TIMED/SEE Diode Irradiance - Level 2 XPS (Daily)

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Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) / Solar EUV Experiment (SEE) Solar Broadband Irradiance - Daily Average

The TIMED/SEE X-ray ultraviolet (XUV) Photometer System (XPS) has been providing solar irradiance products since January 2002. The XPS is a collection os 12 silicon photodiodes with various metallic thin film coatings deposited directly on the diodes to limit the bandpasses. The XPS Level 2 data is time averaged irradiance from each solar photodiode over the entire day after being 1-AU corrected and removing flares. This data set contains daily averaged broadband irradiance from about 0.1-7 nm.

Around July 24, 2002, the XPS filter wheel had an anomaly and became stuck in one position, restricting the solar measurements to only diode numbers 1, 5, and 10. Diode 1 is sensitive to 0.1-7 nm, diode 5 is sensitive to 0.1-10 nm, and diode 10 is very similar to diode 1. Over time, the diode 5 and 10 measurements have become difficult to process due to filter degradation and electronic drift. Only diode 1 provides high quality irradiance measurements over the full mission. The solar irradiance from 6-37 nm is measured spectrally at 10 second cadence continuously by SDO/EVE since May 2010. A very similar XPS instrument on the SORCE satellite is also available, and another similar broadband measurement continues on SDO/EVE ESP continuously at 4 Hz.

For FTP access to individual files visit the SEE Main Data Page.