Description of the ascii geo-VLBI data format AGVF

Introduction

Since AGVF format is ascii, its parsing incurs certain overheads. It is not recommended for adoption as am internal format for data analysis software packages. The main use case of AGVF format is a distribution of Level-2 data and results of data analysis of a specific VLBI experiment for geodesy and absolute astrometry between various data analysis software packages. Software analysis packages are supposed to be able to transform from the AGVF format to their internal format and vice versus without loss of information.

Level 2 VLBI data in the context of this document means results of fringe fitting program in a form of total group delay, total phase delay rate, and the total phase. The datafile in AGVF format contains also other variables that describes the VLBI experiment and results of its analysis. In the context of this document as set of data that corresponds that was schduled indepndently is called experiment. Experiment duration varies from 30 minutes to 15 days, althoug durations less than 1 hour and longer than 24 hours are unusual. During an experiment N stations observe M sources. Duration of time when an array or its part observe a given source before slewing to another source is called scan. Data collectated by a pair or stations during scan is called observation.

Structure of an AGVF file

A valid AVGF file consists of the format label and one or more chunks. Each chunk consists of 5 mandatory sections in the following order:

• FILE section
• PREA (preamble) section
• TOCS (table of contents) section
• DATA section
• HEAP heap section. Always empty. Reserved for future use.

Sections FILE, PREA, and TOCS describe the data, Section DATA presents the data. The data are considered as a set of four-dimensional arrays of one of the types: CHARACTER*1, INTEGER*2,INTEGER*4, INTEGER*8, REAL*4, REAL*8 and of one of the classes: SES, SCA, STA, BAS. Fortran notation is used for describing arrays: a) dimensions starts from 1; b) the index over first dimension runs first, i.e. elements order is a(i,j), a(i+1,j), a(i+2,j) etc. The dimensions 3 and 4 depend on the class of the data.

Throughout this document the strings that should be present in the AGVF file are highlighted. Examples that are not a part of definitions are also highlighted.

For historical reasons an individual array of data is called LCODE. An LCODE defines a 8-character long name, a string or arbitrary length with its description, class, type, and four dimensions. A class determines the scope of the LCODE and dimensions of the high level. Supported classes:

• SES The scope of the LCODE is the entire experiment, f.e. instance the experiment name. The dimensions 3 and 4 are 1, 1.
• SCA The scope of the LCODE is a given scan. The third dimension is the number of scans, the fourth dimension is 1.
• STA The scope of the LCODE is a given station, for instance apriori clock delay used for correlation. The third dimension is the number of observations at a given station, the fourth dimension is the station index.
• BAS The scope of the LCODE is a given observation, f.e. group delay. The third dimension is the total number of observations, the fourth dimension is 1.

An LCODE can be defined only once. There are five mandatory LCODEs that should be defined at the beginning of the first chunk. The AGVF format does not regulate which other LCODEs should be present, in which order, and in which chunk. The order of codes and their allocation in the chunk is selected by the generating software.

AGVF label

Example:

AGV format of 2005.01.14                                        

File section

Example:

FILE.1 /vlbi/gvf/db/20170117_pr1775_fr1_v001.bgv

Preamble section

• @section_length: defines the number of records in the preamble section except this one. This record should be the first record of the section. The first word of the Value is the number of records, the second is unit: keyword.
• GENERATOR: defines name and version of the program that generated this section. Version number should be defined that way that alphabetic sorting the value alphabetically should correspond to sorting the value chronologically.
• CREATED_AT: defines the creation date in format YYYY.MM.DD-hh:mm:ss

Example:

PREA.1 @section_length:     15 keywords

A preamble section of chunks others than the first has only one mandatory keyword: @section_length. An empty preamble section must have value 0 of this keyword.

Text section

The first record of the text section defines the number of chapters. This is a mandatory record. Format: Prefix Keyword Value Unit.

• Prefix — TEXT and the chunk index separated by dot.
• Keyword — @section_length:
• Value — the number of chapters in the section as an integer number.
• Unit — chapters.

Example:

TEXT.1 @section_length:      1 chapters

• Prefix — TEXT and the chunk index separated by dot.
• Keyword1 — @@chapter
• Value1 — the chapter index as an integer number. The first chapter has index 1.
• Value2 — the number of records in this chapter as an integer number. the number of records is zero for an empty chapter
• Unit1 — records
• Keyword1 — max_len:
• Value2 — the maximum number of characters in any record of this chapter.
• Unit1 — characters.

