1D profile - a problem!

[Gasman]

Hi guys

Must admit to having a slight problem with the term '1D profile. To me this implies a movement on only one axis on a graph either x or y when actually a spectrum is plotted in both x (wavelength)  and y (intensity) directions so surely it should be referred to as a '2D profile' ?.

Regards

Steve

[robin_astro]

Hi Steve,

By your definition an image would be 3D as each X,Y location has an intensity  (It is actually a 2D matrix of intensity values)

fits file spectrum profiles usually are strict 1D arrays  (a single list of intensities, the relationship between wavelength and index being defined separately)  but in general it is a useful way to distinguish between a 2D raw spectrum image and a 1D spectrum image generated from the profile in which the rows are repeated.

Cheers

Robin

[Gasman]

Point taken Robin ? I suppose it's when you say "the relationship between wavelength and index being defined separately" the confusion arises ( or my confusion at least ?)

cheers

Steve

[Merlin66]

To keep it simple. The 1D fits used to define the spectral profile is basically a list of intensities (Y height) for a series of X positions. 

Converting the X positions to a wavelength scale is provided by the calibration formula also included. 

[Jack Martin]

Steve,

I could post an example if it helps, but not sure if this forum accepts fits images ?

Regards,

Jack

Huggins Spectroscopic Observatory

 

[Gasman]

Hi Jack

Sorry just noticed your reply. A screen grab of the fits and saved as a .png or .jpg file would be fine on the forum if poss?.

Cheers

Steve

[Jack Martin]

Steve,

Just seen your reply I will post as requested.

I am using BASS to data reduce my spectra which works well.

Regards,

Jack

Huggins Spectroscopic Observatory

[Jack Martin]

Steve,

Would it be easier to send files to your e mail address ?

Regards,

Jack

Huggins Spectroscopic Observatory