TOA LINES

TOAs are entered, one per line, in one of four formats, called
'Princeton', 'Parkes', 'Interchange TOA (ITOA)', or 'Tempo2' format.
TOAs in Princeton, Parkes and Tempo2 formats are assumed to be
referenced in an observatory time scale (see TIME SCALES, below).  TOAs
in ITOA format are assumed to be referenced to UTC.  TOAs are reported
as MJD, except that TOAs reported using the Princeton format may also be
MJD-39126 (also called '1966 day number').  Use of the latter is
discouraged.

One-character observatory codes correspond to lines in the observatory
coordinate file for '1' through '9' and 'a' through 'z'.  Code '0' indicates
the geocenter.  Code '@' indicates the solar system barycenter (for which
neither geometric nor clock corrections are applied).  The two-character
observatory codes used in the ITOA format are given in the observatory
coordinate file.  In Tempo2 format either the one-character or
two-character codes can be used.

Princeton Format

  columns     item
    1-1     Observatory (one-character code)
    2-2     must be blank
    16-24   Observing frequency (MHz)
    25-44   TOA (decimal point must be in column 30 or column 31)
    45-53   TOA uncertainty (microseconds)
    69-78   DM correction (pc cm^-3)

Parkes Format

  columns     item
    1-1     must be blank
    26-34   Observing frequency (MHz)
    35-55   TOA (decimal point must be in column 42)
    56-63   Phase offset (fraction of P0, added to TOA)
    64-71   TOA uncertainty (microseconds)
    80-80   Observatory (one-character code)

ITOA Format

  columns     item
    1-2     ignored, but must not be blank (often PSRNAME goes here)
   10-28    TOA (decimal point must be in column 15)
   29-34    TOA uncertainty (microseconds)
   35-45    Observing frequency (MHz)
   46-55    DM correction (pc cm^-3)
   58-59    Observatory (two-letter code)
 
Tempo2 Format

  This format uses whitespace-separated fields rather than fixed column
  locations for the contents.  To use this format, the first line of
  each TOA file must contain the command 'FORMAT 1'.

  field       item
    1       Name of profile data file (ignored but must not be blank)
    2       Observing frequency (MHz)
    3       TOA
    4       TOA uncertainty (microseconds)
    5       Observatory (one- or two-character code)
    6+      Optional flags (see below)

Tempo2 Flags

Following the five basic fields, Tempo2 format TOA lines can optionally
contain any number of flags in the format "-flag value".  Flags may
be used for JUMP or INFO statments (see Free-format header manual
section).  Additionally, the following flags are currently understood by
tempo:

  flag        description
    -to     The floating-point value in seconds is added to the TOA,
            as if a TIME command.

    -padd   The floating-point value in turns in added to the computed
            pulse phase, as if a PHASE command.