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AFE: Atlas Florae Europaeae. The AFE grid is modified from the Military Grid Reference System (MGRS). The MGRS itself is an alphanumeric version of a numerical UTM (Universal Transverse Mercator) or UPS (Universal Polar Stereographic) grid coordinate. Antarctic Circle: An imaginary circle on the surface of the earth at 66.5°S lat.or 23.5° north of the South Pole. It marks the southernmost point at which the sun can be seen at the winter solstice (about June 22) and the northernmost point of the southern polar regions at which the midnight sun is visible.
. Arctic Circle: An imaginary circle on the surface of the earth at 66.5°N latitude, or, 23.5° south of the North Pole. It marks the northernmost point at which the sun can be seen at the winter solstice (about Dec. 22) and the southernmost point of the northern polar regions at which the midnight sun is visible.. BIPM: Bureau International des Poids et Mesure.The international bureau of weights and measurements, in Paris. Responsible for the UTC time scale. BNC: Bayonet N Connector. A common type of antenna connector. Push and Turn to lock BRG: Bearing. The direction to the To waypoint. CDMA: Code Division Multile Access. a technology where different radio's can work on the same frequency. GPS uses it. CODE PHASE GPS: GPS measurements based on pseudo random code (C/A or P) as opposed to carrier
of that code. C Code: The less accurate Civilian GPS Signal. See SA. COG: Course Over Ground, Your current direction of travel relative to a ground position (same as Track). CONUS: Continental United States. An Abbreviation used in a class of Datums. CTS: Course To Steer. CMG: Course Made Good. How you are progressing towards your next waypoint. Datum: Map Datum's are the reference system used between the Lat/Longs and the map being used as a reference. There are hundreds of them, and you have to tell your GPS unit which one to use. This site, Garmin and Delorme default to WGS84. Dead Reckoning: A very simple method of using time and distance to navigate. Deviation: Errors from your course. Either built in or unintentional.One type of deviation is Magnetic, the difference between a true course and what a compass will tell you. DGPS: Differential GPS. A local transmitter is used for greater accuracy. DBR: Differential Beacon Receiver. Differential Beacon Receivers tune to the United States Coast Guard's high differential correction beacon stations for improved position accuracy. RTCM 104 input signal is supplied to a DGPS unit to correct for SA and Atmospheric errors. The operating frequency range is 285 kilohertz to 325 kilohertz Dithering: The introduction of digital noise. This is the process the DOD uses to add inaccuracy to GPS signals
to induce Selective Availability (SA) DMA: Defence Mapping Agency. DOP: Dilution of Precision, errors caused by bad geometry of the Satellites. DTK: Desired Track. The course between To and From. EGNOS: The European WAAS. EPE: Estimated Position Error. How much the unit thinks it is off target. Equator: Zero degrees Latitude. A line around the center of earth 24,901.55 miles (40,075.16 kilometers) long. ETA: Estimated Time of Arrival. ETE: Estimated Time Enroute. FGDC: The Federal Geographic Data Committee (FGDC) is an interagency committee, organized in 1990 under OMB Circular A-16 that promotes the coordinated use, sharing, and dissemination of geospatial data on a national basis. The FGDC is composed of representatives from nineteen Cabinet level and independent federal agencies. The Steering Committee sets high-level strategic direction for the FGDC as a whole. The Coordination Group advises on the day-to day business of the FGDC. Staff support for FGDC committees is provided by the FGDC Secretariat staff. Fix: A position that is Determined by the navigation unit. FUBAR: Fouled Up Beyond All Repair. Galileo: Europe's GPS system.May be operational by 2008. GANS: The Air Force's Global Access, Navigation, and Safety (GANS) program. Geocaching:The sport where you are the search engine, and you have to hunt for treasure caches with your GPS . GDOP: Geometric Dilution of Precision, see DOP.
GDOP Components
PDOP = Position Dilution of Precision (3-D), sometimes the Spherical DOP.
HDOP = Horizontal Dilution of Precision (Latitude, Longitude).
VDOP = Vertical Dilution of Precision (Height).
