The ngVLA will use multiple array components to cover angular scales ranging from many arcminutes down to fractions of a milli-arcsecond. As currently envisioned, it consists of 3 primary components:

• The main interferometric array (Main) will have 214 18-meter diameter antennas with baselines between ~40 meters and 1,273 km. It includes antennas throughout New Mexico, west Texas, eastern Arizona, and northern Mexico.

• The long baseline array (Long) will have 30 18-meter antennas distributed among 10 sites, with baselines between ~500 km and 8,636 km. It includes stations in Hawaii, Washington, Wyoming, California, Iowa, West Virginia, Florida, New Hampshire, and Puerto Rico.

• The short baseline array (SBA) will have 19 6-meter diameter antennas and baselines between 11 meters and 60 meters. It will be located near center of the current VLA.

To measure larger spatial scales, a subset of the 18-meter antennas will be capable of performing single dish measurements.

The Main interferometric array of 18-m antennas is further divided into the following sub-components:

• Core, which has 114 antennas in a semi-random, centrally condensed distribution ~4.5km in diameter on the Plains of San Agustin. It is optimized for high surface-brightness sensitivity.

• Spiral, which has 54 antennas in a 5-arm spiral extending outward from the core to baselines up to approximately 40km, comparable to the longest baselines of the VLA.

• Mid, which has 46 antennas spread over the state of New Mexico and into adjacent states, providing baselines up to ~1270km.

In order to optimize the baseline distribution for different science projects, it is envisioned that these array elements will be flexibly combined into subarrays that can observe in parallel, with up to 10 subarrays observing at a time. The ngECT provides sensitivity estimates for a variety of ngVLA subarrays and science cases. For information about simulating observations with the ngVLA, refer to the ngVLA tools page.

The ngVLA configuration design has evolved over time based on input from the scientific community, practical siting issues--- e.g., considerations of roads, fiber, and power--- as well as technical investigations. More detailed information is available in ngVLA memos 3, 12, 16, 41, 43, 47, 92, 100, 102, 104, 105, 111, 122, 124, and 129. The currently planned array configuration is Revision F (Rev.F).

The ngVLA will have approximately ten times the sensitivity of the VLA and ALMA between 1 and 115 GHz; continental-scale baselines providing sub-milliarcsecond-resolution; and a dense core on km-scales for high surface brightness sensitivity. As such, it will be the world's premier cm- and long-mm wave telescope, bridging the gap between ALMA--- a superb sub-mm array--- and the future SKA1, which is optimized for longer wavelengths.