A Software-Defined Spectral Line Observing System for the DVA1 Telescope

A spectral line observing system for the Dish Verification Antenna 1 (DVA1) telescope at the Dominion Radio Astrophysical Observatory (DRAO) was developed using a software-defined radio (SDR) approach, and is used to observe hydroxyl masers for the purpose of calibrating the telescope's polarization response. A description of the FPGA and software processing pipelines are given, focusing on the digital downconverter (DDC) and software-defined spectrometer. The firmware is implemented on the National Research Council's Kermode FPGA platform, using industry standards for form factor and data transport. Requirements for an upgrade of the John A. Galt 26 m telescope at DRAO are also given, with a description of how the DVA1 backend design will be expanded to meet them.