Example:

@@chapter 1      1  records, max_len:      16

Table of contents section

• Prefix — TOCS and the chunk index separated by dot.
• Keyword — @section_length:
• Value — the number of chapters in the section as an integer number.
• Unit — lcodes.

Example:

TOCS.1 @section_length:     53 lcodes

• Prefix — TOCS and the chunk index separated by dot.
• Keyword — LCODE -- a 8-characters long string with LCODE name. LCODE name should not contain blanks inside.
• Class — class of the LCODE. One of
  • SES — session class with the scope of entire experiment;
  • SCA — scan class with the scope of a given scan;
  • STA — station class with the scope of a given station;
  • BAS — baseline class with the scope of a given observation.

• Type — type of the data. One of
  • C1 — Character*1 data. Each element is one byte;
  • I2 — Integer*2, or 16-bit singed number;
  • I4 — Integer*4, or 32-bit singed number;
  • I8 — Integer*8, or 64-bit singed number;
  • R4 — Real*4, or 32-bit real number;
  • R8 — Real*8, or double precision, or 64-bit real number.

• Dim1 — the first dimension of the data. 1 for scalar data.
• Dim2 — the second dimension of the data. 1 for scalar or one-dimensional data.
• Description — a brief text that describes the LCODE.

Example:

TOCS.1 SITNAMES   SES  C1   8  10  IVS site names

There are 5 mandatory keywords that must be defined at the beginning of the first chunk. They all have session class and integer*4 type.

1. NUMB_OBS — the total number of observations;
2. NUMB_STA — the total number of stations;
3. NUMB_SCA — the total number of scans;
4. NOBS_STA — a one-dimension array sized as NUMB_STA. Contains the number of observations per stations;
5. OBS_TAB — a two dimensional array sized as (3,NUMB_OBS). The first row of the array is the number of scans, the second row is the index of the first station at a baseline for this observation; and the third row is the index of the second station at a baseline for this observation.

Data section

• Prefix — DATA and the chunk index separated by dot.
• Keyword — @section_length:
• Value — the number of chapters in the section as an integer number.
• Unit — records.

Example:

DATA.5 @section_length:     650859 records

• Prefix — DATA and the chunk index separated by dot.
• Lcode — LCODE name.
• Dim3 — the third dimension of the LCODE. The third dimension can be 0 or 1 for data of SES class.
• Dim4 — the fourth dimension of the LCODE. The fourth dimension can be 0 or 1 for data of STA or SES class.
• Dim1 — the first dimension of the LCODE.
• Dim2 — the second dimension of the LCODE.
• Value — the value of the array element. Recommended format for float numbers: 1PE15.7 for Real*4 data and for 1PD22.15 Real*8 data.

Example:

DATA.1 GR_DELAY 4466 0  1  1 7.267257847095946D-03
DATA.1 GR_DELAY 4466 0  2  1 7.267232471203255D-03

HEAP section

CHUN record

• Prefix — CHUN and the chunk index separated by dot.
• Keyword — @chunk_length:
• Value — the number records in the chunk, excluding this record and counting the AGVF format label if this is the first chunk.
• Unit — records.

Example:

CHUN.4 @chunk_size: 72856 records

Comments on using the AGVF format

Splitting an AGVF file into chunks is for facilitating an interface with other formats for Level-2 geodetic VLBI results. A valid AVGF file is supposed to have at least one chunk. Splitting data in chunks is determined by the generator process.

Some data are station dependent, for instance cable calibration, some are observation-dependent, for instance group delays. They are stored differently. Array OBS_TAB stored at the LCODE with the same name determines relationship between observation index and the indices of station-dependent parameters. For an observation with index k station-dependent LCODEs will have indices OBS_TAB(2,k) for the 1st (i.e. reference) station of a baseline and OBS_TAB(3,k) for the 2nd (i.e. remote) station of a baseline.

History of LCODE naming is traced in 70s. Renaming LCODEs is discouraged because of a risk of breaking compatibility. Addition of new LCODEs carries a low risk.

