Observing > NRAO Archive Tool Enhancements

NRAO Archive Tool Enhancements

On May 2, 2022, the NRAO transitioned to the new Archive Access Tool (AAT) for the VLA, VLBA, Legacy VLA, and GBT data. This new tool also includes ALMA data in its search returns. While the capabilities of this new archive tool go above and beyond what was possible with the legacy archive tool, we recognize that the transition for our users has not been entirely smooth. The NRAO is committed to maintaining and expanding the new archive interface and its capabilities to improve the experience of our users.

We value feedback from our user community on improving the NRAO archive tool. If a user has a feature request, or feedback on how a current feature/implementation could work better, they can file a helpdesk ticket at help.nrao.edu via the department: ‘Archive Access Tool Feedback.’

In the most recent release of the AAT (v 4.1.1, June 2022), the NRAO addressed some highly desired features:

  • Data delivery for non-staff users in New Mexico (i.e., nm- visitor account holders) to their lustre disk areas.
  • Improved data delivery speed.
  • Organization of individual VLBA observations into their observation segments.

For the upcoming releases, the NRAO has prioritized the following areas for development:

  • Scriptability of the archive query interface via VO-compliant Table Access Protocol (TAP).
  • Download improvements (inclusion of wget commands to retrieve data).
  • Search improvements.
  • Position search fixes (see Known Issues below).
  • Search based on integration time.
  • Scanlist improvements


  • Metadata display improvements (i.e., scan list, sources, frequency setup(s), total integration times).


  • Completion of VLBA data collection: Fixing corrupted Mark IV files, and adding a few missing GMVA, HSA, and Global VLBI data.
  • Downloading large numbers (>500) of correlation files for VLBA projects in bulk via the 'Select All' option.
  • Fixing the missing or incomplete metadata of some VLBA+EVLA (i.e. +Y1, +Y27) projects, without which download is impossible. For the time being, please contact our helpdesk to gain access if you are PI or CoI of the affected projects.


Known Issues affecting data in the archive and archive use (which we are working on to address):

  • All data deliveries come in a nested directory structure where your file, MS, or SDM is within directories that have the same name as your file, MS, or SDM. The actual files or MS/SDMs of interest are two or three levels inside this directory structure.
  • Position based searches return sources outside requested radius
  • The current position search will return results that are overly permissive and may not be as restrictive as desired. Frequency-dependent field of view searches are not properly implemented.
  • Insufficient metadata are displayed for VLA data with regard to their frequency setup, sources, and times on source.