Inverse Mapping of Polarised Optical Emission from Pulsars : Basic
  Formulation and Determination of Emission Altitude
  We present an inverse mapping approach to determining the emission height of
the optical photons from pulsars, which is directly constrained by empirical
data. The model discussed is for the case of the Crab pulsar. Our method, using
the optical Stokes parameters, determines the most likely geometry for emission
including magnetic field inclination angle ($\alpha$), observers line of sight
angle ($\chi$) and emission height. We discuss the computational implementation
of the approach, along with any physical assumptions made. We find that the
most likely emission altitude is at 20% of the light cylinder radius above the
stellar surface, in the open field region. We also present a general treatment
of the expected polarisation from synchrotron source with a truncated power law
spectrum of particles.
