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batch of spectra to upload

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batch of spectra to upload

Dear AVSpec maintainer,

Can you please point out how can I upload massive number (a or batch) of spectra, ideally in such a way that others can download with a single click, and doesn't disturb others in browseability (won't look like a flood) ?

e.g. I have a nightly serie (5 hour) of a star, collected 49 spectra (with various exposure times, of course).

Grouping sum of exposures is not always desirable (sometimes I do it for demo purpose, but several other groupings possible), and there are other projects (e.g. pulsating stars, ...) that require a serie of spectra to upload one by one (their sum is pointless to use).

Not to mention, any math on spectra in 1D like sum usually destroy/cheat certain fields, e.g. DATE-OBS, EXPOSURE,... with many others - lots of manual effort required to take care of them, with human error possibilities.

Or shall I just freely upload them as-is, all the #49 ?

Thank you in advance,




Hey Peter,

There is a way to select multiple files to upload all at once. They will likely need to be in the same folder. It is a bit difficult to explain so I will send you a follow up email separately. However, There is currently no way to download them all in batch. Each file will need to be downloaded separately. If this is something that the community feels would be useful we can look into the work needed to add a feature like this, but this will not be available for the forseeable future. 

Bert Pablo
Staff Astronomer, AAVSO


Hello Bert,

Thank you for the quick answer, I'm going to start using it extensively then (hope others won't complain), for the project stars advertised here at least.


Robin Leadbeater
headers for multiple exposures

Hi Peter,

Combined multiple exposures are handled correctly in the header in ISIS  (though not with varying exposure times of course) eg

VERSION       'ISIS V5.9.3'        / Software version

OBJNAME      'C2020 F3 NEOWISE'   / Current name of the object

DATE-OBS     '2020-07-10T23:48:10' / Date of observation start

EXPTIME        245 / [s] Total time of exposure

EXPTIME2      '8 x 30 s'           / Exposure decomposition

JD-OBS           2459041.4918 / JD start observation

JD-MID           2459041.4932 / JD mid observation

The BAA spectroscopic database handles batch uploads (up to 30) and downloads (up to 250, based on selection criteria)



headers for multiple exposures

Hello Robin,

This is true as long as you are grouping exposures in 2D, which is not possible in ISIS when you have [automated] calibrations between each exposures (and definitely want to use them correctly), e.g. LHires III that moves for me many pixels during night, mostly when temperature changes (can happen in a short time unexpectedly). So I process them 1 by 1, using 2 neighbour calibrations averaged. (The existing 'wavelength registration' feature sometimes useable, sometimes not - for good reasons.)
With my ISIS version (v5.7.0), working on series of spectra (ISIS -> Spectra processing tab 2 -> sum) - after renaming manually e.g. group1-1 group1-2 ...- causes absolutely wrong fits headers (DATE-OBS, JD-OBS, JD-MID, EXPOSURE all wrong). Maybe requires development (if there are more users for this feature...).

Yes, I also do varying exposure time for bright stars (or the opposite: simply after realize how faint it is), to max out SNR (my readout noise is a big factor). Till object is low, I usually more exp. times, adjusting it later on the fly. Maybe it's also a reason why grouped sum in 1D is neglected by software.



BASS Project processing

BASS Project processing software produces the same FITS header information as shown by Robin for ISIS.

( I can get the same data from my acquisition software Astroart)


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