  Context. The Neel IRAM KIDs Array (NIKA) is a fully-integrated measurement
system based on kinetic inductance detectors (KIDs) currently being developed
for millimeter wave astronomy. In a first technical run, NIKA was successfully
tested in 2009 at the Institute for Millimetric Radio Astronomy (IRAM) 30-meter
telescope at Pico Veleta, Spain. This prototype consisted of a 27-42 pixel
camera imaging at 150 GHz. Subsequently, an improved system has been developed
and tested in October 2010 at the Pico Veleta telescope. The instrument
upgrades included dual-band optics allowing simultaneous imaging at 150 GHz and
220 GHz, faster sampling electronics enabling synchronous measurement of up to
112 pixels per measurement band, improved single-pixel sensitivity, and the
fabrication of a sky simulator to replicate conditions present at the
telescope. Results. The new dual-band NIKA was successfully tested in October
2010, performing in-line with sky simulator predictions. Initially the sources
targeted during the 2009 run were re-imaged, verifying the improved system
performance. An optical NEP was then calculated to be around 2 \dot 10-16
W/Hz1/2. This improvement in comparison with the 2009 run verifies that NIKA is
approaching the target sensitivity for photon-noise limited ground-based
detectors. Taking advantage of the larger arrays and increased sensitivity, a
number of scientifically-relevant faint and extended objects were then imaged
including the Galactic Center SgrB2(FIR1), the radio galaxy Cygnus A and the
NGC1068 Seyfert galaxy. These targets were all observed simultaneously in the
150 GHz and 220 GHz atmospheric windows.
