Optimal and Efficient Streak Detection in Astronomical Images
Identification of linear features (streaks) in astronomical images is important for several reasons, including: detecting fast-moving near-Earth asteroids; detecting or flagging faint satellites streaks; and flagging or removing diffraction spikes, pixel bleeding, line-like cosmic rays and bad-pixel...
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Published in | The Astronomical journal Vol. 156; no. 5; pp. 229 - 241 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Madison
The American Astronomical Society
01.11.2018
IOP Publishing |
Subjects | |
Online Access | Get full text |
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Summary: | Identification of linear features (streaks) in astronomical images is important for several reasons, including: detecting fast-moving near-Earth asteroids; detecting or flagging faint satellites streaks; and flagging or removing diffraction spikes, pixel bleeding, line-like cosmic rays and bad-pixel features. Here we discuss an efficient and optimal algorithm for the detection of such streaks. The optimal method to detect streaks in astronomical images is by cross-correlating the image with a template of a line broadened by the point-spread function of the system. To do so efficiently, the cross-correlation of the streak position and angle is performed using the Radon transform, which is the integral of pixel values along all possible lines through an image. A fast version of the Radon transform exists, which we here extend to efficiently detect arbitrarily short lines. While the brute force Radon transform requires operations for a N × N image, the fast Radon transform has a complexity of . We apply this method to simulated images, recovering the theoretical signal-to-noise ratio, and to real images, finding long streaks of low-Earth-orbit satellites and shorter streaks of Global Positioning System satellites. We detect streaks that are barely visible to the eye, out of hundreds of images, without a-priori knowledge of the streaks' positions or angles. We provide implementation of this algorithm in Python and MATLAB. |
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Bibliography: | Instrumentation, Software, Laboratory Astrophysics, and Data AAS11768 |
ISSN: | 0004-6256 1538-3881 |
DOI: | 10.3847/1538-3881/aaddff |