|Operator / Installation / Operator - Instrument Team Request Instructions||Algorithm Hierarchy|
An Automated Image Rejection (AIR) program for image Quality Assurance (QA) has been developed for use in processing GONG+ data. It includes checks for detecting bad images due to thin or partial cloudiness, obstructions in the field of view (e.g. low altitude aircraft at Big Bear), and abnormal instrument operation. Data from a test period were reprocessed through our image calibration pipeline using the AIR program for image QA decisions. The dataset produced with AIR had a slightly higher duty cycle than the archived data. Comparison of the resulting l-nu diagrams, peak mode-frequency distributions, and flow maps derived from ring diagrams show good agreement with the archived data products.
The current QA process for the GONG+ image calibration and processing pipeline requires much human interaction. AIR was developed to automate the bulk of this QA task. The goals for this program include:
reducing the level of human interaction needed to process data
use objective, repeatable criteria for image selection/rejection
to improve duty cycle
Image quality tests performed by AIR include
checks of instrument status keyword values in the FITS file header of each image to verify the instrument is configured for normal data collection and is operating properly
checks for active tracking and image stability
checks for image signal and noise levels
checks for large temporal variations between images.
To download the PDF version of the entire AIR document click here