6 research outputs found
Digital Complex Correlator for a C-band Polarimetry survey
The international Galactic Emission Mapping project aims to map and
characterize the polarization field of the Milky Way. In Portugal it will
cartograph the C-band sky polarized emission of the Northern Hemisphere and
provide templates for map calibration and foreground control of microwave space
probes like ESA Planck Surveyor mission. The receiver system is equipped with a
novel receiver with a full digital back-end using an Altera Field Programmable
Gate Array, having a very favorable cost/performance relation. This new digital
backend comprises a base-band complex cross-correlator outputting the four
Stokes parameters of the incoming polarized radiation. In this document we
describe the design and implementation of the complex correlator using COTS
components and a processing FPGA, detailing the method applied in the several
algorithm stages and suitable for large sky area surveys.Comment: 15 pages, 10 figures; submitted to Experimental Astronomy, Springe
Accelerating software radio astronomy FX correlation with GPU and FPGA co-processors
Includes abstract.Includes bibliographical references (leaves [117]-121).This thesis attempts to accelerate compute intensive sections of a frequency domain radio astronomy correlator using dedicated co-processors. Two co-processor implementations were made independently with one using reconfigurable hardware (Xilinx Virtex 4LXlOO) and the other uses a graphics processor (Nvidia 9800GT). The objective of a radio astronomy correlator is to compute the complex valued correlation products for each baseline which can be used to reconstruct the sky's radio brightness distribution. Radio astronomy correlators have huge computation demands and this dissertation focuses on the computational aspects of correlation, concentrating on the X-engine stage of the correlator