SEE Level 2 EGS Solar Irradiance Data
Download multiple days from the TIMED MDC
EGS 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
EGS Data Directory– download any data file
EGS L2 Merged NetCDF file (single file) of the daily EGS L2 data products
EGS Level 2 LISIRD – interactive data access and plotting
Detailed Level 2 EGS Description
README_EGS_L2_012.TXT – information for using EGS_L2 data
The EUV Grating Spectrograph (EGS) aboard SEE performs measurements of the Sun for about 3 minutes every orbit (97 minutes) which usually gives 14-15 measurements per day. The Level 2 data is time averaged over the entire day, after being 1-AU corrected and removing flares. The 1-AU correction is provided.
Reading the Data with IDL
With read_netcdf.pro individual data files may be read using an IDL command such as:
read_netcdf,'see__egs_L2_2002044_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”.
SEE Level 2 EGS 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
- plotegs_ts.pro – IDL procedure for plotting a time series of EGS Level 2 data.
- plotegs_sp.pro – IDL procedure for plotting a daily averaged spectrum from one EGS Level 2 data file.
SEE Level 2 EGS Solar Irradiance Data Format
Each data file contains a structure with 1 elements
EGS_DATA STRUCT = -> Array[1]
The EGS_DATA structure has the following form:
** Structure <281ec8>, 14 tags, length=98032, data length=98032, refs=1: DATE LONG 2002039 WAVE FLOAT Array[1690] FLUX_MEDIAN FLOAT Array[1690] DIFF_MA FLOAT Array[1690] ERR_TOT FLOAT Array[1690] ERR_MEAS FLOAT Array[1690] STDEV_MEAS FLOAT Array[1690] NUMPT INT Array[1690] COR_1AU FLOAT 1.02768 COR_OS_MED FLOAT Array[1690] COR_OS_AVG FLOAT Array[1690] DEGRADE_MODEL LONG 0 COR_ATMOS STRUCT -> Array[1] COR_DEGRADE STRUCT -> Array[1]
Nested structure COR_ATMOS ** Structure <27a2d8>, 3 tags, length=20280, data length=20280, refs=2: AVG FLOAT Array[1690] MIN FLOAT Array[1690] MAX FLOAT Array[1690]
Nested structure COR_DEGRADE ** Structure <2f28f8>, 3 tags, length=20280, data length=20280, refs=2: AVG FLOAT Array[1690] MIN FLOAT Array[1690] MAX FLOAT Array[1690]
NetCDF file attributes for day 2002039
GLOBAL:
Title = SEE Level 2 EGS Data Product - calibrated 0.1nm EGS data averaged
over a day
Source = SEE POC at LASP / CU
Mission = TIMED
Data_product_type = SEE EGS Level 2
Data_product_version = 011
Data_product_revision = 02
Product_format_version = 010
Software_version = 11.01
Software_name = write_netCDF.pro called from egs_level2_main.pro
Calibration_version = 09.01
Description = Calibrated SEE EGS science data averaged over a day $ at 0.1
nm bins with degradation, atmospheric, and 1AU corrections
History = 10/8/02 Don Woodraska Added product_format_version. $ 1/28/03 Don
Woodraska Added order sorting corrections. $
Filename =
/titus/timed/testing/data/science_dp/level2_egs/egs_L2_2002039_011_02.ncdf
Date_generated = Tue Sep 11 19:41:02 2012
DATE:
Units = YYYY-DOY
Description = Date of observation
WAVE:
Units = nm
Description = Array of wavelength intervals, half-Angstrom centers
FLUX_MEDIAN:
Units = W / m^2 / nm
Description = Array of median solar irradiances for each wavelength interval.
This is the spectrum
DIFF_MA:
Units = W / m^2 / nm
Description = Array of differences between the median and weighted averaged
solar irradiances for each wavelength interval
ERR_TOT:
Units = Fractional
Description = Accuracy of solar irradiance
ERR_MEAS:
Units = Fractional
Description = Measurement precision
STDEV_MEAS:
Units = Fractional
Description = Standard deviation of the median
NUMPT:
Units = NONE
Description = Array of the Number of points (1-Angstrom-gridded measurements)
used in determining the daily average for each wavelength interval
COR_1AU:
Units = 1 / (AU^2)
Description = AU correction factor for date
COR_OS_MED:
Units = W/m^2/nm
Description = Order Sorting correction applied to flux_median
COR_OS_AVG:
Units = W/m^2/nm
Description = Order Sorting correction applied to weighted avg irradiance
DEGRADE_MODEL:
Units = None
Description = Long value = 1 if degradation function is linearly extrapolated,
0 if linearly interpolated
COR_ATMOS.AVG:
Units = Fractional
Description = Array of Averaged atmospheric correction factors for each
wavelength interval
COR_ATMOS.MIN:
Units = Fractional
Description = Array of Minimum atmospheric correction factors
COR_ATMOS.MAX:
Units = Fractional
Description = Array of Maximum atmospheric correction factors
COR_DEGRADE.AVG:
Units = Fractional
Description = Array of Average instrument degradation correction factors
COR_DEGRADE.MIN:
Units = Fractional
Description = Array of Minimum instrument degradation correction factors
COR_DEGRADE.MAX:
Units = Fractional
Description = Array of Maximum instrument degradation correction factors