Effects of NWC transmission for 30–100 and 100–300-keV electron observation data from NOAA satellites. (a) and (b) Electron counts for 1 January to 31 May 2007 with those for 1 August to 31 December 2007 subtracted. The data in each period are the sum of all 30–100- or 100–300-keV electron counts from the medium energy proton and electron detectors (MEPEDs) in the 90° telescopes for the given periods. (c) and (d) Ratio of subtracted data shown above to background electron counts for 1 August to 31 December 2007. The NWC was operating normally from 1 January to 31 May 2007.