We note that the background does depend upon the location of the spacecraft with respect to the particle belts and with respect to the magnetopause (Kuntz & Snowden in prep). Although these results will not be fully exploited in this version of ESAS, if there are issues with the MOS QPB seeming to be over- or under-subtracted at lower energies, it is worthwhile to check to see how close to the particle belts the observation was made.
