# There is a bug in the prescan bbox for megacam.

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## Details

• Type: Story
• Status: Done
• Resolution: Done
• Fix Version/s: None
• Component/s:
• Labels:
• Story Points:
1
• Sprint:
Science Pipelines DM-W15-1
• Team:

## Description

The bounding box of the prescan region in the megacam camera should have zero y extent (I think). Instead it goes from y=-1 to y=2. This is either a bug in the generation of the ampInfoTables or in the way the bounding boxes are interpreted.

## Attachments

1. megacam.png
13 kB

## Activity

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Simon Krughoff added a comment -

Dominique, do you mind taking a look at this? It is very small.

PR on github:
https://github.com/LSST/obs_cfht/pull/1

Show
Simon Krughoff added a comment - Dominique, do you mind taking a look at this? It is very small. PR on github: https://github.com/LSST/obs_cfht/pull/1
Hide
Dominique Boutigny added a comment -

Hi Simon,

Here are my remarks / comments

displayCamera.py :
o This a very nice and useful utility
o Would be better to make it directly executable (#!/usr/bin/env python and chmod +x) rather than having to type python displayCamera.py ?
o There is a strange shift in the location of the top rights CCD (see picture attached), is it expected or is it a bug in the geometry description ?
o Code is clean

genCameraRepository.py:
o extra blank line at 226/227
o Ok otherwise

Show
Dominique Boutigny added a comment - Hi Simon, Here are my remarks / comments displayCamera.py : o This a very nice and useful utility o Would be better to make it directly executable (#!/usr/bin/env python and chmod +x) rather than having to type python displayCamera.py ? o There is a strange shift in the location of the top rights CCD (see picture attached), is it expected or is it a bug in the geometry description ? o Code is clean genCameraRepository.py: o extra blank line at 226/227 o Ok otherwise
Hide
Simon Krughoff added a comment -

You're absolutely right. I'll make it executable.
I didn't see an attached image, but I'm assuming an example is ccd16. ccd16 appears to be a little higher in the focal plane than ccd15. This is expected assuming that the policy file I use to construct the camera is right. Here is an excerpt from Full_Megacam_geom.paf:

  Ccd: {  name: "ccd15"  serial: 8341173  index: 6 2  ptype: "top"  offset: 57.091500 31.488750  nQuarter: 2  orientation: 0.000000 0.000000 0.000000  }  Ccd: {  name: "ccd16"  serial: 8351114  index: 7 2  ptype: "top"  offset: 85.644000 31.542750  nQuarter: 2  orientation: 0.000000 0.000000 0.000000  }

Note the offset values. The y value for ccd16 is about 0.06mm higher than ccd15. That's what I see using displayCamera.py. I don't know if this is right, or even how to check it. Let me know if you have a suggestion.

I cleaned up the blank line. Thanks for the quick review!

Show
Simon Krughoff added a comment - You're absolutely right. I'll make it executable. I didn't see an attached image, but I'm assuming an example is ccd16. ccd16 appears to be a little higher in the focal plane than ccd15. This is expected assuming that the policy file I use to construct the camera is right. Here is an excerpt from Full_Megacam_geom.paf: Ccd: { name: "ccd15" serial: 8341173 index: 6 2 ptype: "top" offset: 57.091500 31.488750 nQuarter: 2 orientation: 0.000000 0.000000 0.000000 } Ccd: { name: "ccd16" serial: 8351114 index: 7 2 ptype: "top" offset: 85.644000 31.542750 nQuarter: 2 orientation: 0.000000 0.000000 0.000000 } Note the offset values. The y value for ccd16 is about 0.06mm higher than ccd15. That's what I see using displayCamera.py. I don't know if this is right, or even how to check it. Let me know if you have a suggestion. I cleaned up the blank line. Thanks for the quick review!
Hide
Dominique Boutigny added a comment -

Hi Simon,

Yes, I will do it early tomorrow morning.

