Tuesday, June 22, 2010

EVE Data Release

The Version 1 official calibrated products are now available effective June 18, 2010. We currently support only expert access directly to the files. A graphical tool that supports searching will soon be available. EVE has been making solar measurements since March 26, 2010. Normal operations began on May 1, 2010.

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.