TIMED SEE

SEE Level 3 Solar Irradiance Data

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Detailed Level 3 Description

README_SEE_L3_011.TXT - information for using SEE L3 data

SEE Level 3 data files contain one daily averaged solar irradiance spectrum in 1 nm intervals extracted from the EGS Level 2 and XPS Level 2 data products. Shortward of 27 nm, a solar model is scaled to match the XPS broadband data. SEE Level 3 data files also contain 38 emission lines extracted from EGS Level 2 spectra, and the XPS Level 2 diode irradiances.

For normal operations, SEE observes the Sun for about 3 minutes every orbit (97 minutes), which usually gives 14-15 measurements per day. The SEE Level 3 data are time averaged over the entire day, after applying corrections for atmospheric absorption, degradation, flare removal, and to 1-AU.

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Reading the Data with IDL

With read_netcdf.pro individual data files may be read using an IDL command such as:

read_netcdf,'see__L3_2002044_005_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".

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SEE Level 3 Software

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SEE Level 3 Solar Irradiance Data Format

Each data file contains an array of structures with 1 elements

L3_DATA         STRUCT    = ->  Array[1]

Each L3_DATA structure has the following form:

** Structure <326918>, 7 tags, length=4736, data length=4728, refs=1:
DATE LONG 2002039
EGS_DEGRADE_MODEL
INT 0
XPS_DEGRADE_MODEL
INT 0
COR_1AU FLOAT 1.02768
SP STRUCT -> Array[1]
LINE STRUCT -> Array[1]
XPS STRUCT -> Array[1]

Nested structure SP ** Structure <324a18>, 4 tags, length=3120, data length=3120, refs=2:
WAVE FLOAT Array[195]
FLUX FLOAT Array[195]
ERR_TOT FLOAT Array[195]
ERR_MEAS FLOAT Array[195]
Nested structure LINE ** Structure <587988>, 6 tags, length=1368, data length=1368, refs=2:
WAVE FLOAT Array[38]
FLUX FLOAT Array[38]
ERR_TOT FLOAT Array[38]
ERR_MEAS FLOAT Array[38]
NAME STRING Array[38]
LOGT FLOAT Array[38]
Nested structure XPS_SF ** Structure <587898>, 3 tags, length=12, data length=12, refs=2:
QS FLOAT 1.00000
AR FLOAT 0.204324
FLARE FLOAT 0.00240766
Nested structure XPS ** Structure <326008>, 7 tags, length=228, data length=228, refs=2:
WAVE_XPS_1 FLOAT Array[9]
WAVE_XPS_2 FLOAT Array[9]
FLUX FLOAT Array[9]
ERR_TOT FLOAT Array[9]
ERR_MEAS FLOAT Array[9]
CURRENT FLOAT Array[9]
XPS_SF STRUCT -> Array[1]

NetCDF file attributes for day 2002039

GLOBAL:

Title = SEE Level 3 Final Data Product - merged daily XPS and EGS data
Source = SEE POC at LASP / CU
Mission = TIMED
Data_product_type = SEE Level 3
Data_product_version = 011
Data_product_revision = 01
Product_format_version = 010
Software_version = 11.01
Software_name = write_netCDF.pro called from see_level3_main.pro
Calibration_version = 09.01
Description = Calibrated SEE EGS and XPS science data averaged over a day at 1nm intervals
History = 10/08/02 Don Woodraska Added product_format_version.
Filename = /titus/timed/testing/data/science_dp/level3/see_L3_2002039_011_01.ncdf
Date_generated = Wed Sep 12 05:01:12 2012
DATE:
Units = YYYY-DOY
Description = Date of observation
EGS_DEGRADE_MODEL:
Units = None
Description = Long value is 1 if degradation function is linearly extrapolated, 0 if linearly interpolated
XPS_DEGRADE_MODEL:
Units = None
Description = Long value is 1 if degradation function is linearly extrapolated, 0 if linearly interpolated
COR_1AU:
Units = 1 / (AU^2)
Description = AU correction factor for date
SP.WAVE:
Units = nm
Description = 1nm bins at center of wavelength bin (half-integral)
SP.FLUX:
Units = W / m^2 / nm
Description = Merged Solar irradiance for XPS and EGS flux at 1nm bins with gaps filled using Woods-Rottman 2002 VUV model. Below 26 nm, flux is result of solution of linear equations involving XPS diodes and scaled to the VUV model. EGS data is used above 26 nm except 114.5-120.5 and 122.5-128.5 nm where the VUV model is scaled to the EGS Lyman-alpha line.
SP.ERR_TOT:
Units = Fractional
Description = Accuracy of solar irradiance
SP.ERR_MEAS:
Units = Fractional
Description = Measurement precision
LINE.WAVE:
Units = nm
Description = Reference wavelengths for spectral lines
LINE.FLUX:
Units = W / m^2
Description = Integrated spectral line irradiance
LINE.ERR_TOT:
Units = Fractional
Description = Accuracy of spectral line irradiance
LINE.ERR_MEAS:
Units = Fractional
Description = Measurement precision of spectral line irradiance
LINE.NAME:
Units = None
Description = Text indicating the largest contribution to spectral line
LINE.LOGT:
Units = None
Description = Logarithm of Temperature for spectral line
XPS.WAVE_XPS_1:
Units = nm
Description = Lower limit for XPS diode bandpass filter
XPS.WAVE_XPS_2:
Units = nm
Description = Upper limit for XPS diode bandpass filter
XPS.FLUX:
Units = W / m^2
Description = Daily median flux for the diode (Level 2)
XPS.ERR_TOT:
Units = Fractional
Description = Accuracy of XPS level 2 irradiance
XPS.ERR_MEAS:
Units = Fractional
Description = Measured uncertainty in XPS level 2 irradiance
XPS.CURRENT:
Units = nanoAmps
Description = Median of Total-Dark-Visible currents from level 1 with FOV and 1-AU corrections
XPS.XPS_SF.QS:
Units = None
Description = Scalefactor from XPS Level 4 model for daily Quiet Sun component
XPS.XPS_SF.AR:
Units = Nanometers
Description = Scalefactor from XPS Level 4 model for daily Active Region component
XPS.XPS_SF.FLARE:
Units = Fractional
Description = Scalefactor from XPS Level 4 model for flare component
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      NASA SEE TIMED LASP

Revised: November 2007
+ Questions or comments?