The current transition from the VLA correlator to the new EVLA WIDAR correlator introduces changes in the way observations are being prepared. Previously, observations using the VLA correlator were prepared with the JObserve software, but the new expanded range receiver tuning and configuring of the very flexible WIDAR correlator has required the development of a new web-based application: the Observation Preparation Tool (OPT).
A preliminary version of the OPT has been in use since March 2009. This preliminary version was used mainly to prepare observing schedules, or scheduling blocks, for observing using the new Ka-band (26.5 - 40 GHz) receivers. Special temporary code was introduced to configure the (old) VLA correlator.
With the shutdown of the VLA correlator JObserve will no longer be used to prepare observations for the EVLA. All new observations must now be prepared using the OPT. Release version 1.0 of the OPT is now available, which accommodates all correlator configurations supported under the Open Shared Risk Observing program.
The OPT can be accessed through the NRAO user portal by selecting the "Obs. Prep." tab in the Dashboard.