AperturePhotometry question

[CraigNZ]

How does the AperturePhotometry script use DynamicPSF?  Does it use the last settings configured by the user or does it default to a predefined set?  If so, what are the DynamicPSF parameters used?  I didn't see any way of setting up these parameters in the AperturePhotometry script.

[Juan Conejero]

AperturePhotometry always fits an elliptic Gaussian PSF model. See lines 2281 and 2306-2321 of AperturePhotometry.js:

Code: [Select]

      var DPSF = new DynamicPSF;
      ...
      DPSF.stars = stars;
      DPSF.psf = psf;
      DPSF.searchRadius = 8;
      DPSF.autoPSF = false;
      DPSF.gaussianPSF = true;
      DPSF.circularPSF = false;
      DPSF.moffatPSF = false;
      DPSF.moffat10PSF = false;
      DPSF.moffat8PSF = false;
      DPSF.moffat6PSF = false;
      DPSF.moffat4PSF = false;
      DPSF.moffat25PSF = false;
      DPSF.moffat15PSF = false;
      DPSF.lorentzianPSF = false;
      //console.writeln(DPSF.toSource());
      var res = DPSF.executeGlobal();


[cwiede]

Hi,
I suppose this does not mean, that the aperture used to do photometry on a file does depend on the measured FWHM. If you have long time series with changing seeing or focus the script nevertheless uses the same aperture size for all the frames, right? Would it be a good idea to change that?
Best regards
Christof

[CraigNZ]

Would it be very difficult to use the configuration settings from DynamicPSF?  That way we could setup our preference, and be able to change it based on a specific image or series of images.

[Andres.Pozo]

In this script DynamicPSF is only used for finding the centroid of the stars. The configuration of DPSF has very little effect in the centroid calculation. I could add the capability of configuring DPSF but it would be a lot of effort for gaining nothing.

In any case the script has a BSD licence and it is hosted in a public repository in GitHub so ....