USGS CMG "Navigation" Definition

• "Navigation" (as used within the CMG InfoBank ) is the position of a platform at a specific time.
• The position is commonly a latitude, longitude pair.
• UTM x/y coordinates are sometimes used.

  Latitudes and longitudes

• Latitudes are parallel to the Equator and range from -90 degrees (South Pole) to+90 degrees (North Pole).
• The northern hemisphere has positive latitudes.
• The southern hemisphere has negative latitudes.
• Longitudes are perpendicular to the Equator are range from -180 degrees (International Date Line) to +179.99999... degrees (just west of the International Date Line).
• Under this convention -- the western hemisphere has negative longitudes and the eastern hemisphere has positive longitudes.

  UTMs

• UTM x/y coordinates are a rectangular coordinate system with units in meters from the equator (the "y" value) and meters from a central meridian (the "x" value).
• The central meridian defines a 6 degree wide zone.
• The zone must beknown for uniqueness.
• Zone 1 starts at the International Date Line, has a central meridian 3 degrees counterclockwise around the earth from there (-177d), and continues another 3degrees.
• Zone 2 has a central meridian of -171d (-177 - 6), and so on around the globe.

  Derivative information

• Course, speed, distance, and Eotvos are derived from pairs of positions and their associated times.

• Navigation information occurs in the InfoBank as:

  scattered	< Activity-ID >.0# or <Activity-ID>.6# files containing time sequential information.
  analog	physical records, usually electrostatic or photostatic rolls
  metadata	information about navigation analog paper rolls, inventory of gear, deployment of gear, operation of gear, magnetic tapes and floppies, paper printer listings, and platform movements.

• InfoBank navigation data file names:

  <Activity-ID>.00#	Transit satellite information
  <Activity-ID>.01#	Dead reckoning latitude/longitude
  <Activity-ID>.02#	Platform position updates
  <Activity-ID>.03#	Loran C information
  <Activity-ID>.04#	Omega information
  <Activity-ID>.05#	Satellite Integrated Navigation (SINS) latitude/longitude
  <Activity-ID>.06#	Global Positioning System (GPS) latitude/longitude
  <Activity-ID>.07#	Latitude, longitude, Eotvos, course, speed, distance
  <Activity-ID>.08#	Farnella ABC latitude/longitude
  <Activity-ID>.60#	Raw transponder ranges
  <Activity-ID>.61#	Transponder control positioning
  <Activity-ID>.62#	Raw Miniranger ranges
  <Activity-ID>.63#	Miniranger operations table
  <Activity-ID>.64#	Miniranger land table in latitude/longitude
  <Activity-ID>.65#	Latitude, longitude, UTM positions
  <Activity-ID>.66#	Radar information
  <Activity-ID>.67#	Raw Del Norte ranges
  <Activity-ID>.68#	Miniranger land table in UTMs
  <Activity-ID>.69#	Edited ranging navigation in latitude/longitude

• InfoBank navigation metadata file names:

  <Activity-ID>.bathgravmagnav	bathymetry + gravity + megnetics + navigation systems metadata
  <Activity-ID>.bathgravnav	bathymetry + gravity + navigation systems metadata
  <Activity-ID>.bathmagnav	bathymetry + magnetics + navigation systems metadata
  <Activity-ID>.bathnav	bathymetry + navigation systems metadata
  <Activity-ID>.bottomtransponder	bottom transponder systems metadata
  <Activity-ID>.courserecorder	course recorder systems metadata
  <Activity-ID>.deadreckoning	deadreckoning systems metadata
  <Activity-ID>.delnorte.rangerange	del norte range/range systems metadata
  <Activity-ID>.dopplersonar	doppler sonar systems metadata
  <Activity-ID>.gps	GPS systems metadata
  <Activity-ID>.integratednavigation	integrated navigation systems metadata
  <Activity-ID>.lines	lines systems metadata
  <Activity-ID>.lorac	lorac systems metadata
  <Activity-ID>.lorana	loran-a systems metadata
  <Activity-ID>.loranc	loran-c systems metadata
  <Activity-ID>.loranc.rhorho	loran-c rho/rho systems metadata
  <Activity-ID>.miniranger	miniranger systems metadata
  <Activity-ID>.navplot.bridge	bridge plots and charts metadata
  <Activity-ID>.navplot.computer	computer plots and charts metadata
  <Activity-ID>.navplot.lab	lab plots and charts metadata
  <Activity-ID>.pcode	pcode systems metadata
  <Activity-ID>.precisionrangingsystem	precision ranging systems metadata
  <Activity-ID>.radar	radar systems metadata
  <Activity-ID>.raydist	raydist systems metadata
  <Activity-ID>.sextant	sextant systems metadata
  <Activity-ID>.sonotracktransducer	sonotrack transducer systems metadata
  <Activity-ID>.stations	stations systems metadata
  <Activity-ID>.transitsatellite	transit satellite systems metadata
  <Activity-ID>.yonav	yonav navigation acquisition systems metadata

• A "time" key is associated with each record for correlation with other scattered information datasets.

"We will be known by the tracks we leave behind." -- Dakota proverb