The ATCA Forum

Thanks Mark! I'll let you know if I find anything unexpected.

Cheers,
Andrew

Hi Mark, Jamie: I'm trying to taper the visibilities in my 1.1-3.1 GHz data to achieve the same beam size across 471 pointings. However, invert only contains a "fwhm" parameter, and not a "pa" parameter (like restor and convol do). I've tried using the fwhm parameter without bein...

Hi Mark,

Thanks for that. I am using convol with options=final. We'll see how I go with tapering...

Cheers,
Andrew

Hi Mark, Jamie, I'm wondering if you can tell me how linmos calculates effective frequency when you set options=frequency. If it helps, I'm making a large 25 deg^2 mosaic at 1-3 GHz (as you might know from my other ATCA forum posts). And how do I interpret the flux densities in my image mosaic given...

Hi Mark, There isn't much of a difference between the processing of the sub-bands vs. the full 2.0 GHz bandwidth. These are the only differences: in the full-band, the selfcal interval is 5, the Gaussian beam I convolve to is fwhm=5.39,4.21 pa=2.4, and of course the bw parameter in linmos is 2.0. Ot...

Hi Mark, Thanks for the Miriad update. I've been able to simultaneously feed linmos all 3297 images (which all have the same size) from all 7 sub-bands and successfully make a mosaic (each pointing was stacked using the images from the 7 sub-bands). However, when I plot the ratio of the integrated f...

Hi all, I'm trying to understand the two different ways in which linmos performs the primary beam correction. Under the "bw" keyword in the linmos help file, it says: "Bandwidth of the image in GHz, default 0. If specified the beam response will either be averaged across the frequency...

Hi Mark, I've realised that linmos actually produces 10 primary beam objects per image (corresponding to 10 frequency intervals across the bandwidth). So, since I feed it 3297 images, the number of primary beam objects it tries to process is 32970, exceeding its maximum. Would it be possible to incr...

Hi Mark, That's interesting that the maximum number of primary beam objects linmos can handle is 20000, and yet it can't handle the 3297 objects I give it. The limit on the image size is harder to avoid - you might need to make overlapping images of 32768*32768 pixels. Are you implying here that lin...

Hi all, I am trying to mosaic together a large number of pointings using linmos. I've imaged my field in 7 sub-bands (at central frequencies between 1460-2996 MHz), with each sub-band having 471 individual pointings (for a total of 3297 images). Each image's file size is about 200 MB. Linmos clearly...