[Loops] new spectroscopic analysis tool

[Charles C. Kankelborg]

Hi Jim,

This is a needed improvement. This kind of interpolation has been available for some time, but I have not see in applied to spectra (where it is probably most needed, for all the reasons you point out). Sakurai and Shin derived analytically, in closed form, a spline interpolation with rigorous photon conservation:

Takashi Sakurai and Junho Shin, 2001
"Interpolation of One- and Two-Dimensional Images with Pixelwise Photon Number Conservation "
http://pasj.oxfordjournals.org/content/53/2/361.full

With our usual detectors (rear-illuminated CCDs) there can be significant charge spreading in the field free region, so the pixels are well defined (in effect, they are fuzzy and overlapping). A proper flux-conserving interpolation scheme should take that into account. To my knowledge, that has not been done.

Best regards,
Charles


> On 2015 Jun 29, , at 6:59 AM, Klimchuk, James A. (GSFC-6710) <james.a.klimchuk at nasa.gov> wrote:
> 
> Hi everyone,
> 
>  
> 
>     You might be interested in a new tool that Spiros, Durgesh, and I have developed for analyzing spectra. It can be downloaded fromhttp://lanl.arxiv.org/abs/1506.08102.  The abstract is below.
> 
>  
> 
> Hope to see many of you at Loops VII,
> 
> Jim
> 
>  
> 
> The detailed shapes of spectral line profiles provide valuable information about the emitting plasma, especially when the plasma contains an unresolvedline blends is another. We have developed an iterative procedure called Intensity Conserving Spline Interpolation (ICSI) that corrects for this effect. As its name implies, it conserves the observed intensity within each wavelength bin, which ordinary fits do not. Given the rapid convergence, speed of computation, and ease of use, we suggest that ICSI be made a standard component of the processing pipeline for spectroscopic data.
> 
>  
> 
>  
> 
> ********************************************************************************
> 
> James A. Klimchuk
> 
> NASA Goddard Space Flight Center
> 
> Solar Physics Lab, Code 671
> 
> Bldg. 21, Rm. 158
> 
> Greenbelt, MD  20771
> 
> USA
> 
>  
> 
> Phone:  1-301-286-9060
> 
> Fax:      1-301-286-7194
> 
> E-mail:  James.A.Klimchuk at nasa.gov
> 
> Homepage:  http://science.gsfc.nasa.gov/sed/index.cfm?fuseAction=people.jumpBio&&iPhonebookId=15844
> 
>  
> 
> No endorsement by NASA is implied for any correspondence related to my official role in professional organizations.
> 
>  
> 
> ********************************************************************************
> 
>  
> 
> _______________________________________________
> Loops mailing list
> Loops at solar.physics.montana.edu
> https://mithra.physics.montana.edu/mailman/listinfo/loops

________________________________________________________________________
Charles Kankelborg AC7NY |
260C EPS Building        | 
Physics Department       |  "We can lick gravity, but sometimes the
Montana State University |  paperwork is overwhelming."
Bozeman, MT 59717        | 
Phone: 406-994-7853      |          --Wernher von Braun
FAX:   406-994-4452      |
http://solar.physics.montana.edu/kankel/