By using the "pixel shift" feature of our software, we stepped through the H-alpha line from slightly blue (top left) to slightly red (bottom right). The mosaic below is from -7 to +7 pixels. Data is from a single SER file taken at 06:56 UTC on July 16. Click on the image to see at a larger scale.
The centre (minimum brightness) of the H-alpha line corresponds to the central image. Each shifted image corresponds to a wavelength displacement of 7.9 picometers. The theoretical spectral resolution is about 20 picometers (0.2 angstroms). The range of wavelength shift from blue to red is a total of only 1.1 angstrom. This shows how important the proper tuning of an etalon filter is.
If you look carefully, you can see the Doppler shift due to the solar rotation. Assuming the rotational speed at the equator is v = 2 km/s, the Doppler shift from the east to the west limb is 2 x v/c x 656.3nm = 8.75 picometers.
Off-band H-alpha images
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Re: Off-band H-alpha images
I really love it how you can extract so much data from just one video file
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Re: Off-band H-alpha images
Brilliant comparison Douglas.
I'm going to make a copy of this for the reference library as a lot of etalon users will find this useful to I think.
I'm going to make a copy of this for the reference library as a lot of etalon users will find this useful to I think.
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!