I am wondering if it would be straightforward to provide a "footprint" outline of the Stripe 82 area on the sky for use in highly zoomed-out context images in PDAC.

If this is an easy task, in what format would we need to specify the coordinates of the online?

I think we can do a calculation of four corners of all the coadded images and produce a sd9 region file for the outline.

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How to generate the region files attached here:

1)Get four corners data for all the coadds FOVs for SDSS:
curl -o sdssFourCorners.json -d 'query=SELECT+corner1Ra,corner1Decl,corner2Ra,corner2Decl,corner3Ra,corner3Decl,corner4Ra,corner4Decl+FROM+sdss_stripe82_00.DeepCoadd;' http://lsst-qserv-dax01.ncsa.illinois.edu:5000/db/v0/tap/sync
2)Convert the json file to csv using a tool on line:
http://www.convertcsv.com/json-to-csv.htm
3)Sort the csv file by corner1Ra
4)Remove "^M"
5)Convert the csv file to a region file by adding "polygon(" and ") #color=green" and a header "fk5"
6)For only plot 1% or 10% FOVs:
awk 'NR == 1 || NR % 100 == 0' input.reg > output_1pct.reg
awk 'NR == 1 || NR % 10 == 0' input.reg > output_10pct.reg

The region file can be loaded to Firefly.