high-level ska signal processing description - The Square Kilometre ...

10 Pulsar Search
WP2‐040.030.010‐TD‐001
Revision : 1
SKA Memo 125 provides has identified two major science goals that are to drive the technical
specifications for the SKA1. One of these is:
‘Detecting and timing binary pulsars and spin‐stable millisecond pulsars in order to test theories of
gravity (including General Relativity and quantum gravity), to discover gravitational waves from
cosmological sources, and to determine the equation of state of nuclear matter.’
10.1 Binary Search
The detection of binary pulsar systems as part of a pulsar search requires algorithms that are
capable of compensating for loss of sensitivity caused by the pulsar’s elliptical orbital motion as a
result of the Doppler component.
Ralph Eatough’s 2009 PhD thesis [43] provides an overview of the common time and frequency
domain techniques that have been developed to compensate for the effects of pulsar orbital motion
and are represented in Figure 11. Non binary systems can be considered as a special case where the
Doppler component is zero.
bdd [block] system [Binary search definitions]
«block»
Binary Search
«block»
Matched
Filter
«block»
Stack Search
«block»
Coherence
Recovery
«block»
Hough
Transform
«block»
Phase
Search
«block»
Time Domain
Resampling
Figure 11 Binary Pulsar Search Algorithms
A brief overview of each technique is provided in the following sections.
10.1.1 Matched Filter
An alternative method of conducting "constant acceleration" searches uses complex matched
filtering in the Fourier domain as opposed to re‐sampling of the de‐dispersed time series. The local
(meaning only those near the Fourier frequency of interest) complex Fourier amplitudes from the
2011‐03‐29 Page 44 of 59