A

ACSM

American Congress on Surveying and Mapping

A/D

Analog To Digital

ADF

Automatic Direction Finder

ADIU

Advanced Digital Interface Unit

ADS

Automatic Dependent Surveillance

AEEC

Airlines Electronics Engineering Committee

AFB

Air Force Base

AJ

Antijamming

AM

Amplitude Modulation

AM/FM

Automated Mapping and Facilities Management

AMPS

Advanced Mobile Phone Service

AOPA

Aircraft Owners And Pilots Association

APA

Airline Pilots Association

ARINC

Aeronautical Radio Inc.

AS

Anti-spoofing

ASF

Additional Secondary Factor (Loran-C)

ASPRS

American Society of Photogrammetry and Remote Sensing

ATA

Air Transport Association

ATC

Air Traffic Control

ATON

Aids To Navigation

AVL

Automatic Vehicle Location

AVLN

Automatic Vehicle Location And Navigation

AVM

Automatic Vehicle Monitoring

B

BPSK

Binary Phase Shift Keying

BBS

Bulletin Board Service

C

C/A

Course Acquisition

CAD

Computer Aided Design

CCW

Coded Continuous Wave

CCZ

Coastal And Confluence Zone

CDMA

Code Division Multiple Access

CEP

Circle Error Probable

CMOS

Complementary Metal Oxide Semiconductor

CNES

Centre National d'Etudes Spatiale

CNS

Communications, Navigation, And Surveillance

COG

Course Over Ground

COP

Circle Of Position

CONUS

Continental United States

CORS

Continuously Operating Reference Station

CS

Control Segment

CW

Continuous Wave

D

D/A

Digital To Analog

DCW

Digital Chart of the World

DEM

Digital Elevation Model

DLG

Digital Line Graph

DGPS

Differential Global Positioning System

DLL

Delay Lock Loop

DMA

Defense Mapping Agency

DME

Distance Measuring Equipment

DoD

Department Of Defense

DOP

Dilution Of Precision

DOQ

Digital Ortho Quadrangle

DOQQ

Digital Ortho Quarter Quadrangle

DRG

Digital Raster Graphic

DoT

Department Of Transportation

DR

Dead Reckoning

DRMS

Distance Root Mean Square

DTM

Digital Terrain Model

E

ECDIS

Electronic Chart Display And Information System

ECEF

Earth Centered, Earth Fixed

EDM

Electronic Distance Measurement

EGNOS

European Geostationary Navigation Overlay Service

EOS

Earth Orbiting System

EPROM

Erasable Programmable Read-Only Memory

EHF

Extremely High Frequency

ESRI

Environmental System Research Institute

ETA

Estimated Time Of Arrival

F

FAA

Federal Aviation Administration

FANS

Future Air Navigation Systems

FCC

Federal Communications Commission

FDMA

Frequency Division Multiple Access

FM

Frequency Modulation

FMS

Flight Management Systems

FOC

Full Operational Capability

FRP

Federal Radionavigation Plan

FTRP

Framework Transportation segment Reference Point

G

GCDB

Government Corners Data Base

GDOP

Geometric Dilution Of Precision

GIAC

GPS Interagency Advisory Council

GIC

GPS Integrity Channel

GIS

Geographic Information Systems

GLONASS

Global Navigation Satellite System

GMT

Greenwich Mean Time

GNIS

Geographic Names Information System

GNSS

Global Navigation Satellite Systems

GPS

Global Positioning System

GPSIC

GPS Information Center

H

HDOP

Horizontal Dilution Of Precision

HF

High Frequency

HHA

Harbor And Harbor Approach

HOPE

H-II Orbiting Plane (Japan)

HOW

Hand Over Word

HTML

Hyper Text Markup Language

Hz

Hertz

I

IALA

International Association Of Lighthouse Authorities

ICAO

International Civil Aviation Organization

ICD

Interim Control Segment

ICS

Interim Control Segment

IEEE

Institute Of Electrical And Electronics Engineers

IERS

International Earth Rotation Service

IFR

Instrument Flight Rules

IF

Intermediate Frequency

IGEB

Interagency GPS Executive Board

IGS

International GPS Service

ILS

Instrument Landing System

IMO

International Maritime Organization

IMU

Inertial Measurement Unit

INS

Inertial Navigation System

IOC

Initial Operational Capability

ION

Institute Of Navigation

IRU

Inertial Reference Unit

ITRF

International Terrestrial Reference Frame

ITU

International Telecommunication Union

IVHS

Intelligent Vehicle Highway Systems

J

JPL

Jet Propulsion Laboratory

JPO

Joint Program Off

K

KHz

Kilohertz

L

L1

GPS Carrier Frequency, 1575.42 MHz

L2

Carrier Frequency, 1227.6 MHz

LAAS

Local Area Augmentation System

LAN

Local Area Network

Lat

Latitude

Lat/Lon

Latitude/Longitude

LCD

Liquid Crystal Display

LED

Light Emitting Diode

LEO

Low Earth Orbit

LIDAR

Light Detection And Ranging

LIS

Land Information System

LF

Low Frequency

Lon

Longitude

LOP

Line Of Position

Loran Long-Range Navigation

A land-based radio navigation system operated by the U.S. Coast Guard as a public service.

Loran-C

The current version of Loran in common use, which operates in the low-frequency 90 to 110 kHz band.

