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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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Elevations #5

Closed freekroelofs closed 6 years ago

freekroelofs commented 6 years ago

The MS files sometimes show negative elevations for non-flagged data.

rdeane commented 6 years ago

I presume you are seeing this using CASA's msplot? It's a CASA bug. You could compare the elevations in AIPS, which should give the same values as MeqSilhouette. Please let us know if you confirm this.

freekroelofs commented 6 years ago

We have confirmed that it is indeed a problem in CASA's plotms by plotting the elevations with eht-imaging. Do you happen to know why this bug occurs?

On Wed, Mar 14, 2018 at 11:58 AM, Roger Deane notifications@github.com wrote:

I presume you are seeing this using CASA's msplot? It's a CASA bug. You could compare the elevations in AIPS, which should give the same values as MeqSilhouette. Please let us know if you confirm this.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/rdeane/MeqSilhouette/issues/5#issuecomment-372981823, or mute the thread https://github.com/notifications/unsubscribe-auth/ARwfE3V7_r185jud8wKCOaKt2IbRBfnjks5tePffgaJpZM4SqMj0 .

rdeane commented 6 years ago

I don't recall exactly, but something to do with CASA assuming it's a km-scale array and therefore being able to assume an array centre in its elevation calculations. Perhaps worth logging a CASA ticket given that they are now incorporating more VLBI capability.