Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

RASCIL simulation leads to black dirty images #626

Open
1 of 6 tasks
mpluess opened this issue Oct 9, 2024 · 3 comments
Open
1 of 6 tasks

RASCIL simulation leads to black dirty images #626

mpluess opened this issue Oct 9, 2024 · 3 comments
Assignees
@anawas
Labels
bug Something isn't working prio-high High priority

Comments

@mpluess
Copy link
Member

mpluess commented Oct 9, 2024 •
edited by anawas
Loading

Tested with karabo.simulation.sample_simulation.run_sample_simulation as well as karabo.test.test_simulation.test_backend_simulations.
On the example of test_backend_simulations, I verified that the problem is not the recently introduced export_visibility_to_ms call for the output. It's the same if one uses the generated visibilities before writing them to disk.
I also verified that us not having the RASCIL data dir (see https://developer.skao.int/projects/rascil/en/latest/RASCIL_install.html#installation-via-pip) is not the problem.

  • Lukas mentioned there might be a different RASCIL data dir, apart from the one mentioned @ https://developer.skao.int/projects/rascil/en/latest/RASCIL_install.html#installation-via-pip, which we might be missing, which in turn might lead to simulations not working. Probably a direction that should be investigated.
  • Check if the RASCIL output in karabo.simulation.line_emission.py is still okay (Luis investigated differences between OSKAR and RASCIL on this example, so RASCIL should've been running fine when he merged this, at least on his machine)
  • Investigate and fix
  • Verify dirty image turns out the same, regardless of using generated visibilities before writing them to disk or using the disk export after export_visibility_to_ms
  • Remove NotImplementedError for RASCIL backend @ karabo.simulation.sample_simulation.run_sample_simulation
  • Include RASCIL simulations again @ karabo.test.test_sim_format_imager_combos
@mpluess mpluess added bug Something isn't working prio-high High priority labels Oct 9, 2024
@sfiruch sfiruch changed the title Dirty images from RASCIL simulation outputs only produce zeros RASCIL simulation leads to black dirty images Oct 10, 2024
@sfiruch
Copy link
Member

sfiruch commented Oct 10, 2024

We should check if "Re" and "Im" parts of visibilities are zeros.

@anawas anawas self-assigned this Feb 12, 2025
@anawas
Copy link
Collaborator

anawas commented Feb 20, 2025

Some updates regarding this issue:

There are certain combinations of backend, imager and sky models that lead to black (a.k.a empty) dirty images. To be brief:

backend dirty imager sky model black image
RASCIL RASCIL GLEAM, MIGHTEE, MALS, virtual sky yes
RASCIL RASCIL HI sources catalog no
RASCIL OSKAR GLEAM, MIGHTEE, MALS, virtual sky yes
RASCIL OSKAR HI sources catalog no
OSKAR RASCIL all catalogs no
OSKAR OSKAR all catalogs no

I used the following test setup:

  • Telescope was "MID" for RASCIL and "SKA1MID" for OSKAR
  • I made sure all the sources were above the horizon
  • The frequencies were set to match the ones in the survey

For the black images I checked the real and imaginary parts of the visibilities as @sfiruch suggested. They are all zero indeed. After some extensive debugging, I found that the function convert_to_backend(...) -> Union[SkyModel, List[SkyComponent]] of karabo.simulation.sky_model.SkyModel only returns a nonempty new SkyModel if it was initialized with a HI source catalog. In all other cases, the new model had no sources.

Since this function is only called when the visibilities are calculated with RASCIL, I reckon that the bug is within this function. I will investigate this further.

@mpluess
Copy link
Member Author

mpluess commented Feb 20, 2025

Nice work!

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees

@anawas anawas

Labels
bug Something isn't working prio-high High priority
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
3 participants
@sfiruch @anawas @mpluess
pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.


Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy