Visual Display Unit

VHF                                          Very High Frequency (defined by ITU as 30-300 MHz)