The Laboratory for Atmospheric and Space Physics in Boulder, Colorado created Level 4 data files for the NASA Solar Dynamics Observatory (SDO) Extreme Ultraviolet Variability Experiment (EVE). The Science Processing and Operations Center (SPOC) is responsible for maintaining access to all EVE products.
The level 4 spectra products consist of a model spectrum at a 1-minute cadence, with each product containing 1,440 spectra covering one UTC day. The model spectra are derived from the ESP quadrant diode irradiance and the isothermal plasma temperature from the GOES X-ray channel ratios. These measurements drive a model with components for quiet sun, active region, and flare spectrum contributions. A similar technique was used for TIMED-SEE and SORCE XPS level 4 products that utilized XPS soft x-ray measurements that are analogous to the ESP quadrant diode measurements.