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rdeane / MeqSilhouette

A synthetic data simulation package for the Event Horizon Telescope
GNU General Public License v2.0
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Station-dependent pointing error sampling interval #13

Open iniyannatarajan opened 5 years ago

iniyannatarajan commented 5 years ago

Suggestion from @mjanssen2308 : I think this seeing timescale should basically be equal to the c_time, so no new input parameters would be needed.

mjanssen2308 commented 5 years ago

This is related to https://github.com/rdeane/MeqSilhouette/issues/14. I thought there could be an additional type of pointing offsets on short timescales, related to atmospheric seeing and wind. These could happen on c_time timescales, which are different per telescope. And the magnitude of the effect could either be set in another column in the station input file, from something like ptg_rms_short[arcsec]. Or a single parameter x could be set and x*ptg_rms will be used for simplicity. Maybe we should meet via skype at some point to discuss this and then you and Roger can decide if this would be a useful feature to have.

rdeane commented 5 years ago

Yes, this makes sense and will provide a physical motivation for some of the intra-scan amplitude gain variability. Do you know if we have physical constraints on these variations, apart from what we see from self-cal solutions?

Iniyan is in Cambridge (UK) this week and I'm travelling around SA for a few things, so the following week would probably be better for both us.

On Thu, 9 May 2019 at 13:30, mjanssen2308 notifications@github.com wrote:

This is related to #14 https://github.com/rdeane/MeqSilhouette/issues/14 . I thought there could be an additional type of pointing offsets on short timescales, related to atmospheric seeing and wind. These could happen on c_time timescales, which are different per telescope. And the magnitude of the effect could either be set in another column in the station input file, from something like ptg_rms_short[arcsec]. Or a single parameter x could be set and x*ptg_rms will be used for simplicity. Maybe we should meet via skype at some point to discuss this and then you and Roger can decide if this would be a useful feature to have.

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mjanssen2308 commented 5 years ago

Remo will try to dig up some numbers for the atmospheric seeing from logs of connected element interferometers. I think it will depend very much on the weather conditions.

Will stay in touch.