Instrument: Global Positioning System Receiver

Instrument Short Name: GPS
(http://vocab.nerc.ac.uk/collection/L05/current/POS03/)
Instrument Description:

The Global Positioning System (GPS) is a U.S. space-based radionavigation system that provides reliable positioning, navigation, and timing services to civilian users on a continuous worldwide basis. The U.S. Air Force develops, maintains, and operates the space and control segments of the NAVSTAR GPS transmitter system. Ships use a variety of receivers (e.g. Trimble and Ashtech) to interpret the GPS signal and determine accurate latitude and longitude.

PI supplied instrument name: Global Positioning System Receiver
Dataset-specific description

NorthStar 941 GPS receiver NMEA (National Marine Electronics Association) output

Format:
 $--RMC,hhmmss.ss,S,lat,a,lon,a,x.x,y.y,ddmmyy,m.m,d*hh<cr><lf>
  Time = UTC of position fix
  S = Status ("A" = valid, "V" =  receiver warning)
  Lat & Lon
  x.x = speed over ground (knots)
  y.y = Course over ground (degrees true)
  ddmmyy = date
  m.m,d = magnetic variation, degrees ("E" subtracts from true, "W" adds to true)