Archives of Photographic PLates for Astronomical USE

Extended WFPDB metadata

The Extended WFPDB metadata structure is one possible way to avoid the disadvantages of the WFPDB metadata structure while still being more or less compliant with it, in other words it's a further development of the latter.

The two preliminary differences are:

  • the allocated length of text in each line in the files notes and quality is not limited which allows virtually any length of input data
  • the exposure time is given in seconds

The first one gives freedom to use arbitrary keywords with a desired syntax to describe observational data. It becomes easier and more efficient to parse such metadata by software to write the data into either FITS headers or database fields.

For the PyPlate software (which can parse the extended WFPDB metadata structure and is used for the APPLAUSE database) the following keywords have been used in the extended WFPDB metadata structure so far:

In the file notes:

exposure time: exp1,...,expn;– duration of each exposure (only for mutiple-exposure plates!)
exposure start: start1,...,startn;– start time of each exposure (only for multiple-exposure plates!)
exposure end: end1,...,endn;– end time of each exposure (only for multiple-exposure plates!)
object: obj1,...,objn;– the name of observation object for each exposure (only for multiple-exposure plates with multiple observation objects!)
object type: type1,...,typen;– the object type for each exposure (only for multiple-exposure plates with multiple observation objects!)
filter: filter1,...,filtern;– the name of filter for each exposure (only for multiple-exposure plates with multiple filters!)
focus: value1,...,valuen;– focus value(s) for each exposure
emulsion: name;– full emulsion name if it's too long to be given in the maindata file
original plate number: n;– the original plate number, if it's different from the assigned by you database plate number
prism name: name;– the observer's designation of the prism used in observation
prism angle: deg:min;– the dispersion angle (in degrees and minutes) of the prism used in observation
grating: name;– the observer's designation of the grating used in observation
half grating: north|south;– specification of either north or south half grating used in observation
observer note: note1, ..., noten;– original observer's comments, explanations or remarks
comment: comment1, ..., commentn;– your own comments, explanations or remarks
bibcode: code;– the ADS bibcode of a publication related to the plate(s)/observation(s) (only if available!)

In the file quality:

temperature: temp1,...,tempn;– air temperature(s) during observation
sky conditions: cond1, ..., condn;– any natural observing conditions, like, clouds, fog, moonlight, etc. (not for artificial observing conditions, like, lamp-light)
calmness: n; sharpness: n; transparency: n;– air conditions often given with a numeric value(s) in observational logbooks

See also

WFPDB metadata structure