TIMED SEE

SEE Level 3A Solar Irradiance Data

top

Detailed Level 3A Description

README_SEE_L3A_011.TXT - information for using SEE L3A data

SEE Level 3A data files contain each measurements averaged solar irradiance spectrum in 1 nm intervals extracted from the EGS Level 2A and XPS Level 2A data products. Shortward of 27 nm, a solar model is scaled to match the XPS broadband data. SEE Level 3A data files also contain 38 emission lines extracted from EGS Level 2A spectra, and the XPS Level 2A 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 3A data are time averaged over each measurement, after applying corrections for atmospheric absorption, degradation, flare removal, and to 1-AU.

top


Reading the Data with IDL

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

read_netcdf,'see__L3A_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".

top


SEE Level 3A Software

top

SEE Level 3A Solar Irradiance Data Format

Each data file contains an array of structures with 8 elements

L3A_DATA        STRUCT    = ->  Array[8]

Each L3A_DATA structure has the following form:

** Structure <323ac8>, 11 tags, length=4752, data length=4745, refs=1:
DATE LONG 2002039
ODC_ID BYTE 20
START_TIME FLOAT 3292.00
STOP_TIME FLOAT 3452.00
COR_1AU FLOAT 1.02768
EGS_FLARE FLOAT 1.00223
XPS_FLARE FLOAT 1.02361
XPS_TIME FLOAT 0.00000
SP STRUCT -> Array[1]
LINE STRUCT -> Array[1]
XPS STRUCT -> Array[1]

Nested structure SP ** Structure <325c78>, 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 <317fb8>, 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 <325b88>, 3 tags, length=12, data length=12, refs=2:
QS FLOAT 1.00000
AR FLOAT 0.204324
FLARE FLOAT 0.00418555
Nested structure XPS ** Structure <323278>, 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 3A Observation Averaged Data Product - merged XPS and EGS data
Source = SEE POC at LASP / CU
Mission = TIMED
Data_product_type = SEE Level 3A
Data_product_version = 011
Data_product_revision = 01
Product_format_version = 010
Software_version = 11.01
Software_name = write_netCDF.pro called from see_level3a_main.pro
Calibration_version = 09.01
Description = Calibrated SEE EGS and XPS science data averaged over each solar observation at 1nm intervals
History = 9/10/03 Don Woodraska Original creation
Filename = /titus/timed/testing/data/science_dp/level3a/see_L3A_2002039_011_01.ncdf
Date_generated = Wed Sep 12 05:01:12 2012
DATE:
Units = YYYY-DOY
Description = Date of observation
ODC_ID:
Units = none
Description = byte for the observation identifier (1-254)
START_TIME:
Units = seconds of UT day
Description = Observation start times
STOP_TIME:
Units = seconds of UT day
Description = Observation stop times
COR_1AU:
Units = 1 / (AU^2)
Description = AU correction factor for date
EGS_FLARE:
Units = Fraction
Description = mean selected EGS lines ratio to daily median
XPS_FLARE:
Units = Fraction
Description = XPS diode #1 ratio to daily median
XPS_TIME:
Units = seconds of UT day
Description = Time of nearest XPS measurement to the SEE EGS measurement
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 = Observational 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
top

.
 
      NASA SEE TIMED LASP

Revised: November 2007
+ Questions or comments?