SWS TUTORIAL: pipeline

SWS TUTORIAL

SWS Pipeline

SWS Data Reduction Software:
There are two standard software packages to reduce SWS observations from telemetry data to standard output products (ERD, SPD, AAR):
OLP/pipeline:

OLP = Off-Line Processing ("pipeline")
standard product generation from telemetry data
used by ISO SOC for standard processing (=> CD-roms)
used at SWS data centres for reprocessing
some modules are still insufficient (antimem, updowncal)
some tasks are difficult to automize (e.g. glitch/tial removal)
some tasks are not covered (like flatfielding, smoothing)
=> still some work to be done by observer:
AAR is not in any case the final product!

SIA/OSIA:

SIA = SWS Interactive Analysis
contains pipeline modules as a subset
step-by-step processing possible
interactive substitutes for several pipeline modules
flexible calibration file access
post-AAR processing with SIA or ISAP
client-server sytem with overnight update
available for visitors of SWS data centres
OSIA = Open SIA:
frozen subset of SIA
contains the tools to (re-)derive AAR from ERD
post-AAR processing with ISAP
will be publically available via FTP soon (Sep. 98 ?)
please check ISOSDC web pages for up-to-date info

In this section the individual reduction steps of the SWS pipeline are discussed. As observers usually run O/SIA but have no access to OLP, the pipeline modules are presented here as they are contained in the O/SIA environment. In the following text just the term SIA is used, but the statements hold, unless explicitly mentioned, also for OSIA.
To execute the described commands, some basic IA (+IDL) knowledge is necessary, which can be found in the IA Beginner's Guide.

Run pipeline in IA:

within the IA environment the pipeline can be executed
with two single commands:

derive SPD:
derive AAR:
spd = dspd( erd )
aar = daar( spd )
Derive SPD from ERD:

determine valid ranges:
subtract bitvalue 0 Volt:
correct for rest pulse:
linearize measurement:
correct for cross talk:
find and flag glitches:
determine slopes:
get grating angle:
get Fabry-Pérot gap:
calibrate wavelengths:

erd = drange( erd )
erd = midbit( erd )
erd = pulse_shape( erd )
erd = accor( erd )
erd = crosscor( erd )
erd = glitch( erd, gll )
spd = slope( erd, gll )
spd = get_grat_ang( spd )
spd = get_FP_gap( spd )
spd = wave( spd )

Derive AAR from SPD:

remove memory effects:

dark subtraction:

updown calibration:

responsivity calibration:

flux conversion:

velocity correction:

extract AAR:
spd = antimem( spd )
spd = dark( spd )
[ spd = updowncal( spd ) ]
spd = respcal( spd )
spd = fluxcon( spd )
spd = velcor( spd )
aar = extract_aar( spd, /all )

Documents:

SWS Instrument Data User's Manual

IA Online Documentation

IA User Manual, ISO 94-65, Issue 1.1, May 24, 1996

IA Reference Manual, ISO 94-66, Issue 0.2, Mar 08, 1995

IA Programmer Manual, ISO 94-48, Issue 1.4, May 24, 1996

ISAP Documentation

IDL User's Guide, Version 5.0, RSI, March 1997

IDL Reference Guide, Vol. 1+2, Version 5.0, RSI, March 1997

SWS TUTORIAL : CALIBRATION << PIPELINE > ERD to SPD > dspd ...

Last update: 30-Jul-1998 by D. Kunze ( mail to: isodata@mpe.mpg.de )