USNO GPS Data Categories Explanation



ColumnData CategoryExplanation
1PRNthe satellite vehicle PRN number
2MJDthe five digit Modified Julian Date and the fraction of day at the midpoint of the track
3BGTK
HHMM
hour and minute (in UTC) of the start of the track
tracks begin at 1 second after the minute
4TRK
SEC
the track length in seconds (a full track is 780 seconds)
5MC-GPS
NS
the time difference (measured in nanoseconds) between UTC(USNO MC) and GPS time, referred to the midpoint of the pass via a linear fit
6SLOPE
PS/S
the slope determined via the linear fit to produce MC-GPS (measured in picoseconds per second)
7RMS
NS
the root mean square of the residuals of the linear fit used to produce MC-GPS
8SAMP
N
the number of data points used in the fit to produce MC-GPS
9EL
DG
the elevation (in degrees) of the satellite at the midpoint of the track (data prior to MJD 50846 gives elevation at beginning of track)
10AZM
DEG
the azimuth (in degrees) of the satellite at the midpoint of the track (data prior to MJD 50846 gives azimuth at beginning of track)
11ION
NS
the modeled ionospheric delay (measured in nanoseconds) referred to the midpoint of the pass via a linear fit
12MC-SATCL
NS
the time difference (measured in nanoseconds) between UTC(USNO MC) and satellite time, referred to the midpoint of the pass via a linear fit
13SLOPE
PS/S
the slope determined via the linear fit to produce MC-SATCL (measured in picoseconds per second)
14TROP
NS
the modeled tropospheric delay (measured in nanoseconds) referred to the midpoint of the pass via a linear fit


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