There are multiple ways to access the STEREO COR1 data files. One can use the SECCHI Flight (S/C A and B) Images Query Form:
Another method is to access the directory structure for the data from the STEREO Science Center:
The STEREO space weather beacon was envisioned as providing a "browse" tool, and those data can be seen at:
And the Virtual Solar Observatory has links to STEREO and many other ground-based and space-based solar observations:
Software tools and instructions to use all of the STEREO data products are available at:
COR1 User's Guide:


This directory tree contains background images to subtract from the COR1 data to remove scattered light and the F corona. The daily_med directories contain backgrounds for each polarization component derived for each day based on a combination of pixel-by-pixel median and minimum filters. These daily images are then combined over four week periods to form minimum background images, which are recalculated every 10 days and stored in the monthly_min directories. Each directory tree is subdivided by year and month.
Ultimately, these background images will be merged with similar background images for the other SECCHI telescopes, and distributed as part of the SolarSoft DataBase (SSWDB). At that time, users will be able to apply the backgrounds automatically within the SECCHI_PREP program. In the meantime, one can subtract the backgrounds from images prepared using SECCHI_PREP with the /CALFAC_OFF and /CALIMG_OFF keywords.