Appendix

Common LCODES

TOCS.1 NUMB_OBS   SES  I4   1   1  Number of observations in the session
TOCS.1 NUMB_SCA   SES  I4   1   1  Number of scans in the session
TOCS.1 NUMB_STA   SES  I4   1   1  Number of sites
TOCS.1 NOBS_STA   SES  I4  10   1  Number of observations per site
TOCS.1 OBS_TAB    SES  I4   3 4538  Observation tables: scan index, indices of the first and the second station
TOCS.1 SITNAMES   SES  C1   8  10  IVS site names
TOCS.1 BAND_NAM   SES  C1   2   1  Band names
TOCS.1 CORPLACE   SES  C1  32   1  Correlator place name
TOCS.1 COR_TYPE   SES  C1   8   1  Correlator type: MK3 MK4 K4 S2 VLBA MITAKA-1
TOCS.1 COR_VERS   SES  C1   8   1  Correlator software and/or hardware version
TOCS.1 DEL_RATE   BAS  R8   2   1  Phase delay rates per band (d/l)
TOCS.1 EXP_CODE   SES  C1  32   1  Experiment code
TOCS.1 EXP_DESC   SES  C1  80   1  Experiment description
TOCS.1 EXP_NAME   SES  C1  80   1  Experiment program name
TOCS.1 GDAMBSP    BAS  R8   2   1  Group delay ambiguity spacings per band (sec)
TOCS.1 GRDELERR   BAS  R8   2   1  Group delay errors per band (sec)
TOCS.1 GRRATERR   BAS  R8   2   1  Group delay rate errors per band (d/l)
TOCS.1 GR_DELAY   BAS  R8   2   1  Group delays per band (sec)
TOCS.1 GR_RATE    BAS  R8   2   1  Group delays rate per band (d/l)
TOCS.1 ION_GDEL   BAS  R8   1   1  Ionospheric contribution to group delay at the first band (sec)
TOCS.1 ION_GERR   BAS  R8   1   1  Uncertainty of ionospheric contribution to group delay at the first band (sec)
TOCS.1 ION_PRAT   BAS  R8   1   1  Ionospheric contribution to phase delay rate at the first band (sec)
TOCS.1 ION_RERR   BAS  R8   1   1  Uncertainty of ionospheric contribution to phase delay rate at the 1st band (d/l
TOCS.1 MJD_OBS    SCA  I4   1   1  MJD of fringe reference time at pseudo-UTC timecale for the scan (days)
TOCS.1 NUMB_SOU   SES  I4   1   1  Number of observed sources
TOCS.1 NUM_BAND   SES  I4   1   1  Number of frequency bands observed in the experiment
TOCS.1 NUM_CHAN   SES  I4   1   1  Number of frequency channels at all bands
TOCS.1 NUM_CHBN   SES  I4   1   2  Number of frequency channels per band
TOCS.1 N_AVBAND   SES  I4   1   1  Number of frequency bands for which information is availble
TOCS.1 PHDELERR   BAS  R8   2   1  Phase delay error (rad)
TOCS.1 PHRATERR   BAS  R8   2   1  Phase delay rate delay errors per band (d/l)
TOCS.1 PI_NAME    SES  C1  80   1  Name of the principal investigator
TOCS.1 QUALCODE   BAS  C1   2   2  Quality code as char*2 value: 5-9 is good, 0 -- non-detection, letter -- failure
TOCS.1 REC_MODE   SES  C1  80   1  Recording mode
TOCS.1 REF_FREQ   BAS  R8   2   1  Reference frequency for phase delay per band (Hz)
TOCS.1 SBDELERR   BAS  R8   2   1  Single-band delay errors per band (sec)
TOCS.1 SB_DELAY   BAS  R8   2   1  Single-band delays per band (sec)
TOCS.1 SCANNAME   SCA  C1  16   1  Scan name
TOCS.1 SCANPIMA   SCA  C1  10   1  Pima internal scan name
TOCS.1 SIT_COOR   SES  R8   3  10  Site coordinates in a crust-fixed terrestrial reference system: X, Y, Z (meters)
TOCS.1 SKYFRQCH   SES  R8  16   1  Sky frequency of channels in Hz
TOCS.1 SNRATIO    BAS  R8   2   1  Fringe amplitude signal to noise ratio (d/l)
TOCS.1 SOU_COOR   SES  R8   2  68  Source coordinates in a baricenteric reference system: right asc. decl. (rad)
TOCS.1 SOU_IND    SCA  I4   1   1  Source name index
TOCS.1 SRCNAMES   SES  C1   8  68  Source names
TOCS.1 STA_IND    BAS  I4   2   1  Station names indexes
TOCS.1 TOTPHASE   BAS  R8   2   1  Total fringe phases at time of arrival singal at station 1 per band (rad)
TOCS.1 UTC_MTAI   SES  R8   1   1  Difference UTC minus TAI at first time tag of the database (sec)
TOCS.1 UTC_OBS    SCA  R8   1   1  Pseudo-UTC time tag of fringe reference time for the scan (sec)
TOCS.2 ANT_GAIN   STA  R4   2   1  Antenna gain per band K/Jy
TOCS.2 APRCLOOF   STA  R8   1   1  Apriori clock offset used for correlation
TOCS.2 APRCLORT   STA  R8   1   1  Apriori clock rate used for correlation
TOCS.2 APR_DEL    BAS  R8   2   1  Apriori delay (sec)
TOCS.2 APR_PHAS   BAS  R8   2   1  Apriori fringe phase (rad)
TOCS.2 APR_PHGC   BAS  R8   2   2  Apriori fringe phase per station at the geocenter (rad)
