“First Light” with the BYU/NRAO Prototype 19 Element Focal Plane Array on the Green Bank 20 Meter Reflector Jonathan Landon, Jacob Waldron, David Jones, Allan Stemmons, Mike Elmer, Brian Jeffs, Karl Warnick – BYU Rick Fisher, Rich Bradley, and Roger Norrod - NRAO  19 element focal plane array (FPA) feed built by the BYU Radio Astronomy Lab was mounted on the 20 meter dish antenna at the National Radio Astronomy Observatory (NRAO) in Green Bank, WV and used for experimental observations from Oct. 31 to Nov. 7, 2007  FPAs allow electronic beamsteering for rapid sky surveys and adaptive cancellation of unwanted interfering signals that can disrupt sensitive astronomical observations  Deep space sources were detected and signal levels were used to measure performance of the FPA  Adaptive signal processing was used to cancel interfering signals successfully  These results lay the groundwork for a future array feed that will improve scientific observation capability for radio astronomy  This project is funded by the National Science Foundation

FPA with receiver system, fabricated at BYU and installed by BYU students and NRAO staff at Green Bank in front end box to prepare for mounting on 20 meter reflector Mounting the front end box and FPA on the Green Bank 20 meter reflector.

Cygnus A – very bright source used for calibration of the array. Received power is shown as the dish is steered in steps across the astronomical source. The beamformer curve shows increased sensitivity through array signal processing. Virgo A – weaker source. The detected signal level is used to measure the sensitivity of the FPA and compare performance to models. First observations with the BYU/NRAO 19 Element FPA