wwtdatatool wtml transfer-astrometry

The transfer-astrometry subcommand takes astrometric data from one WTML file and transfers them into other WTML files.

The main purpose of this command is to enable a workflow for efficiently fine-tuning image astrometry using the WWT Windows client.

Many images imported to WWT come with decent, but not excellent, astrometric information. Sometimes the easiest way to improve the astrometry of an image is to do so manually, using the image editing mode of the WWT Windows client. This editing mode allows you to write out a WTML file with improved astrometry for a batch of images. If you’re preparing an image for upload into the cloud, however, you’re likely dealing with two sets of WTMLs: one set for local editing, and one set for publication on the cloud. The WWT editing mode can only rewrite the first set. This tool gives a mechanism for transferring improved astrometry from the former to the latter.


wwtdatatool wtml transfer-astrometry {INPUT-WTML} {UPDATE-WTMLS...}
  • The INPUT-WTML argument is the path to an input WTML file.

  • The UPDATE-WTMLS argument gives the paths of one or more WTML files that will be updated with astrometric information from the input.


In typical usage, you might have a group of images being prepared for cloud upload. Each lives in its own directory, with an index_rel.wtml file defining the image specifications, including approximate astrometry. To refine the astrometry manually, first you might merge the individual index files into a master file:

wwtdatatool wtml merge img*/index_rel.wtml before_rel.wtml

Then you would generate a version of the file using local disk paths, suitable for opening in the WWT Windows client:

wwtdatatool wtml rewrite-disk before_rel.wtml before_disk.wtml

Then you would open this file in the WWT Windows client, tune up the astrometry, and save the results as, say after_disk.wtml.

Finally you would use this command to transfer the improved astrometry back to the source files:

wwtdatatool wtml transfer-astrometry after_disk.wtml img*/index_rel.wtml

You’d now be ready to continue your workflow of finalizing the data for publication and upload.


This tool works by matching up imagesets and places in the input file and the output files. This matching is done by name, since folder structures and URLs might vary (as in the example above). Therefore, if there are multiple different images with the same name, you’ll get unpredictable results. The tool will report when it detects duplicated names in the input file.

See Also