TOCS.2 APR_RATE   BAS  R8   2   1  Apriori delay rate (d/l)
TOCS.2 BITSAMPL   SES  I2   1   1  Number of bits per sample
TOCS.2 CHAN_SDB   SES  I2  16   1  Index of lower (-1) or upper (1) sideband per channel
TOCS.2 CHAN_WDT   SES  R8  16   1  Frequency channel width in Hz per channel
TOCS.2 DELW_CEN   BAS  R8   2   1  Delay window center used for fringe search (sec)
TOCS.2 DELW_WDT   BAS  R8   2   1  Delay window width used for fringe search (sec)
TOCS.2 FRN_AMPL   BAS  R8   2   1  Normalzied fringe amplitude in range [0, 1]
TOCS.2 FRT_OFFS   SCA  R8   2   1  Fringe refrenence time offset relative to the scan start (sec)
TOCS.2 GCRESPHS   BAS  R8   2   1  Residual fringe phase at time of arrival singal at geocenter (rad)
TOCS.2 GC_PHASE   BAS  R8   2   1  Fringe phase at time of arrival singal at the conventionalgeocenter (rad)
TOCS.2 IND_CHN1   BAS  I2  10   1  Indexes of channels used in bandwidth synthesis in band 1
TOCS.2 IND_CHN2   BAS  I2   6   1  Indexes of channels used in bandwidth synthesis in band 2
TOCS.2 NOISERMS   BAS  R4   2   1  RMS of the fringe amplitude noise (d/l)
TOCS.2 NUM_AP1    BAS  I2  10   2  Number of accumulation periods used in band 1 per channel per sideband
TOCS.2 NUM_AP2    BAS  I2   6   2  Number of accumulation periods used in band 2 per channel per sideband
TOCS.2 NUM_SAM1   BAS  R8  10   1  Number of samples used in bandwidth synth. in band 1 per freq. chan and sideband
TOCS.2 NUM_SAM2   BAS  R8   6   2  Number of samples used in bandwidth synth. in band 2 per freq. chan and sideband
TOCS.2 NUSEDCHN   BAS  I2   2   1  Number of channels used in bandwidth synthesis per band
TOCS.2 PCAL_CM1   STA  R4   2  10  Complex phase cal (real/image) per channel at the 1st band
TOCS.2 PCAL_CM2   STA  R4   2   6  Complex phase cal (real/image) per channel at the 2nd band
TOCS.2 PCAL_FR1   STA  R8   1  10  Phase cal frequency per channel at the 1st band
TOCS.2 PCAL_FR2   STA  R8   1   6  Phase cal frequency per channel at the 2nd band
TOCS.2 POLARIZ    BAS  C1   2   2  Polarization label: RR, RL, LR, or LL
TOCS.2 RATE_CEN   BAS  R8   2   1  Rate window center used for fringe search (d/l)
TOCS.2 RATE_WDT   BAS  R8   2   1  Rate window width used for fringe search (d/l)
TOCS.2 RESGRRAT   BAS  R8   2   1  Residual group delay rate (d/l)
TOCS.2 RESMBDEL   BAS  R8   2   1  Residual multiband group delay (sec)
TOCS.2 RESPHAS    BAS  R8   2   1  Residual fringe phase
TOCS.2 RESPHRAT   BAS  R8   2   1  Residual phase delay rate (d/l)
TOCS.2 RESSBDEL   BAS  R8   2   1  Residual singleband group delay (sec)
TOCS.2 RES_GRDL   BAS  R8   2   1  Residual group delay reported by the post-correlator software (sec)
TOCS.2 RES_PHGC   BAS  R8   2   1  Resodual fringe phase per station at the geocenter (rad)
TOCS.2 RES_RATE   BAS  R8   2   1  Apriori phase delay rate reported by the post-correlator software (d/l)
TOCS.2 SAMPLRAT   SES  R8   1   1  Sample rate in Hz
TOCS.2 SCAN_DUR   BAS  R8   2   1  Scan duration per band (sec)
TOCS.2 SPCH_WDT   SES  R8  16   1  Spectral channel width in Hz per channel
TOCS.2 TSYS1      STA  R4   1  10  System temperature per channel at the 1st band (K)
TOCS.2 TSYS2      STA  R4   1   6  System temperature per channel at the 2nd band (K)
TOCS.2 UVSTAORD   BAS  I2   1   1  Original station order in the baseline: 1 (ascending) or -1 (descending)
TOCS.2 UV_CHN1    BAS  R4   2  10  UV data: real and image part per channel at the 1st band (d/l)
TOCS.2 UV_CHN2    BAS  R4   2   6  UV data: real and image part per channel at the 2nd band (d/l)
TOCS.3 AIR_TEMP   STA  R8   1   1  Air temperature at the station (K)
TOCS.3 ATM_PRES   STA  R8   1   1  Atmospheric pressure at the station (Pa)
TOCS.3 CABL_DEL   STA  R8   1   1  Cable delay (sec)
TOCS.3 CABL_SGN   SES  I2  10   1  Cable sign: +1 or -1
TOCS.3 CAL_INFO   SES  I4   4   1  Information about class and type of available calibrations
TOCS.3 CAL_NAME   SES  C1   8   1  Name of available calibrations
TOCS.3 MEANCABL   SES  R8  10   1  Mean cable delay (sec)
TOCS.3 N_CALIB    SES  I2   1   1  Number of available calibrations
TOCS.3 REL_HUMD   STA  R8   1   1  Relative humidity at the station (0-1)