Dominique

Dominique Boutigny - CNRS / CC-IN2P3
Now at SLAC National Accelerator Laboratory

Mail : boutigny@in2p3.fr - boutigny@slac.stanford.edu
Office : +1 650-926-5759 - Cellular : +1 774-232-0912

Show
Dominique Boutigny added a comment - Hi Simon, Yes, I will do it early tomorrow morning. Dominique – Dominique Boutigny - CNRS / CC-IN2P3 Now at SLAC National Accelerator Laboratory Mail : boutigny@in2p3.fr - boutigny@slac.stanford.edu Office : +1 650-926-5759 - Cellular : +1 774-232-0912
Hide
Dominique Boutigny added a comment -

Hi Simon,

Here are my remarks / comments

displayCamera.py :
o This a very nice and useful utility
o Would be better to make it directly executable (#!/usr/bin/env
python and chmod +x) rather than having to type python displayCamera.py ?
o There is a strange shift in the location of the top rights CCD (see
picture attached), is it expected or is it a bug in the geometry
description ?
o Code is clean

genCameraRepository.py:
o extra blank line at 226/227
o Ok otherwise

Extra question : What are the consequences of the bug affecting the
bounding boxes ?

Dominique

Dominique Boutigny - CNRS / CC-IN2P3
Now at SLAC National Accelerator Laboratory

Kavli Building - Room 221
Mail : boutigny@in2p3.fr - boutigny@slac.stanford.edu
Office : +1 650-926-5759 - Cellular : +1 774-232-0912

Show
Dominique Boutigny added a comment - Hi Simon, Here are my remarks / comments displayCamera.py : o This a very nice and useful utility o Would be better to make it directly executable (#!/usr/bin/env python and chmod +x) rather than having to type python displayCamera.py ? o There is a strange shift in the location of the top rights CCD (see picture attached), is it expected or is it a bug in the geometry description ? o Code is clean genCameraRepository.py: o extra blank line at 226/227 o Ok otherwise Extra question : What are the consequences of the bug affecting the bounding boxes ? Dominique – Dominique Boutigny - CNRS / CC-IN2P3 Now at SLAC National Accelerator Laboratory Kavli Building - Room 221 Mail : boutigny@in2p3.fr - boutigny@slac.stanford.edu Office : +1 650-926-5759 - Cellular : +1 774-232-0912
Hide
Simon Krughoff added a comment -

Dominique,

I don't know if this is an old comment coming through or what. I'm pretty sure we finished this up a while ago. To answer your last question, I don't think there is any practical implication to the bounding box bug. It was only in the prescan bounding box. Since we don't use that for anything, by default, I don't think it should have been an issue.

Show
Simon Krughoff added a comment - Dominique, I don't know if this is an old comment coming through or what. I'm pretty sure we finished this up a while ago. To answer your last question, I don't think there is any practical implication to the bounding box bug. It was only in the prescan bounding box. Since we don't use that for anything, by default, I don't think it should have been an issue.
Hide
Dominique Boutigny added a comment -

Hi Simon,

Yes, this is an old comment, but I am interested by the answer as I was
wondering if the consequences were important or not.

By the way, in case you ask yourself what happen with DM-1380 that you
reviewed, I want to fix DM-1057 before merging to the master branch in
order to get rid of some duplicate code.

Best regards,

Dominique

Dominique Boutigny - CNRS / CC-IN2P3
Now at SLAC National Accelerator Laboratory

Kavli Building - Room 221
Mail : boutigny@in2p3.fr - boutigny@slac.stanford.edu
Office : +1 650-926-5759 - Cellular : +1 774-232-0912

Show
Dominique Boutigny added a comment - Hi Simon, Yes, this is an old comment, but I am interested by the answer as I was wondering if the consequences were important or not. By the way, in case you ask yourself what happen with DM-1380 that you reviewed, I want to fix DM-1057 before merging to the master branch in order to get rid of some duplicate code. Best regards, Dominique – Dominique Boutigny - CNRS / CC-IN2P3 Now at SLAC National Accelerator Laboratory Kavli Building - Room 221 Mail : boutigny@in2p3.fr - boutigny@slac.stanford.edu Office : +1 650-926-5759 - Cellular : +1 774-232-0912

## People

• Assignee:
Simon Krughoff
Reporter:
Simon Krughoff
Reviewers:
Dominique Boutigny
Watchers:
Dominique Boutigny, Simon Krughoff