TDOP = Time Dilution of Precision (Time). Getting: Ivan A. Getting, Father of the GPS system born 1912. Bradford Parkinson worked on the implemented the system. GLONASS: The Russian equivalent to the NAVSTAR GPS. GMT: Greenwich Mean Time or UT1 (Universal TIme One) ]) is a time scale tied to the rotation of the Earth in respect to the fictitious 'mean Sun'. UTC is, however, kept within 0.9 seconds of UT1, by virtue of leap seconds. GPS: Global Positioning System. Usually refers to the USA's NAVSTAR system. Great Circle Route A great circle is defined as a circle on the earth's surface the plane of which passes through the center of the earth.
For navigation purposes :
The great circle track is the shortest distance between two places on the earth's surface.
The great circle track appears as a straight line on Gnomonic (great circle) charts.
The vertices of a great circle are the two points nearest to the poles which have a course on the great circle track due EAST / WEST.
see also Rhumb Line GS: Ground Speed. GWEN: Air Force Ground Wave Emergency Network Illumination: The signal coming from the GPS Satellites. Isogonic Lines: A line on a map or chart where the magnetic deviation is the same. ITU: International Telecommunication Union JPALS: Joint Precision Approach and Landing System, is a DGPS system pro rapid deployment. Uses WAAS/LAAS LAAS: Local Area Augmentation System. LDGPS: Local Differential GPS. Two or more GPS Receivers are used to create a local reference to each other. Magnetic North: The direction to the Magnetic North Pole. It is what a magnetic compass indicates. It is different from True North, by the value of the Mag. Var. Mag. Var.: Magnetic Variation. the different between true North (pointing towards the Geographic Pole) and Magnetic North (pointing towards Magnetic Pole) where a compass points to. Tthe magnetic variation of the earth changes at a rate of 50.27 seconds of arc per year. Memory trick, East is Least and West is Best ( you subtract East variations and Add West variations) Map Datum: What reference map is used in determining the Fixes. Map Projections: Most people don't think the world is flat anymore, but paper and parchment maps are. To correct for this, a curved surface has to be "projected" onto a flat surface (the map paper). Mercator, Orthographic and Conic are common types of projections. MCX: Antenna connector used on some of the newer GPS units. MGRS: Military Grid Reference System. The MGRS is an alphanumeric version of a numerical UTM (Universal Transverse Mercator) or UPS (Universal Polar Stereographic) grid coordinate MOB: Man Over Board. A button to take an immediate fix, so you can find a lost person. MOPS: Minimum Operational Performance Standards. MSAS: The Japanese WAAS. NANU's: NOTICE ADVISORY TO NAVSTAR USERS (Latest NANUs). NAD27: North American Datum 1927. It is broken down into different areas, from Central America to Greenland. Yes I know Central America is not in North America, but I don't make this stuff up. NAD27 CONUS: North American Datum 1927, Mean Value NDGPS: Nationwide Differential GPS, The NDGPS plan calls for the conversion of a number of U.S. Air Force Ground Wave Emergency Network (GWEN) sites to broadcast DGPS signal. The range is 250 miles. NEMA: National Electrical Manufacturers Association NEMA 0183: A communication protocol used by GPS units and other types of navigation and marine electronics. NIMA: National Imaging and Mapping Agency. NSDI: National Spatial Data Infrastructure. NSTB: FAA's National Satellite Test Bed. NTSB: National Transportation Safety Board. OSM: Ordnance Survey Maps. Britain's National Mapping Agency OziExplorer: Scanned map software for use with GPS. P Code: Precision Code. The more accurate GPS signal. Prime Meridian:The zero longitude location from where east and west is measured. It passes through Greenwich, England. Pseudolite: An Extra Satellites like device, installed on the ground in the local area. It is used to supply "illumination" and correction signals for DGPS systems. RAIM: Receiver Autonomous Integrity Monitoring (detection of erroneous satnav data via comparing multiple navigation solutions). Rhumb Line: A line that passes through all meridians at the same angle. When drawn on a Mercator chart, the rhumb line is a straight line, because the Mercator chart is a distortion of a spherical globe on a flat surface. The rhumb line results in a longer course than a great circle route.