LOS

Line Of Sight

M

MCS

Master Control Station

MEP

Midcontinent Expansion Plan

MF

Medium Frequency

MGRS

Military Grid Reference System

MHz

Megahertz

MOPS

Minimum Operational Performance Standards

MSAS

MTSAT's Augmentation System

MSK

Minimum Shift Keying

MSS

Mobile Satellite Service

MTSAT

Multifunction Transport Satellite

N

NAD

North American Datum

NANU

Notice Of Advisory To Navstar Users

NAS

National Airspace System

NASA

National Aeronautics And Space Administration

NAV-Msg

Navigation Message

NavStar GPS

Navigation Satellite Timing And Ranging Global Positioning System

NAVWAR

Navigation and Warfare

NDB

Nondirectional Beacon

NDOP

National Digital Orthophoto Program

NGS

National Geodetic Survey

NIMA

National Imaging and Mapping Agency

NIST

National Institute of Standards And Technology

Nm

Nautical Mile

NMEA

National Marine Electronics Association

NNSS

Navy Navigation Satellite System (Transit)

NOAA

National Oceanic And Atmospheric Administration

NOCUS

North Central U.S. Chain (Loran-C)

NOS

National Ocean Survey

NRL

Naval Research Laboratory

Ns

Nanosecond

NSGIC

National States Geographic Information Council

O

OAB

Operational Advisory Broadcasts

OCS

Operational Control Segment/System

OCXO

Oven-Controlled Crystal Oscillator

OEM

Original Equipment Manufacturer

P

P-Code

Precision/Protected Code

PC

Personal Computer

PCS

Personal Communication System

PDOP

Position Dilution Of Precision

PLL

Phase-Locked Loop

PLS

Public Land Survey

PLSS

Public Land Survey System

PNT

Positioning, Navigation, and Timing

PPM

Parts Per Million

PPS

Precise Positioning Service

PPS

Pulse Per Second

PRISM

Parameter-elevation Regressions on Independent Slopes Model

PSAP

Public Service Answering Point

PR

Pseudorange

PRN

Pseudo Random Noise

PVT

Position Velocity and Time

R

RAWS

Remote Automated Weather Station

R&D

Research And Development

RAIM

Receiver Autonomous Integrity Monitoring

RDF

Radio Direction Finder

RDS

Radio Data System

RDSS

Radio Determination Satellite Systems

RF

Radio Frequency

RFI

Radio Frequency Interference

RINEX

Receiver Independent Exchange (Format)

RMS

Root Mean Square

ROV

Remotely Operated Vehicle

RTI

Road Transport Informatics

RTCA

Radio Technical Commission For Aeronau

RTCA-SC

Radio Technical Commission for Aeronautics, Special Committee

RTCM

Radio Technical Commission For Maritime S

RTK

Real-Time Kinematic

S

SA

Selective Availability

SAR

Search And Rescue

SAR

Syntheticaperture Radar

Sat Nav

Satellite Navigation (Transit System)

SCAT I

I Special Category I

SDE

Spatial Database Engine

SDSFIE

Spatial Data Facilities, Infrastructure, and Environment

SDTS

Spatial Data Transfer Standard

SEP

Sphere Error Probable

SGML

Standard Generalized Markup Language

SHF

Super High Frequency

SLR

Satellite Laser Ranging

SNR

Signal To Noise Ratio

SOA

Speed Of Advance

SOCUS

South Central U.S. Chain (Loran-C)

SOG

Speed Over Ground

SOIT

Satellite Operational Implementation Team

SPS

Standard Positioning Service

SV

Space Vehicle

SVN

Space Vehicle Number

T

TACAN

Tactical Air Navigation

TAI

International Atomic Time

TCXO

Temperature-Controlled Crystal Oscillator

TD

Time Difference

TDMA

Time Division Multiple Access

TDOP

Time Dilution Of Precision

TIGER

Topologically Integrated Geographic Encoding and Reference

TIN

Triangular Irregular Network

TOA

Time Of Arrival

TOD

Time Of Day

TOPEX

The Ocean Topography Experiment

TOW

Time Of Week

TSO

Technical Standard Order

TSPI

Time And Space Position Information

TTL

Transistor Transistor Logic

TVC

Tagged Vector Contours

U

UAV

Unmanned Aerial Vehicle

UE

User Equipment

UEE

User Equipment Error

UERE

User Equivalent Range Error

UHF

Ultra High Frequency

URA

User Range Accuracy

URE

User Range Error

US

User Segment

USAF

United States Air Force

USCG

United States Coast Guard

USGIC

US GPS Industry Council

USGS

US Geological Survey

USNO

US Naval Observatory

UT

Universal Time

UTC

Coordinated Universal Time

UTM

Universal Transverse Mercator

V

VDOP

Vertical Dilution Of Precision

VFR

Visual Flight Rules

VGA

Video Graphics Array

VHF

Very High Frequency

VLBI

Very Long Baseline Interferometry

VLF

Very Low Frequency

VLM

Vehicle Location Monitoring

VME

Versa Module Eurocard

VOR

Very high frequency Omnidirectional Range

VORTAC

VOR and TACAN (collocated)

VPF

Vector Product Format

VSWR

Voltage Standing Wave Ratio

VTC

Vessel Traffic Center

VTS

Vessel Traffic Services

W

WAAS

Wide Area Augmentation System

WADGPS

Wide Area Differential Global Positioning System

WAN

Wide-Area Network

WGS

World Geodetic System

WGS 84

World Geodetic System of 1984

WRC

World Radio Conference