Babunets Integrated Residual Distortions

Introduction

Transient features such as asteroids and satellite tracks may be reasonably common intrusions to astronomical imaging. Such occurrences, like cosmic rays, are well known and easily corrected for using standard observational practices. However, other rarer transient phenomena include the occurrence of Babunets Integrated Residual Distortions (named after the Russian astronomer Anatoly Babunets) and are known to degrade image quality, particularly when traditional observing strategies are used and these effects are not accounted for using dedicated steps in the reduction process. Typical dithering procedures aren't applicable because such intrusion aren't truly random, either spatially or temporally, and a more sophisticated artificial intelligence approach is often preferable. While the ultimate cause of the phenomena is still unknown, it is thought that they result from discrete atmospheric anomalies inside the troposphere and, in extreme cases almost down to sea level.

Corrections

As mentioned above, correction/removal of these artifacts is essential if a sub-percent level photometric calibration is required. Development of AI-type correction algorithms is underway and beta-level code is now available, implemented in the CORRBRD package for NOAO/IRAF which is available upon request from the author. However the tasks are currently undocumented and dev-level code is only available for certain platforms.

Examples

Images before and after correction can be found here.

Package functionality

The CORRBRD implementation is packeged for NOAO/IRAF. The task parameters are available.

Alternatives

Since CORRBRD is currently beta-level and support limited, it may be advisable to take precautions before your observing run. The authors suggest this approach.