TOCS.1 EXPSERNO   SES  I2   1   1  Experiment serial number at correlator
TOCS.1 MK3_DBNM   SES  C1  10   1  Mark-3 DBH database name
TOCS.1 PIMA_CNT   SES  C1 128   1  Full path name of pima control file
TOCS.1 PIMA_VER   SES  C1  24   1  Version of PIMA software
TOCS.2 PIND_OBS   BAS  I4   1   1  Internal index of observation used by PIMA
TOCS.2 SRT_OFFS   SCA  R8   1   1  Scan refrenence time offset relative to the scan start (sec)
TOCS.4 ATM_CNS    SES  R8  10  32  Reciprocal weights of constraints on atm. path delay rate per station, soltype
TOCS.4 ATM_INTR   SES  R8  32   1  Lenght of time span between spline nodes for atm. path delay per soltyp (sec)
TOCS.4 AUTO_SUP   BAS  I4   1   1  Bit field of automatic suppression status for combination of observables
TOCS.4 BAND_2ND   BAS  I2   1   1  Bit field with status of information about the second band observations
TOCS.4 BAS_USE    SES  I4  45   1  Bit field of baseline selection status
TOCS.4 BSCL_CNS   SES  R8  45  32  Reciprocal weights of constraints on basdep. clock, per baseline, per soltype
TOCS.4 BSCL_EST   SES  I4  45   1  Estimation status for baseline depedent clock, per baseline
TOCS.4 CAL_STS    SES  I4  10   1  Bit field of using available calibrations per station, per calibration
TOCS.4 CLO_CNS    SES  R8  10  32  Reciprocal weights of constraints on clock rate per station, per solution type
TOCS.4 CLO_INTR   SES  R8  32   1  Lenght of time span between spline nodes for clock function per soltyp (sec)
TOCS.4 DATYP      SES  I2   1   1  Type of the observable or a combination of observables used in the solution
TOCS.4 DGCL_EST   SES  I2  10  32  Degree of global clock function polynomial per station, per solution type
TOCS.4 EDIT_STS   SES  I4   1   1  Bit field of database editing status for different types of solutions
TOCS.4 EFF_FREQ   BAS  R8   3   2  Effective ionospheric frequencies for gr.del, ph.del, ph.rate per band (Hz)
TOCS.4 EOP_CNS    SES  R8  11  32  Reciprocal weights of constraints on EOP related parameters
TOCS.4 EOP_EST    SES  I4  11   1  Estimation status for EOP-related parameters
TOCS.4 NUM_CLBR   SES  I4   1   1  Number of clock breaks in the experiment
TOCS.4 NUM_CLRF   SES  I4   1   1  Number of clock reference stations
TOCS.4 N_GRAMB    BAS  I4   2   1  Number of group delay ambiguities to be added to measured group delays per band
TOCS.4 N_PHAMB    BAS  I4   2   1  Number of phase delay ambiguities to be added to measured phase delays per band
TOCS.4 RWBASNAM   SES  C1  16  45  Baseline names for additive baseline-dependent reweighting parameters
TOCS.4 RWDELVAL   SES  R8  32  45  Additive baseline-dependent reweighting parameters for delays (sec)
TOCS.4 RWRATVAL   SES  R8  32  45  Additive baseline-dependent reweighting parameters for delay rates (d/l)
TOCS.4 SOCO_CNS   SES  R8  68  32  Reciprocal weights of constraints on source coordinates per object, per soltype
