PSRCHIVE and PSRFITS: Definition of the Stokes Parameters and Instrumental Basis Conventions

TL;DR

This paper clarifies the mathematical conventions for describing electromagnetic wave polarization used in pulsar astronomy, compares them with international standards, and provides calibration data for instrumental parameters.

Contribution

It establishes the PSR/IEEE convention for polarization in pulsar astronomy and offers practical parameters and calibration data for instrument characterization.

Findings

Defined the PSR/IEEE polarization convention

Compared with IAU/IEEE standards

Provided calibration profiles for pulsars J0304+1932 and J0742-2822

Abstract

This paper defines the mathematical convention adopted to describe an electromagnetic wave and its polarisation state, as implemented in the PSRCHIVE software and represented in the PSRFITS definition. Contrast is made between the convention that has been widely accepted by pulsar astronomers and the IAU/IEEE definitions of the Stokes parameters. The former is adopted as the PSR/IEEE convention, and a set of useful parameters are presented for describing the differences between the PSR/IEEE standard and the conventions (either implicit or explicit) that form part of the design of observatory instrumentation. To aid in the empirical determination of instrumental convention parameters, well-calibrated average polarisation profiles of PSR J0304+1932 and PSR J0742-2822 are presented at radio wavelengths of approximately 10, 20, and 40 cm.