Level 1 Product Overview:
The ESP Level 1 irradiance data are fully calibrated and corrected for particle background, visible light leakage, degradation in sensitivity, and spacecraft location (corrected to 1‐AU).
A suborbital sounding rocket payload is flown once a year for EVE absolute calibrations. The first suborbital flight after the launch of SDO was on May 3, 2010. Daily on‐orbit calibrations are performed to track changes in detector dark current, filter condition, and electrometer gain.
Each data file covers a time span of 24 hours with 4 measurement/sec cadence. Level 1 data is available with 1 day latency.
Level 2 Product Overview:
There are 2 types of EVE level 2 products: Spectra (EVS) and Lines (EVL). Level 2 spectra are the merged spectral measurements from the two spectrographs, A and B. The A detector is designed to measure from 6‐17 nm, and 16‐38 nm using two filters, while the B detector is designed to measure 35‐105 nm. Level 2 processing stitches these pieces to form one spectrum.
Lines are integrated from low to high bounds, and the 4 Hz photometer data are averaged down to the same time scale as the spectrum. No continuum is subtracted from the line irradiances.