TOCS.4 SOCO_EST   SES  I4   2  68  Estimation status for source coordinats per component, per object
TOCS.4 SOU_USE    SES  I4  68   1  Bit field of source selection status
TOCS.4 STA_CLRF   SES  C1   8   1  Names of clock reference stations
TOCS.4 STA_USE    SES  I4  10   1  Bit field of station selection status
TOCS.4 STPS_CNS   SES  R8  10  32  Reciprocal weights of constraints on site positions per site, per solution type
TOCS.4 STPS_EST   SES  I4   3  10  Estimation status for station positions per component, per station
TOCS.4 SUPMET     SES  I2   1   1  Code of the suppression method used in the solution
TOCS.4 TEC_STS    SES  I4  10   1  Flag of availability/usage of the external ionosphere calibration
TOCS.4 TIL_INTR   SES  R8  32   1  Lenght of time span between spline nodes for atmospphere tilt per soltyp (sec)
TOCS.4 TLOF_CNS   SES  R8  10  32  Reciprocal weights of constraints on atm. tilt offset per station, per soltype
TOCS.4 TLRT_CNS   SES  R8  10  32  Reciprocal weights of constraints on atm. tilt rate per station, per soltype
TOCS.4 USER_REC   BAS  I4   1   1  Bit field of analyst defined recovery status for combination of observables
TOCS.4 USER_SUP   BAS  I4   1   1  Bit field of analyst defined suppression status for combination of observables
TOCS.5 APR_EOP    BAS  R8   3   2  Aprori EOP array as Euler angles and its derivatives (rad)
TOCS.5 AZIMUTH    STA  R8   1   1  Apparent source azimuth at both stations of the baseline (rad)
TOCS.5 DER_DEL    BAS  R8  64   1  Array of partial derivatives of theoretical path delay wrt parameters of the mod
TOCS.5 DER_RAT    BAS  R8  64   1  Array of partial derivatives of theoretical delay rate wrt parameters of the mod
TOCS.5 ELEV       STA  R8   1   1  Apparent source elevation at both stations of the baseline (rad)
TOCS.5 EOP_TAB    SES  R8  15   3  Table of aprori EOP as Euler angles with frequencies > 2 cpd filtered out
TOCS.5 MJD_EOP    SES  I4   1   1  Modified Julian date of the first epoch for the table of apriori EOP
TOCS.5 NUT_DER    BAS  R8   2   1  Partial derivatives wth nutation deaily offset parameters (sec)
TOCS.5 N_APREOP   SES  I4   1   1  Number of nodes with apriori EOP
TOCS.5 STEP_EOP   SES  I4   1   1  Step of the EOP table of apriori EOP (sec)
TOCS.5 TAI_EOP    SES  I4   1   1  TAI time tag of first epoch of the table of apriori EOP (sec)
TOCS.5 THGR_DEL   BAS  R8   1   1  Theoretical group delay (sec)
TOCS.5 THPH_DEL   BAS  R8   1   1  Theoretical phase delay (sec)
TOCS.5 THPH_RAT   BAS  R8   1   1  Theoretical phase delay date (d/l)
TOCS.5 TH_PROG    SES  C1  64   1  Name and version of the program which computed theoretical path delays
TOCS.5 TH_RUDAT   SES  C1  24   1  Date and time of theoretical delay compuation
TOCS.5 UV_COOR    BAS  R8   2   1  UV coordinates of the baseline vector projectioncalibration