Spectrum TM-4 time and frequency system data

The TM-4 is used as an event logger to log shot times from digishot. The 'tagger' data set includes all output from the TM-4. The 'shot' data set includes only the event messages (message #62)

Spectra provides primary shot timing aboard Langseth. The TM-4 is used for qc and backup purposes.

Message descriptions
Message # Type Form Explanation
50 ACKNOWLEDGE CRLF  
51 DATE AND TIME MMDDYYYY,HHMMSSCRLF MMDDYYYY is UTC month, day, and year HHMMSS is UTC hours, minutes and seconds
52 POSITION WWWW.WW,X,YYYYY.YY,Z,A,NCRLF W = latitude in DDMM.MM

X = hemisphere N or S

Y = longitude in DDDMM.MM

Z = hemisphere E or W

A = GPS availability (0 = not available, 1 = available)

N = number of satellites used (0-9, A[10], B[11], C[12])

53 ALTITUDE SXXXXX,MCRLF S = sign (+ or -)

X = altitude (5 digits)

M = altitude units (meters)

55 MASK ANGLE AND MAP DATUM SETTING X,47CRLF X = 0 for 5 degrees

X = 1 for 15 degrees

X = 2 for 20 degrees

47 = two digit map datum code (fixed at WGS84)

56 USER TIME BIAS SXXXXXCRLF S = sign (+ or -)

X = bias value (5 digits)

57 TIMING MODE XCRLF X = 0 for Dynamic Timing Mode

X = 1 for Static Timing Mode

X = 3 for Auto Survey Mode

59 GEOMETRIC QUALITY AND ALMANAC STATUS X,YCRLF X = GQ (0-9)

Y = 0 (Almanac OK)

Y = 1 (no Almanac)

Y = 2 (Almanac is old)

60 TIME PORT DATA RATE AND MULTIPLEXER #1 STATUS X,YCRLF X = 0 (1200 baud) Y = 0 for 10 MHz output

X = 1 (2400 baud) Y = 1 for 5 MHz output

X = 2 (4800 baud) Y = 2 for 1 MHz output

X = 3 (9600 baud) Y = 3 for 100 kHz output

X = 4 (19200 baud) Y = 4 for 10 kHz output

X = 5 (38400 baud) Y = 5 for 1 kHz output

X = 6 (57600 baud) Y = 6 for IRIG output (if installed)

X = 7 (115200 baud) Y = 7 for PPS output

Y = 8 for OFF (newer TM-4's only)

61 TIMING STATUS W,CRLF W = 0 (time not valid)

W = 1 (Time Valid)

62 EVENT TIME-TAG MMDDYYYY,HHMMSS.SSSSSSSCRLF MMDDYYYY = UTC date of event

HHMMSS.SSSSSSS = UTC time of event

63 POP/ETT STATUS X,P,MMDDYYYY,HHMMSS.SSSSSSS,RRRRRRRRCRLF X = 0 for ETT/POP OFF

X = 1 for POP One-Shot

X = 2 for POP Repeat

X = 3 for ETT

P = + for positive polarity

P = - for negative polarity

P = 0 when POP/ETT Mode is OFF

MMDDYYYY is the POP date (UTC)

HHMMSS.SSSSSSS is the POP time (UTC)

RRRRRRRR is the POP repeat interval

64 OSCILLATOR TUNING MODE XCRLF X = 1 for Mode 1 (oscillator warm-up)

X = 2 for Mode 2 (course adjust)

X = 3 for Mode 3 (course adjust standby)

X = 4 for Mode 4 (fine adjust)

X = 5 for Mode 5 (fine adjust hold)

Note: See OSCILLATOR MODES on page 11 of the Spectrum manual for an explanation of these Oscillator Tuning Modes.
65 ALARM STATUS X,Y,ZCRLF X = 0 for No Coast condition

X = 1 for Coast Alarm condition See Message #79 for Coast Timer.

Y = 0 for Antenna Good

Y = 1 for Antenna Current Sense Fault condition

Z = 0 for 10 MHz Frequency Output Good

Z = 1 for 10 MHz Frequency Output Fault condition

See HARDWARE FAULT MONITORING on page 14 of Spectrum manual for an explanation of Antenna Alarm.

