  LWA1 is a new large radio telescope array operating in the frequency range
10-88 MHz, located in central New Mexico. The telescope consists of 260 pairs
of dipole-type antennas whose outputs are individually digitized and formed
into beams. Simultaneously, signals from all dipoles can be recorded using one
of the telescope's "all dipoles" modes, facilitating all-sky imaging. Notable
features of the instrument include four independently-steerable beams utilizing
digital "true time delay" beamforming, high intrinsic sensitivity (about 6 kJy
zenith system equivalent flux density), large instantaneous bandwidth (up to 78
MHz), and large field of view (about 3-10 degrees, depending on frequency and
zenith angle of pointing). This paper summarizes the design of LWA1, its
performance as determined in commissioning experiments, and results from early
science observations demonstrating the capabilities of the instrument.
