SEE Level 2 XPS Solar Irradiance Data
Download multiple days from the TIMED MDC
XPS Calendar Access: Useful for finding data for a specific day.
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
XPS Data Directory– download any data file
XPS L2 Merged NetCDF file (single file) of the daily XPS L2 data products
XPS Level 2 LISIRD – interactive data access and plotting
Detailed Level 2 XPS Description
README_XPS_L2_012.TXT – information for using XPS_L2 data
The 12 X-Ray Photometers (XP) aboard SEE perform full-disk irradiance measurements of the Sun for about 3 minutes every orbit (97 minutes) which usually gives 14-15 measurements per day. 8 of the XPs produce XUV signals (more info on XP coatings) and one other XP provides a hydrogen Lyman-alpha measurement (121.5 nm). The XPS Level 2 data is time averaged over the entire day, after being 1-AU corrected and removing flares. The 1-AU correction is provided.
| Channel | Coating | Low Wavelength (nm) | High Wavelength (nm) |
|---|---|---|---|
| 1 | Ti/C-14 | 0.10 | 7.00 |
| 2 | Ti/C-10 | 0.10 | 7.00 |
| 3 | Al/Sc/C-24 | 17.00 | 23.00 |
| 5 | Ti/Pd-17 | 0.10 | 10.00 |
| 6 | Ti/Zr/Au-04 | 0.10 | 10.00 |
| 7 | Al/Nb/C-03 | 17.00 | 21.00 |
| 9 | Al/Mn-06 | 0.10 | 7.00 |
| 10 | Cr/Al-07 | 0.10 | 7.00 |
| 11 | Ly-alpha | 121.00 | 122.00 |
After day 205 of 2002 only the green highlighted channels ( 1, 5, & 10) continue to provide XUV signal due to a filter wheel anomaly.
XPS Sensitivity Data from the Bessy calibration
Reading the Data with IDL
With read_netcdf.pro individual data files may be read using an IDL command such as:
read_netcdf,'see__xps_L2_2002022_012_01.ncdf',d,att
The data will then reside in the returned structure “d”, with each tag in the structure defined in the attributes array “att”. Each of the 9 coated diodes used to produce the X-Ray irradiances have a band pass range in the wave array tag.
SEE Level 2 XPS Software
- TIMED-SEE NetCDF README – Described IDL source code and gives examples using read_netcdf.pro and write_netcdf.pro
- read_netcdf.pro – IDL procedure for reading NetCDF files as a structure
- write_netcdf.pro – IDL procedure for writing a data structure (or array of structures) to a NetCDF file
- plotxps_ts.pro – IDL procedure for plotting a time series of XPS Level 2 data.
SEE XPS Solar Irradiance Data Format
Each data file contains an array of structures with 9 elements
XPS_DATA STRUCT = -> Array[9]
Each XPS_DATA structure has the following form:
** Structure <377448>, 14 tags, length=68, data length=64, refs=1: DATE LONG 2002022 CHANNEL INT 1 WAVE FLOAT Array[2] FLUX_MEDIAN FLOAT 0.000875983 DIFF_MA FLOAT -4.73618e-06 ERR_TOT FLOAT 0.163672 ERR_MEAS FLOAT 0.0123417 STDEV_MEAS FLOAT 0.0218227 COR_1AU FLOAT 1.03242 CURRENT FLOAT 0.459073 NUMPT INT 5 COR_DEGRADE FLOAT 1.00000 DEGRADE_MODEL LONG 0 COR_ATMOS STRUCT -> Array[1]
Nested structure COR_ATMOS ** Structure <27a048>, 3 tags, length=12, data length=12, refs=2: AVG FLOAT 0.999966 MIN FLOAT 0.999965 MAX FLOAT 0.999966
NetCDF file attributes for day 2002022
GLOBAL:
Title = SEE Level 2 XPS Data Product - calibrated XPS data averaged over a
day
Source = SEE POC at LASP / CU
Mission = TIMED
Data_product_type = SEE XPS Level 2
Data_product_version = 011
Data_product_revision = 01
Product_format_version = 010
Software_version = 11.01
Software_name = write_netCDF.pro called from xps_level2_main.pro
Calibration_version = 09.01
Description = Calibrated SEE XPS science data averaged over a day $ at
instrument resolution with degradation, atmospheric, and 1AU corrections
History = 10/8/02 DLW Added product_format_version $ 2/17/03 DLW Added
diff_ma.
Filename =
/titus/timed/testing/data/science_dp/level2_xps/xps_L2_2002022_011_01.ncdf
Date_generated = Tue Oct 4 16:36:43 2011
DATE:
Units = YYYY-DOY
Description = Date of observation
CHANNEL:
Units = NONE
Description = Channel index of the 12 XUV Photometers (1-12)
WAVE:
Units = nm
Description = Bandpass wavelength range
FLUX_MEDIAN:
Units = W / m^2
Description = Solar irradiance - median for the day
DIFF_MA:
Units = W / m^2
Description = Difference of median and weighted average solar irradiance over
the day
ERR_TOT:
Units = Fractional
Description = Accuracy of solar irradiance averaged over the day
ERR_MEAS:
Units = Fractional
Description = Measurement precision averaged over the day
STDEV_MEAS:
Units = Fractional
Description = Standard deviation of median for good measurements
COR_1AU:
Units = 1 / (AU^2)
Description = AU correction factor for date
CURRENT:
Units = nanoAmps
Description = Median of Total-Dark-Visible currents from level 1 with FOV
and 1-AU corrections applied
NUMPT:
Units = NONE
Description = Number of measurements used in daily average
COR_DEGRADE:
Units = Fractional
Description = Instrument degradation correction factor
DEGRADE_MODEL:
Units = None
Description = Long value = 1 if degradation function is linearly extrapolated,
0 if linearly interpolated
COR_ATMOS.AVG:
Units = Fractional
Description = Average of atmospheric correction factors
COR_ATMOS.MIN:
Units = Fractional
Description = Minimum of atmospheric correction factors
COR_ATMOS.MAX:
Units = Fractional
Description = Maximum of atmospheric correction factors
