Hints for converting from Tempo1 to Tempo2
Tempo2 is based on the original fortran tempo1 software and therefore should be relatively straight-forward for anyone confident with tempo1 to start using tempo2. Tempo2 can deal with simple tempo1 parameter and observations files:
tempo2 -f mypar.par mytim.tim -tempo1
By default tempo2 does not produce the standard tempo1 output files (e.g. resid2.dat, tempo.lis). The plugin features of tempo2 should supercede these tempo1 outputs. More complex tempo1 observations files (that include large numbers of jumps etc.) should be converted to tempo2 formats. Ingrid has produced a great script to undertake this conversion (Ingrid's hints).
It is possible to convert a tempo1-format parameter file into a tempo2 format file using
tempo2 -gr transform tempo1.par tempo2.par
which will produce a new file (tempo2.par) that has been correctly converted to be compliant with IAU 2000 resolutions.
Improved features of tempo2 compared to tempo1 (taken from the Hobbs, Edwards & Manchester 2006 paper)
For coordinate systems, propagation delays and ephemerides, tempo2
- is compliant with IAU 2000 resolutions and implements updated precession and nutation models, polar motion, the ICRS coordinate system and TCB (SI units) instead of TDB.
- corrects the observing frequency for relativistic time dilation
- uses an improved tabulation of the Solar system Einstein delay
- includes atmospheric propagation delays
- includes the Shapiro delay due to the planets; and
- includes the second order Shapiro delay due to the Sun
For the fitting routines, tempo2
- has the ability to simultaneously fit to the timing residuals of multiple pulsars
- implements frequency-dependent fitting (not only DM delays)
- has the ability to fit for DM at each epoch using simultaneous observations
- allows fits for an arbitrary number of pulse frequency derivatives, DM derivatives and glitches
- simplifies and provides flexible methods for placing arbitrary offsets between TOAs obtained at different frequencies or observatories
- can whiten data using harmonically related sinusoids
- provides a brute-force method for obtaining timing solutions
- fully inclues the effect of secular motion of the pulsar; and
- includes the orbital parallax terms in the binary models.
The predictive mode in tempo2 provides both time and frequency dependent predictions and therefore deals correctly with
- the Earth rotation; and
- binary motion
Other miscellaneous improvements include
- generalised input formats
- generalised output formats
- the ability to simulate pulsar-arrival times
- the implementation of numerous graphical interfaces
- calculating the post-fit residuals (instead of predicting them)
- the ability to update binary parameters to a given epoch
- generalised clock-correction routines.