68 MULTIPLEXER #2 STATUS XCRLF X = 0 for 10 MHz output

X = 1 for Mux1 mirror

X = 2 for PPS

X = 3 for output option 1

X = 4 for output option 2

X = 5 for output option 3

X = 6 for baseband IRIG (if installed)

X = 7 for baseband NASA-36 (if installed)

X = 8 for OFF (newer TM-4's only)

69 TRACKING CHANNEL STATUS VV,W,X,Y,....VV,W,X,Y,ZCRLF VV = PRN of satellite being tracked

W = constellation status:

0 = not included in current constellation

1 = included in current constellation

X = tracking status:

A = acquisition/reacquisition

S = searching

0-9 = SQ

Y = Ephemeris status:

0 = not collected

1 = collected

Z = receiver status:

2 = search the sky

3 = Almanac collect

4 = Ephemeris collect

5 = acquisition

6 = position

NOTE: VV,W,X,Y repeats twelve times, corresponding to each of the twelve channels.

70 SERIAL TIME MESSAGE FORMAT XCRLF X = 0 for standard output

X = 1 for NTP output (optional)

X = 2 for NMEA output

71 SERIAL TIME CODE FORMAT XCRLF X = 0 for IRIG B output

X = 1 for NASA-36 output

72 ETT PARAMETERS X,PCRLF X = 0 (ETT off)

X = 1 (ETT on)

74 POP PARAMETERS (Simultaneous ETT/POP units) X,P,MMDDYYYY,HHMMSS.SSSSSSS,RRRRRRRR,WCRLF X = 0 for POP Off

X = 1 for POP One-Shot

X = 2 for POP Repeat

P = + for positive polarity

P = - for negative polarity

MMDDYYYY is the POP date (UTC)

HHMMSS.SSSSSSS is the POP time (UTC)

RRRRRRRR is the POP repeat interval in milliseconds

W = 0 for 1 μs pulse width

W = 1 for 10 μs pulse width

W = 2 for 100 μs pulse width

W = 3 for 1 ms pulse width

W = 4 for 10 ms pulse width

W = 5 for 50 ms pulse width

W = 6 for 100 ms pulse width

W = 7 for 250 ms pulse width

W = 8 for Level Hold

75 SPEED OVER LAND and HEADING SSS.SS,HHH.HCRLF SSS.SS indicates speed over land in meters/sec

HHH.H indicates course in degrees decimal

76 ADDITIONAL NMEA INFORMATION DDMM.MMMM,N,DDDMM.MMMM,W,SAAAAA.A,M,G,UU,PP.P,ZZZ.ZZ,YYY.YCRLF DDMM.MMMM is latitude in degrees and decimal minutes

N is north or south (N, S)

DDDMM.MMMM is longitude in degrees and decimal minutes

W is west or east (W, E)

S is sign of altitude above or below sea level (+,-)

AAAAA.A is altitude (in meters) (0-18000)

M is altitude units (meters)

G is GPS status (0= fix not valid, 1= fix valid)

UU is number of satellites used in navigation solution (0-12)

PP.P is estimated horizontal dilution of precision (0-99.9)

ZZZ.ZZ is speed over ground in knots

YYY.Y is course over ground in degrees

77 PHASE LOCK STATUS X,CRLF
78 ADDITIONAL USER OPTION SETTINGS A,B,C,D,E,FCRLF A = 0 for Antenna Alarm Disabled

A = 1 for Antenna Alarm Enabled (default)

B = 0 for PPS Source 0 (See Message #24 for definitions)

B = 1 for PPS Source 1

B = 2 for PPS Source 2

B = 3 for PPS Source 3

Fields C-F are reserved.

79 COAT TIMER HHHHMMSSCRLF HHHHMMSS = Amount of time (Hours, Minutes, Seconds) that the unit has been in Coast (Mode 3 or Mode 5)
80 PHASE LOCK STATUS X, CRLF
81 LEAP SECONDS?GPS TIME X,Y,±ZZCRLF X = 0 for TM-4 operation in GPS Time (reserved for future feature, currently disabled)

X = 1 for TM-4 operation in UTC Time (default)

Y = 0 for Leap Second data not valid

Y = 1 for Leap Second data valid

±ZZ = UTC/GPS Time Offset, in whole seconds

The difference between UTC Time and GPS Time is the number of Leap Seconds that have been introduced to UTC Time since the beginning of GPS Time. (GPS Time is never adjusted for Leap Seconds.) The ìUTC Offsetî from GPS Time is in the information data stream broadcast by the GPS satellites. The TM-4 stores the previously known value, but until the TM-4 makes contact wisatellites and downloads the current"UTC Offset", the data cannot be considered to be valid.