brownrb1

Making Progress With ISIS-But?

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I've been trying to learn how to use the ISIS program to do data reduction on my spectra and have been making some progress. When I get to PROFILE  I get this profile (which is attached) of spectrum from my Alpy calibration lamp. I acquired the calibration spectrum using different exposures - 10s, 20s, 60s, and 120s. This profile is from 10s exposure, but they are all about the same. I use an Atik Infinity monochrome camera. The resolution of the profile is not what I expect.Untitled.png.2ced0c70dcb13ff46fd730e3b40e729c.png been

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Posted (edited)

Did you check you raw data ? Could you send a screen copy of the calibration lamp ?

Edited by OlivierG

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Hi Olivier,

Attached are 2 raw images-a 10 s expoure and a 60 s exposure. Both are from Shelyak calibration. 

Thanks Again

Dick

Calibration_60s_20200720_155701-1.png

Vega-1_Calibration_10s_20200724_031049-1.png

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You have to rotate your camera of 180 degrees, your spectrum have the blue part on the right and red on the left.

 

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Hi Dick,

 

I have looked at your spectrum profile and I noticed that the signal level seems very low. I therefore suspect that what is displayed might be the result of the substraction of two profiles. In the "General" tab of Isis (if I am not mistaken), there is a box which indicates whether you want Isis to remove the sky background or not. The default value (box unchecked) is that you do want to remove the background. When you do the calibration part of the process, you need to ensure that the background is not removed, because the background is essentially equal to the signal. Therefore, you need to make sure that the box is checked when you do a lamp calibration (and only in the case of calibrating your profiles with a lamp). 

 

Let me know if that is useful.

 

Regards,

 

Arnaud

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