HOMER tagInfo metrics for ATAC-seq

Question

[shankasal]

I'm trying to make sense of all of the parts of the tagInfo.txt metrics that HOMER spits out during makeTagDirectory for a sam file from ATAC-seq. The one I really can't find much information on is peakSizeEstimate. I'd like to know how this is determined and what causes the program to give two different estimates when the fragmentLengthEstimate is very similar. Moreover, what does it mean for the quality of ATAC-seq data when HOMER determines one sequencing file to have a peakSizeEstimate of say 57 versus another having a peakSizeEstimate of 300.