Optimal placement of a limited number of observations for period searches

• Main Authors: Saunders, Eric S, Naylor, Tim, Allan, Alasdair
• Format: Journal Article
• Language: English
• Published: 17-05-2006
• Subjects: Physics - Astrophysics of Galaxies; Physics - Cosmology and Nongalactic Astrophysics; Physics - Earth and Planetary Astrophysics; Physics - High Energy Astrophysical Phenomena; Physics - Instrumentation and Methods for Astrophysics; Physics - Solar and Stellar Astrophysics
• DOI: 10.48550/arxiv.astro-ph/0605421

Robotic telescopes present the opportunity for the sparse temporal placement
of observations when period searching. We address the best way to place a
limited number of observations to cover the dynamic range of frequencies
required by an observer. We show that an observation distribution geometrically
spaced in time can minimise aliasing effects arising from sparse sampling,
substantially improving signal detection quality. The base of the geometric
series is however a critical factor in the overall success of this strategy.
Further, we show that for such an optimal distribution observations may be
reordered, as long as the distribution of spacings is preserved, with almost no
loss of quality. This implies that optimal observing strategies can retain
significant flexibility in the face of scheduling constraints, by providing
scope for on-the-fly adaptation. Finally, we present optimal geometric
samplings for a wide range of common observing scenarios, with an emphasis on
practical application by the observer at the telescope. Such a sampling
represents the best practical empirical solution to the undersampling problem
that we are aware of. The technique has applications to robotic telescope and
satellite observing strategies, where target acquisition overheads mean that a
greater total target exposure time (and hence signal-to-noise) can often in
practice be achieved by limiting the number of observations.