See also Great Circle Route RNP: Required Navigation Performance standards. RS232: The electronic voltage and timing interface definition for the connection of electronic equipment RTCM: Radio Technical Commission for Maritime Services, (703) 684-4481, fax (703) 836-4229, 1800 Diagonal Road, Suite 600, Alexandria VA 22314 RTK OTF :Real-Time Kinematic (RTK) On-The-Fly (OTF) positioning. A DGPS technique for high precision positioning of moving objects. SMG: Speed Made Good. Marine term Giving speed to waypoint taking into effect the course you are steering. SOG: Speed Over Ground. Marine term to tell you to ignore tidal and current effects. SPS: Standard Positioning Service (civilian GPS). SA: Selective Availability (intentional degradation of SPS). , The USA military can turn off the accuracy of the system. see P code and C code. SNAFU: Situation Normal, All Fouled UP. Military term SOIT: FAA's Satellite Operational Implementation Team. Statute Mile: A unit of length equal to 5,280 feet or 1,760 yards (1,609 meters) used in the U.S. and some other English-speaking countries. Track: Your current direction of travel relative to a ground position (same as COG, Course Over Ground). Tropic of Cancer: An imaginary circle on the surface of the earth at 23.5°N latitude. The tropics are the two lines where the sun is directly overhead at noon on the two solstices - near June and December 21. The sun is directly overhead at noon on the Tropic of Cancer on June 21 (the beginning of summer in the Northern Hemisphere and the beginning of winter in the Southern Hemisphere) and the sun is directly overhead at noon on the Tropic of Capricorn on December 21 (the beginning of winter in the Northern Hemisphere and the beginning of summer in the Southern Hemisphere). Tropic of Capricorn: An imaginary circle on the surface of the earth at 23.5°S latitude. The tropics are the two lines where the sun is directly overhead at noon on the two solstices - near June and December 21. The sun is directly overhead at noon on the Tropic of Cancer on June 21 (the beginning of summer in the Northern Hemisphere and the beginning of winter in the Southern Hemisphere) and the sun is directly overhead at noon on the Tropic of Capricorn on December 21 (the beginning of winter in the Northern Hemisphere and the beginning of summer in the Southern Hemisphere). True North: The direction to the geographic North Pole. It is different from Magnetic North, by the value of the Mag. Var. USGS: U.S. Geological Survey. UPS: Universal Polar Stereographic, a version of UTM USNG:U.S. National Grid. UTM: Universal Transverse Mercator, A type of map projection. The grid lines you see on a USGS Quads represent a map projection known as Universal Transverse Mercator (UTM), and are 1000 meters apart. See map projections UTC: Coordinated Universal Time. There are 7 Universal Times (all within 1 second of each other), and UTC is the "coordinated version of 'Universal Time'", hence the word order of Coordinated Universal Time. The abbreviation UTC is a language-independent international abbreviation, it is neither English nor French. It means both 'Coordinated Universal Time' and 'Temps Universel Coordonné'. This is a time scale based on atomic clocks, by definition cesium clocks.
refer to the following websites; http://www.bipm.fr/enus/5_Scientific/c_time/time_server.html (BIPM Time Section; the world's GOVERNING BODY for civil atomic time-scales.), http://www.bipm.fr/enus/5_Scientific/c_time/time_1.html (BIPM Time Section), (for the French version of these two web pages, click on 'Version française'.) http://www.iers.org/iers/earth/rotation/utc/utc.html (The International Earth Rotation Service), http://www.rog.nmm.ac.uk/leaflets/time/time.html (The Royal Observatory Greenwich), http://ecco.bsee.swin.edu.au/chronos/GMT-explained.html (a good history of UTC and GMT), http://www.its.bldrdoc.gov/fs-1037/dir-009/_1277.htm (US. National Institute of Standards & Technology), http://www.npl.co.uk/npl/ctm/time_scales.html (UK's National Physical Laboratory), http://tycho.usno.navy.mil/systime.html & http://aa.usno.navy.mil/faq/docs/UT.html (US Naval Observatory), http://www.itu.int/radioclub/rr/arts02.htm (The International Telecommunications Union). VMG: Velocity Made Good. Marine term Giving velocity to waypoint taking into effect the course you are steering. VOG: Velocity Over Ground. Same as Ground Speed. WAAS: Wide Area Augmentation System. One government agency's attempt to correct the errors introduced into the signal by another government agency (The Military) Waypoint: A navigation fix. Usually a destination or point of reference. Also the name of this website. WGS84: World Geodetic Survey 1984. A common map datum reference. It is also the one we use on this site. WRC: World Radio Conference, an international conference where standards and interference issues are discussed. Y Code: P Code that has been encrypted.
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