High Precision Timing of PSR J0437–4715

Systematic effects currently dominate the timing residuals of the pulsar PSR J0437–4715. These systematics arise from transformations that occur during the propagation and detection of radio waves. The transformation properties of polarized radiation are related to the Lorentz group, and such effects may be represented using Lorentz transformations. These effects may be removed using the techniques of polarimetric self-calibration. Alternatively, an invariant profile may be formed from the polarimetric analogue of the Lorentz invariant I 2 – Q 2 – U 2 – V 2 and used for pulsar timing. Observations of PSR J0437–4715 are presented that show the consistency between these two techniques.