Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

SDO EVE ESP Radiometric Calibration and Results



Leonid Didkovsky, D L. Judge, Seth Wieman, T N. Woods, Phillip Chamberlin, Andrew Jones, Francis Eparvier, Matthew Triplett, Donald Woodraska, D R. McMullin, Mitchell L. Furst, Robert E. Vest


The Solar Dynamics Observatory (SDO) Extreme ultraviolet Solar Photometer (ESP), as a part of the Extreme ultraviolet Variability Experiment (EVE) suite of instruments, was calibrated at the National Institute of Standards and Technology (NIST) on the Synchrotron Ultraviolet Radiation Facility (SURF) Beam Line 2 inFebruary 2007. Precise ESP alignment to the SURF beam was achieved through successive scans in X, Y, Pitch and Yaw, using a comparison of the four channels of ESP's internal quad photodiode as a measure of alignment.The observed alignment between the ESP and the other instruments in the EVE package was found to be in a very good agreement with that measured at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado during ESP/EVE integration. The radiometric calibration of the ESP photometers in the spectral window of around 4.4 nm (central order), and the four first order channels centered at about 18.9, 25.4, 29.8, and 36.1 nm was performed with SURF synchrotron spectra. The position of the SURF beam on the ESP entrance aperture for each energy and current was determined based on modeled quad diode (QD) photometer responses, and real photodiode count-rate data. This determined beam position was later used to obtain exact energy-wavelength-fux profiles for each of the calibration energies and to calculate the quantum efficiency of the ESP channels. The results of this calibration (quantum efficiencies) are compared to the previous ESP NIST calibration results
SPIE Proceedings--The International Society for Optical Engineering


EVE/ESP, NIST/SURF, radiometric calibration, Solar Dynamics Observatory


Didkovsky, L. , Judge, D. , Wieman, S. , Woods, T. , Chamberlin, P. , Jones, A. , Eparvier, F. , Triplett, M. , Woodraska, D. , McMullin, D. , Furst, M. and Vest, R. (2007), SDO EVE ESP Radiometric Calibration and Results, SPIE Proceedings--The International Society for Optical Engineering, [online],, (Accessed May 30, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created September 12, 2007, Updated October 12, 2021