USGS CMG "Geodetic" Definition

• InfoBank geodetic survey Activity-ID naming convention:
  

  California

  |Pt. Reyes| San Francisco| San Mateo Co.| |Santa Cruz Co.| Monterey Bay| Carmel Bay| |Estero Bay| Santa Barbara Co.| Ventura Co.| |Hawaii| Maui| Oahu|

• "Geodetic" (as used within the CMG InfoBank ) is the horizontal and vertical positioning of a ship, platform, benchmark, survey location, etc.
• The positions are commonly UTM x/y/z or latitude, longitude, elevation triplets.

  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.

  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.
  

• Geodetic information occurs in the InfoBank as:

  scattered	< Activity-ID >.utm files containing UTM X,Y,Z information.
  metadata	information about geodetic inventory of gear, deployment of gear, operation of gear, and magnetic media.

• InfoBank geodetic data file names:

  <Activity-ID>.utm

  UTM X,Y,Z of geodimeter location, control points, and data points

• InfoBank geodetic metadata file names:

  <Activity-ID>.conditions	skies, temperature, barometric pressure, wind, precipitation, sea state, optical siting, etc. conditions
  <Activity-ID>.data_files	list and descriptions of raw, edited, imagery, etc. data files
  <Activity-ID>.geo_equipment	geodetic equipment systems metadata
  <Activity-ID>.header	description of location and dates
  <Activity-ID>.image_files	list and descriptions of image files
  <Activity-ID>.location	ellipsoid, horizontal datum, vertical datum, UTM zone, latitude, longitude, elevation, northing, easting metadata
  <Activity-ID>.notes	notes and comments
  <Activity-ID>.observations	special observations
  <Activity-ID>.post-processing	post-data collection processing metadata
  <Activity-ID>.precision	horizontal and vertical precision and accuracy metadata
  <Activity-ID>.procedure	field procedures
  <Activity-ID>.synopsis	synopsis of activity

"Every path serves a purpose." -- Gene Oliver