Purpose of Document

This document summarizes the instrumental status of the Expanded Very Large Array (EVLA) until the start of D-configuration on January 25, 2013.  For observations after that date, we refer to the appropriate OSS version.

The OSS intended as a ready reference for those contemplating use of the EVLA for their astronomical research. The information is in summary form - those requiring greater detail should consult the EVLA's staff members, listed in Key Personnel, or refer to the manuals and documentation listed in Documentation. Most of the information contained here, and much more, is available through the EVLA science web pages, and the companion document for the VLBA.

The EVLA is a large and complex modern instrument. Some familiarity with the principles and practices of its operation is necessary for efficient use to be made of it. Although the NRAO strives to make using the EVLA as simple as possible, users must be aware that proper selection of observing mode and calibration technique is often crucial to the success of an observing program. Inexperienced and first-time users are especially encouraged to enlist the assistance of an experienced colleague or NRAO staff member for advice on, or direct participation in, an observing program. Refer to Help for Visitors to the EVLA and DSOC for details. The EVLA will be an extremely flexible instrument, and we are always interested in imaginative and innovative ways of using it.