IdealCam is an IDL GUI application developed for processing the raw data generated by CanariCam, one of the first-light instruments of GTC. It provides astronomers with an efficient tool to access, reduce, and analyze multi-extension mid-IR FITS files. Although IdealCam is optimized for the imaging and polarimetry data of CanariCam, it can also work with other types of data produced by CanariCam, T-ReCS (at Gemini-South), and Michelle (at Gemini-North).

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In order to get rid of the strong and highly variable thermal background coming from both the earth atmosphere and the telescope itself (a good way to think about this is to imagine that you are observing a star with your own eyes during daytime), state-of-the-art mid-infrared cameras are almost always working in a special mode called “chop and nod” (Gemini website has a very nice and detailed explanation of it). Meanwhile, due to the strong background and finite well depth of the detector, the mid-infrared array need to be read out with very short frame time (typically around 10 ms). Consequently, a raw mid-infrared FITS files is in fact more like a short movie, rather than a simple image, in the sense that each FITS consists of a large number of chop and nod frames. To see the final product of the observation (i.e., the science image of your interested object), those frames need to be properly combined. The FITS structure might be complex, and different cameras use different formats to save the chop/nod frames in their raw FITS files.

In this context, IDEALCam is a very convenient tool that can be used to check those mid-IR “movies”, and to stack frames to form the final image. Compared to other existing IRAF or IDL packages/procedures, the use of IDEALCam requires little skill of IDL. No IRAF or IDL programming is needed. You do not have to be an expert in the mid-IR FITS structure either. Once the program is compiled and started, every work can be done interactively with a graphical user interface.

IDEALCam is not merely an easy-to-use FITS viewer, it also provides a variety of analyzing tools, such as aperture photometry, S/N measurement, etc.(see the next section for more about IDEALCam’s capabilities). As a polarimetry reduction tool, IDEALCam will be able to calculate the Stokes parameters and visualize the polarizations.

Current release of IDEALCam does not have the capabilities to reduce spectroscopic data. However, one can still use it to open, check and stack those mid-IR spectroscopic FITS files.

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Available in the current release:

1. -Graphical user interface
   

2. -Support the following instruments and data types:
   

       CanariCam - imaging, spectroscopy, polarimetry

       T-ReCS - imaging, spectroscopy

       Michelle - imaging, spectroscopy

1. -Stack frames (with bad frame removed)
   

2. -Quick access to every single chop or nod frame saved in FITS
   

3. -Display a collection of FITS header keywords that are most relevant to the image reduction and analyses
   

4. -Label one or more frames as bad frame(s) and display the updated stacked image instantly
   

5. -A zoom screen that can show a portion of the image in detail
   

6. -Save each frame into a single FITS with a proper header
   

7. -Display images with different color and scale (similar to DS9)
   

8. -Aperture photometry and profile fitting on either a stacked image or a single frame
   

9. -Sky background, noise level, and Signal-to-noise measurements
   

10. -Measure the centroid and FWHM of each single frame
    

11. -A built-in database of fluxes of Cohen standards for each CanariCam filter
    

12. -Frame registration
    

13. -Polarimetry (Stokes parameters, polarization image, vector map)
    

Will be available in the next release:

1. -Calculate the sensitivity when an image of Cohen star is given
   

2. -Bad pixel correction
   

Planned to be added in the future releases:

1. -Jitter correction
   

2. -Strehl ratio measurement
   

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You can download the newest version of IDEALCam from here

To use the built-in Cohen star database, download this dat file, and save it to somewhere included in the IDL paths

Alternatively, you can download the zipped version, which contains all files you need to run IdealCam.

DEALCam is free to use for everyone. However, please let me know if you want to make any modification on the original version, unless you restrict the modified version to you own use. Thank you!

If you want to be added to a mailing list for future messages regarding the update of MiFi-Viewer, please send me an email (no content is needed)

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IDEALCam makes use of a bunch of routines from two libraries, IDL Astronomy Library and the library developed by Frank Varosi

IDL Astronomy Library can be downloaded from here

Frank Varosi’s library is available here

Once you have downloaded and decompressed those two files, IDEALCam is ready to run! (Do not forget to add them into your IDL path, or simply put these two folders under the IDL folder)

To compile and start IDEALCam from the IDL command line, type in:

IDL> .compile idealcam

IDL> idealcam

Or use the “Compile” and “Run” buttons in the IDL Development Environment.

I apologize that I have not written a manual for IDEALCam yet. However, most tasks can be done in a rather straightforward way. If you have any questions regarding the use of IDEALCam, please feel free to send me an email.

When using IDEALCam, you can find some hints from the status bar at the bottom of the GUI

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IDEALCam is developed in IDL 8.0. It has been tested in both IDL 8.0 and 7.0. However, the compatibility with IDL versions earlier than 7.0 is not guaranteed.

The compatibility between IDEALCam and Windows OS has not been tested throughout yet.

Due to the conflict between routine names, the function of frame registration using FFT method is not working properly with the IDL Astronomy Library. Solution: remove the file correl_optimize.pro from the Astronomy Library (removal of this routine does NOT have any side effect, since another file in Varosi’s library with the same name is actually an updated version of this routine)

If you try to open a FITS file that is damaged or not finished properly, IDEALCam may halt (not crash). In this case, you can either restart the program, or type in the IDL command line:

IDL> retall

This will allow you to stop the running of module for opening the file, and hopefully the remaining part of the GUI is still running and you can then select another file to open.

If you find any other bugs or actions that may cause a crash, please send me a message by email. Thank you very much!

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1. -V 1.2 (Nov 8 2011)
   

    Aperture polarimery

1. -V 1.1 (Nov 1 2011)
   

    Polarimetry Reduction

1. -V 1.0 (July 20 2011)
   

    Add frame registration (using centroids of the frames)

1. -V 0.9 (July 16 2011)
   

    Add a built-in data base of Cohen standard stars and their fluxes

1. -V 0.8 (July 6 2011)
   

    Add the module to read Michelle FITS files

1. -V 0.7 (June 25 2011)
   

    First published version

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