Description of the FITS structure file used to store of processing of instrumental data ("proc" format). Proc-files are the essential core of data formats in Munipack. Processing actions keeps their results in the extensions of this kind of file. All other actions uses proc-file as input.
Proc-file is not created by only one action, but the extensions are created by various ones. Objects detection and aperture photometry is provided by munipack find, munipack aphot modules. The astrometry calibration is determined by munipack astrometry. The photometry calibration is determined by munipack phcal.
Proc-file specification has been developed for internal use in Munipack and follows rules introduced by original DAOPHOT. Any backward compatibility is not guarantied.
The primary data array is followed by FIND, APERPHOT and GROWCURVE extensions. The order of the extensions can vary (use the name rather then index to access required extension).
| HDU | EXTNAME | Description | Action |
|---|---|---|---|
| 0 | Primary array (frame) | ||
| 1 | FIND | Table of detected objects | find |
| 2 | APERPHOT | Aperture Photometry table | aphot |
| 3 | GROWCURVE | Growth curve table | aphot |
Data in primary array is untouched during objects detection (find) and aperture photometry phase. GAIN, READNS and SATURATE keywords may by modified on user request.
The table contains detected objects.
| Keyword | Description | Units |
|---|---|---|
| EXTNAME | FIND as the identifier of this table | |
| FWHM | typical full width at half of maximum for a detected object | pixels |
| THRESH | threshold for detection of peak of stars in sigmas of sky above sky mean level in a region | |
| LOBAD | Lower good datum | ADU |
| HIBAD | Higher good datum | ADU |
| RNDLO | Round low | |
| RNDHI | Round high | |
| SHRPLO | Sharp low | |
| SHRPHI | Sharp high |
Header contains additional information in more human-readable format.
Star detection parameters: Gain (e-/ADU)= [..] (see primary HDU) Saturation (ADU)= [..] (see primary HDU) Read noise (ADU)= [..] (see primary HDU) Lower threshold (sigma)= [..] Levels range (ADU) = [..] .. [..] Round range = -1.00000000 .. 1.00000000 Sharp range = 0.200000003 .. 1.00000000 Approximate sky value = [sky] +- [skysig] Pixels used for sky determination = 10000
| Column | Description | unit |
|---|---|---|
| X | Horizontal coordinate | pix |
| Y | Vertical coordinate | pix |
| SHARP | sharp parameter | |
| ROUND | round parameter | |
| PEAKRATIO | Ratio of peak to background (sky level) |
The table is sorted by PEAKRATIO column in decrease order (with bright stars on top).
This extension contains aperture photometry of all object in a given set of apertures. Also a sky level measured in a ring shaped neighbourhood of every star is estimated.
| Keyword | Units | Description |
|---|---|---|
| EXTNAME | APERPHOT as the identifier of this table | |
| HWHM | HWHM estimated by momentum method | |
| NAPER | Count of apertures | |
| APERi | pix | Radius of i-th aperture, i = 1..NAPER |
| ANNULUS1 | pix | inner sky annulus radius in pixels |
| ANNULUS2 | pix | outer sky annulus radius in pixels |
The aperture photometry table.
| Column | Description | unit |
|---|---|---|
| X | Horizontal coordinate[§] | pix |
| Y | Vertical coordinate[§] | pix |
| SKY | counts | Sky level |
| SKYERR | counts | Sky level error |
| APCOUNTi | counts | Sum of counts in i-th aperture[*] |
| APCOUNTERRi | counts | Statistical error of APCOUNTi |
[§] This column is a direct copy of one from FIND extension.
[*] Negative values means impossibility to determine the value. Common reasons are: the high sky background level (for faint stars) or a large aperture radius exceeding frame boundary (for stars near an edge) or saturation (for very bright stars).
This extension contains results of growth-curve photometry for all stars in APERPHOT table.
| Keyword | Units | Description |
|---|---|---|
| EXTNAME | GROWCURVE as the identifier of this table | |
| HWHM | pix | HWHM estimated by growth curve in pixels |
| RADFLX90 | pix | Radius containing 90% of energy |
| Column | Description | unit |
|---|---|---|
| X | Horizontal coordinate | pix |
| Y | Vertical coordinate | pix |
| SKY | Sky level[^] | count |
| SKYERR | Statistical error of sky level | count |
| GCOUNT | Growth curve estimated total sum of counts for an infinite aperture[*] | count |
| GCOUNTERR | Statistical error of APCOUNT | count |
| GROWFLAG | Classification: used (0), not used (1) for construction of growth-curve, non-stellar object (2). |
[^] Values of sky will generall differ from those from the aperture photometry table APERPHOT. Growth-curve photometry gives corrections to the sky.
This extension saves growth curve and derived radial profile in selected apertures.
| Column | Description | unit |
|---|---|---|
| R | Radius of the aperture | pix |
| GROWCURVE | growth curve value at R | |
| GROWCURVEERR | Statistical error of growth curve | |
| RADIALPROFILE | Radial profile at R |
Detection of Stars, Aperture Photometry, Growth Curve Overview.