README file for:
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TIMED SEE XPS Level 2 Data Products
This README file is located at:
https://lasp.colorado.edu/data/timed_see/level2_xps/README_XPS_L2_011.TXT
Also read the SEE_v11_releasenotes.txt file for known issues
with the SEE data available at:
https://lasp.colorado.edu/data/timed_see/SEE_v11_releasenotes.txt
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TIMED Data Rules of the Road & Data Access Policy
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Users of TIMED data are asked to respect the following
guidelines
Mission scientific and model results are open to all.
Users should contact the PI or designated team member of an
instrument or modeling group early in an analysis project
to discuss the appropriate use of instrument data or model
results. This applies to TIMED mission team members, guest
investigators, and other members of the scientific
community or general public.
Users that wish to publish the results derived from TIMED
data should normally offer co-authorship to the PI or
his/her designated team member. Co-authorship may be
declined. Appropriate acknowledgement to institutions,
personnel, and funding agencies should be given.
Users should heed the caveats of investigators as to the
interpretation and limitations of data or model results.
Investigators supplying data or models may insist that such
caveats be published, even if co-authorship is declined.
Data and model version numbers should also be specified
Pre-prints of publications and conference abstracts should
be widely distributed to interested parties within the
mission and related projects.
See also: http://www.timed.jhuapl.edu/scripts/mdc_rules.pl
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TIMED SEE XPS Level 2 Data Product
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XPS OVERVIEW: The XUV Photometer System (XPS) contains 12
Si photodiodes for measuring the solar XUV (0-34 nm)
irradiance and also the hydrogen Lyman-alpha (121.6 nm)
emission. 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 2 data are
time averaged over the entire day, after applying
corrections for atmospheric absorption, degradation, flare
removal, and to 1-AU. There are redundant channels to
provide weekly in-flight relative calibrations, and there
is also a suborbital (sounding rocket) payload that is
flown once a year for TIMED SEE absolute calibrations.
The first SEE suborbital calibration flight was
on Feb. 8, 2002, the second was on Aug. 12, 2003, the third was
on Oct. 15, 2004, the fourth was on Oct. 28, 2006, and the final
SEE calibration flight was on Apr. 14, 2008. There are also three
SDO EVE calibration flights used for checking SEE degradation trends -
May 3, 2010, Mar. 23, 2011, and June 23, 2012.
The XPS filter wheel had an anomaly on day 2002/205
whereby it became fixed in position 6. The only solar
measurements since then are from XP channels 1 (0-7 nm),
5 (0-10 nm), and 10 (0-7 nm). The spectral gap between
10-27 nm will be filled for SEE Level 3 data products using
a model of the solar XUV irradiance based on the historical
XPS data. The SORCE XPS, almost identical to the
TIMED SEE XPS, was launched in Jan. 2003 and continues
the full spectral coverage of the XUV range starting in March
2003. Details of the instrument can be found at
https://lasp.colorado.edu/see/overview/instrument-overview
DATA LOCATION: SEE FTP site at
https://lasp.colorado.edu/data/timed_see/level2_xps/
Copy the *.ncdf files as BINARY files.
Copy the *.pro files (IDL procedures) as ASCII files.
Copy the *.txt files (help files) as ASCII files.
A special mission-to-date merged file is created from this data
and updated daily. The most recent file may be located at:
https://lasp.colorado.edu/data/timed_see/level2_xps/
with a naming convention of see__xps_L2_merged_YYYYDOY_011.ncdf
FILE FORMAT: NetCDF file for each daily average
FILE CONTENT: Solar irradiances from the 9 UV channels at
instrument resolution (~ 7 nm)
CURRENT VERSION: 11 (released 10/12)
WARNINGS: The XPS channel #3 data should not be used.
See SEE_v11_releasenotes.txt for more information.
READING A FILE:
You can use the IDL procedure read_netcdf.pro to read the
SEE data products (or almost any NetCDF file). Example
usage follows.
IDL> read_netcdf,'see__xps_L2_2002022_011_02.ncdf',d,att
where
d = data read from the specified file
att = string array listing the attributes (definitions)
IDL> help, d, /structure ; to list data structure
IDL> n = n_elements(att) ; to print attributes
IDL> for k=0,n-1 do print, att[k]
read_netcdf.pro can be found at
https://lasp.colorado.edu/data/timed_see/code/software/idl/netCDF/read_netcdf.pro
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Special Software for XPS Level 2 Data Products
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PLOTXPS_TS.PRO
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This procedure will plot the time series (TS) for a
specified XPS channel (1-12). Channels 4, 8, and 12 are
not included in the XPS Level 2 product as they only
provide the visible light calibration for the UV channels.
USAGE:
IDL> plotxps_ts, 1, /merged ; to use the "xps_L2_merged.ncdf"
; file instead of reading all the daily files
; and then to plot TS of XPS channel #1
IDL> plotxps_ts, 2 ; to plot TS of XPS channel #2
IDL> plotxps_ts, 7, data ; to get TS data for XP #7
plotxps_ts can be found at
https://lasp.colorado.edu/data/timed_see/level2_xps/plotxps_ts.pro
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Version History for XPS Level 2 Data Product
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1.00 Pre-launch test version
2.00 Pre-launch revised test version
3.00 12/01 Early-operation version
4.00 5/02 First public version. Updated with
corrections for the sensitivity related to the rocket
calibration results, updated FOV maps, degradation (none
found), atmospheric absorption (essentially none), and to 1
AU. XP channel #3 has FOV problems and should not be used.
5.00 9/02 Second public version. Updated with algorithms to
handle the XPS filter wheel being fixed in position 6 since
day 2002/205. Also updated processing of the XP channel #10
to be the 28-34 nm irradiance, which are considered preliminary
and not fully validated. XP channel #3 still has FOV problems
and should not be used.
6.00 3/03 See SEE_v6_releasenotes.txt for information.
7.00 7/04 See SEE_v7_releasenotes.txt for information.
8.00 6/05 See SEE_v8_releasenotes.txt for information.
9.00 4/07 See SEE_v9_releasenotes.txt for information.
10.00 7/09 See SEE_v10_releasenotes.txt for information.
11.00 10/12 See SEE_v11_releasenotes.txt for information.
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The main SEE web page is: http://lasp.colorado.edu/see
For SEE data access problems or suggestions, you can send
e-mail to don.woodraska@lasp.colorado.edu or
tom.woods@lasp.colorado.edu
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END OF README FILE