The ami_average step is one of the AMI-specific steps in the ami sub-package and is part of Stage 3 calwebb_ami3 processing. It averages the results of LG processing from the ami_analyze step for multiple exposures of a given target. It computes a simple average for all 8 components of the “ami” product files from all input exposures.

For a given association of exposures, the “ami” products created by the ami_analyze step may have fit_image and resid_image images that vary in size from one exposure to another. If this is the case, the smallest image size of all the input products is used for the averaged product and the averaged fit_image and resid_image images are created by trimming extra rows/columns from the edges of images that are larger.


The ami_average step does not have any step-specific arguments.


LG model parameters

Data model


File suffix


The only input to the ami_average step is a list of one or more “ami” files to be processed. These should be output files from the ami_analyze step. The input to the step must be in the form of a list of “ami” file names. Passing data models or ASN files is not supported at this time. Use the calwebb_ami3 pipeline to conveniently process multiple inputs.


Average LG model parameters

Data model


File suffix

_amiavg or _psf-amiavg

The ami_average step produces a single output file, having the same format as the input files, where the data for the 8 file components are the averages from the list of input files. If the inputs in the ASN file are designated as “science”, the output product type will be “_amiavg”, whereas if the inputs are designated as “psf”, the output product type will be “_psf-amiavg.” The output file name syntax is source-based, using the product name specified in the input ASN file, e.g. “jw87600-a3001_t001_niriss_f480m-nrm_amiavg.fits.”

Reference Files

The ami_average step does not use any reference files.