A High Time Resolution Polarimeter Spectrometer for Radio Astronomy

Abstract

This paper describes a high time resolution radio polarimeter spectrometer based on SAW spectrum analysers. The bandwidth of the prototype instrument is about 30 Xz; time and frequency resolutions of the basic processor are 2.4 us and 650 kHz. Spectra for the Stokes wave polarization parameters are obtainable, allowing complete characterization of incident radiation. The data rate problem usually encountered when SAW chirp Fourier transformers are interfaced to digital post-transformation processors has been overcome with the development of a fast, digital spectrum integrator. This allows the SAW IF processor to work in conjunction with general-purpose computers, giving an observing system with an overall time resolution of around 150 ps. The radiometric efficiency of the new instrumentation compares favourably with that of other radio astronomy spectrometers.