<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 12 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal;
font-family:"Arial","sans-serif";
color:windowtext;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Arial","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1F497D">Hi again,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1F497D"> I've received several requests for the IDL routine that does the ICSI correction described in the paper I sent earlier. Here it is.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1F497D">The inputs are the arrays of intensity and wavelength of the original data. The outputs are an array of corrected intensity at the original spectral resolution, and arrays of
intensity and wavelength at a finer spectral resolution (based on spline interpolation). If you are doing some sort of fit (e.g., single or multiple Gaussian), you should apply the fit to the corrected intensities at the original resolution. If you are computing
blue-red asymmetries, for example, you may find it useful to use the fine resolution data. Please let me know if you have any questions.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1F497D">Cheers,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1F497D">Jim<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt">
<div>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Klimchuk, James A. (GSFC-6710)
<br>
<b>Sent:</b> Monday, June 29, 2015 8:55 AM<br>
<b>To:</b> (Loops@solar.physics.montana.edu)<br>
<b>Subject:</b> new spectroscopic analysis tool<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">Hi everyone,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif""> You might be interested in a new tool that Spiros, Durgesh, and I have developed for analyzing spectra. It can be downloaded from
<a href="http://lanl.arxiv.org/abs/1506.08102">http://lanl.arxiv.org/abs/1506.08102</a>. The abstract is below.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">Hope to see many of you at Loops VII,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">Jim<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt">The detailed shapes of spectral line profiles provide valuable information about the emitting plasma, especially when the plasma contains an unresolved mixture of velocities, temperatures, and densities. As
a result of finite spectral resolution, the intensity measured by a spectrometer is the average intensity across a wavelength bin of non-zero size. It is assigned to the wavelength position at the center of the bin. However, the actual intensity at that discrete
position will be different if the profile is curved, as it invariably is. Standard fitting routines (spline, Gaussian, etc.) do not account for this difference, and this can result in significant errors when making sensitive measurements. Detection of asymmetries
in solar coronal emission lines is one example. Removal of line 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.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">********************************************************************************<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">James A. Klimchuk<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">NASA Goddard Space Flight Center<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">Solar Physics Lab, Code 671<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">Bldg. 21, Rm. 158<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">Greenbelt, MD 20771<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">USA<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif""> <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">Phone: 1-301-286-9060<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">Fax: 1-301-286-7194<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">E-mail: <a href="mailto:James.A.Klimchuk@nasa.gov">James.A.Klimchuk@nasa.gov</a>
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">Homepage: <a href="http://science.gsfc.nasa.gov/sed/index.cfm?fuseAction=people.jumpBio&&iPhonebookId=15844">
http://science.gsfc.nasa.gov/sed/index.cfm?fuseAction=people.jumpBio&&iPhonebookId=15844</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">No endorsement by NASA is implied for any correspondence related to my official role in professional organizations.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif""> <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial","sans-serif"">********************************************************************************<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</div>
</body>
</html>