Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-08-27
Astrophys.J.Suppl. 138 (2002) 185-218
Astronomy and Astrophysics
Astrophysics
Accepted for publication in Ap. J. Supp. (v. 138 Jan. 2002). 61 pages, 23 figures, expands to 3.8 Mb. Abstract abridged for as
Scientific paper
10.1086/324017
Wavelets are scaleable, oscillatory functions that deviate from zero only within a limited spatial regime and have average value zero. In addition to their use as source characterizers, wavelet functions are rapidly gaining currency within the source detection field. Wavelet-based source detection involves the correlation of scaled wavelet functions with binned, two-dimensional image data. If the chosen wavelet function exhibits the property of vanishing moments, significantly non-zero correlation coefficients will be observed only where there are high-order variations in the data; e.g., they will be observed in the vicinity of sources. In this paper, we describe the mission-independent, wavelet-based source detection algorithm WAVDETECT, part of the CIAO software package. Aspects of our algorithm include: (1) the computation of local, exposure-corrected normalized (i.e. flat-fielded) background maps; (2) the correction for exposure variations within the field-of-view; (3) its applicability within the low-counts regime, as it does not require a minimum number of background counts per pixel for the accurate computation of source detection thresholds; (4) the generation of a source list in a manner that does not depend upon a detailed knowledge of the point spread function (PSF) shape; and (5) error analysis. These features make our algorithm considerably more general than previous methods developed for the analysis of X-ray image data, especially in the low count regime. We demonstrate the algorithm's robustness by applying it to various images.
Freeman Peter E.
Kashyap Vinay
Lamb Donald Q.
Rosner Robert
No associations
LandOfFree
A Wavelet-Based Algorithm for the Spatial Analysis of Poisson Data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Wavelet-Based Algorithm for the Spatial Analysis of Poisson Data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Wavelet-Based Algorithm for the Spatial Analysis of Poisson Data will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-101356