# ConvolvedFluxPlugin errors are underestimated

XMLWordPrintable

#### Details

• Type: Story
• Status: To Do
• Resolution: Unresolved
• Fix Version/s: None
• Component/s:
• Labels:
None
• Story Points:
6
• Team:
Data Release Production

#### Description

Because multiple convolutions have taken place and variance has been lost as covariance, the errors produced by the ConvolvedFluxPlugin are significantly underestimated. Can we do something about this?

#### Activity

Hide

Paul Price, would the ScaleVarianceTask that gets run before detection on coadds have also solved this?

Show
Yusra AlSayyad added a comment - Paul Price , would the ScaleVarianceTask that gets run before detection on coadds have also solved this?
Hide
Paul Price added a comment -

It might make it better, but it relies on empty sky, and there's no guarantee that you have any around the source footprint. But the fundamental problem is that you're losing variance every time you convolve, and if you're not tracking covariance then you have no idea what the true errors are.

Show
Paul Price added a comment - It might make it better, but it relies on empty sky, and there's no guarantee that you have any around the source footprint. But the fundamental problem is that you're losing variance every time you convolve, and if you're not tracking covariance then you have no idea what the true errors are.
Hide

I handle this issue in estimate GAaP flux errors, which is a more rigorous variant of ConvolvedFlux. Because the convolution kernel is always Gaussian in ConvolvedFluxPlugin it is a trivial case of the correction I implement in GAaP plugin. I can adopt my solution here, once I get my GAaP uncertainties reviewed and merged.

Show
Arun Kannawadi added a comment - I handle this issue in estimate GAaP flux errors, which is a more rigorous variant of ConvolvedFlux. Because the convolution kernel is always Gaussian in ConvolvedFluxPlugin it is a trivial case of the correction I implement in GAaP plugin. I can adopt my solution here, once I get my GAaP uncertainties reviewed and merged.

#### People

Assignee:
Reporter:
Paul Price
Watchers: