TIMED/SEE Diode Irradiance - Level 3A XPS
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 3A data is time averaged irradiance from each solar photodiode over the 3-minute exposure each orbit, after being 1-AU corrected. Flares are not removed from this product. This data set contains broadband irradiances 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.