1

PRN

the satellite vehicle PRN number

2

MJD

the five digit Modified Julian Date and the fraction of day at the midpoint of the track

3

BGTK
HHMM

hour and minute (in UTC) of the start of the track
tracks begin at 1 second after the minute

4

TRK
SEC

the track length in seconds (a full track is 780 seconds)

5

MC-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

6

SLOPE
PS/S

the slope determined via the linear fit to produce MC-GPS (measured in picoseconds per second)

7

RMS
NS

the root mean square of the residuals of the linear fit used to produce MC-GPS

8

SAMP
N

the number of data points used in the fit to produce MC-GPS

9

EL
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)

10

AZM
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)

11

ION
NS

the modeled ionospheric delay (measured in nanoseconds) referred to the midpoint of the pass via a linear fit

12

MC-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

13

SLOPE
PS/S

the slope determined via the linear fit to produce MC-SATCL (measured in picoseconds per second)

14

TROP
NS

the modeled tropospheric delay (measured in nanoseconds) referred to the midpoint of the pass via a linear fit