ISIS merged order wavelength shift error

Post Reply
Bernard Heathcote
Posts: 84
Joined: Mon Sep 26, 2011 10:09 am

ISIS merged order wavelength shift error

Post by Bernard Heathcote »

Some time back I discovered that when ISIS generates a merged profile from eShel orders that there is a significant wavelength error.
I did report this at the time, in May, (see http://www.spectro-aras.com/forum/viewt ... f=8&t=2959) but there were no useful responses. As I consider this a significant problem I am now trying again.

I am using the latest 6.1.1 version of ISIS. I don't know if earlier versions had the same problem but if they did then I certainly never noticed it.

There is no wavelength shift with the individual orders, so the error is only introduced during the merge process.

The plots below show the correct wavelength for individual orders and the shift for the merged orders.

Has anyone else had this problem?

Cheers,
Bernard H.
Attachments
Individual orders
Individual orders
Merged orders wavelength shift
Merged orders wavelength shift
Post Reply