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Chapter 5

Instrumentation for Pulsar Observations

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Figures
Further Reading
Available Resources

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Pulsar observations place higher demands on data acquisition systems than most other astronomical observations. High time resolution is necessary to search for millisecond and rapidly rotating pulsars (Chapter 6), to resolve microsecond and nanosecond scale structure in individual pulses (Chapter 7) and to obtain high-precision arrival times (Chapter 8). Since pulsars are generally weak sources, observations covering a wide bandwidth are desirable to maximise sensitivity. As discussed in Chapter 4, the frequency-dependent refractive index of the interstellar medium means that pulses emitted at higher radio frequencies travel faster and arrive earlier than those emitted at lower frequencies. For a finite receiver bandwidth, this dispersion process broadens the pulse so that its signal to noise ratio (S/N) is reduced. Frequency resolution therefore is vital to combat the effects of dispersion. We distinguish between two main approaches to de-dispersion: (a) incoherent devices (filterbanks and correlators) where the phase content of the signal is not recorded; (b) coherent devices (baseband recorders and coherent de-dispersers) which make full use of the incoming signal to properly recover the true pulse shape.

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Further Reading

Available Resources

EPN Format
Reference:
Lorimer et al (1998)
EPN Database - The European Pulsar Network Data Archive. Display and download EPN and ASCII data files and display GIF images of pulse profiles over different wavelengths.

PSRFITS
Reference: Hotan, van Straten & Manchester (2004)
PSRFITS definitions at CSIRO.

SIGPROC
Reference: Lorimer (2001), Arecibo Technical Memo #2001-01
SIGPROC on Duncan Lorimer's homepage.

PRESTO
Homepage
Reference: Ransom, S. M. (2001) - PhD Thesis, Harvard University
Contact Scott Ransom for details on using PRESTO for publications.

PSRCHIVE
Reference: Hotan, van Straten & Manchester (2004)

 
Last updated 12:44 24/11/2004