ryanhausen
commented
10 months ago Hi @prappleizer,
You are correct, FitsMap doesn't combine pointings. It will produce a layer for every input fits file.
I think creating a large mosaic of multiple fits files can indeed be memory/compute intensive. I am not an expert in the area, but I think Montage (http://montage.ipac.caltech.edu/) is a tool that people use.
Thanks,
Ryan
In the base example of fitsmap, you have a single pointing --- you only have multiple fits files if you have multiple bands.
The implication seems to be that if you want to make a viewer for a large area survey, and you have multiple fits files (say, pointings in a mosaic on the sky), you need to first combine these files into ones single fits file before passing to fitsmap? If that is true though, what does one do if the number of fits files is high (e.g., 4000 or so)? In this case, when you go to open/save a single fits file, you will likely run out of ram. (In my use case, the 4000 fits files correspond to ~64GB of ram memory required to hold the full array in memory). The showcase examples look like they contain a very large area that must have been many individual pointings/fits files at some point.... did they really output their whole imaging area to a single fits file? Or am I missing some way to take a directory of fits files and then view all the tiles in a single viewer instance? I tried running fitsmap on my directory, but every fits file became its own layer, rather than being mosaic-ed in one viewer layer. If one does have to combine every fits file together first, does anyone have advice on how the examples provided did so without running out of memory? I'd imagine those single fits files would but up in the terabyte sizes...
Cheers for any advice!