ESP is provided by the University of Southern California (USC). ESP provides calibrations for MEGS sensitivity changes and higher time cadence (0.25-second). The ESP is very similar to the SOHO SEM instrument.
The Euv SpectroPhotometer (ESP) has 9 Si photodiodes behind a transmission grating:
- ESP#1: 34.0-38.1 nm bandpass (Si IX, Si X, Fe XII, Fe XVI, & Mg IX emissions)
- ESP#2: 23.1-27.6 nm bandpass (He II 25.6 nm emission + blend with weaker lines)
- ESP#3: dark photometer to measure particle background (e.g., SEP)
- ESP#4, 5, 6, & 7: 0.1-5.9 nm bandpass, zeroth order light with Ti-C filter, quadrant diodes that gives solar position and also flare location for the larger flares
- ESP#8: 17.2-20.6 nm bandpass (Fe IX, Fe X, Fe XI, & Fe XII emissions)
- ESP#9: 28.0-31.6 nm bandpass (He II 30.4 nm emission + blend with weaker lines)