FITS Export with custom Metadata

does anybody has experience in exporting data as a FITS file with custom Metadata (FITS header) information? So far I was only able to generate FITS files with the standard Mathematica FITS header template. The documentation gives no hint on whether custom Metadata export is supported and how it might be done.

The following suggestions from comp.soft-sys.math.mathematica do not work:

header=Import[<some FITS file>, "Metadata"]; 
Export<"test.fits",data ,"Metadata"->header] 

or

Export["test.fits",{"Data"->data,"Metadata"->header}]

What is the proper way to export my own Metadata to a FITS file ?

Cheers,

Markus

Update: response fr开发者_运维问答om Wolfram Support: "Mathematica does not yet support Export of metadata for FITS file. The example are referring to importing of this data. We do plan to support this in the future..." "There are also plans to include binary tables into FITS import functionality."

I will try to come up with some workaround.

According to the documentation for v.7 and v.8, there is a couple of ways of accomplishing what you want, and you almost have the rule form correct:

Export["test.fits", {"Data" -> data, "Metadata" -> header}, "Rules"]

The other ways are

Export["test.fits", header, "Metadata"]
Export["test.fits", {data, header}, {{"Data", "Metadata"}}]

note the double brackets around the element labels in the second method.

Edit: After some testing, due to prodding from @belisarius, whenever I include the "Metadata" element, I get an error stating that it is not a valid export element. Also, you can't export a "RawData" element, either. So, I'd submit a bug for two reasons: the metadata isn't user settable which is vitally important for any serious application. At a minimum, the user should at least be able to augment the default Mathematica metadata. Second, the documentation is woefully inadequate in describing what is a "valid" export element vs. import element. Of course, I'd describe all of the documentation for v.6 and beyond as woefully inadequate, so this is par for the course.

Mathematica 9 now allows export of metadata (header) entries, which are additive to the standard required entries. In the Help browser, search "FITS" and there is an example that shows this (with Export followed by Import to verify).