\contentsline {chapter}{\numberline {1}INTRODUCTION}{2}
\contentsline {chapter}{\numberline {2}TECHNICAL OVERVIEW}{4}
\contentsline {section}{\numberline {2.1}Primary Goals for the VLA Expansion}{4}
\contentsline {section}{\numberline {2.2}Components of the Upgrade}{5}
\contentsline {subsection}{\numberline {2.2.1}The Ultra-Sensitive Array}{5}
\contentsline {subsection}{\numberline {2.2.2}The A+ Configuration}{7}
\contentsline {section}{\numberline {2.3}Antenna and Receiver Improvements}{7}
\contentsline {subsection}{\numberline {2.3.1}Improved Low Noise Receivers}{7}
\contentsline {subsection}{\numberline {2.3.2}New Observing Bands at the Cassegrain Focus}{8}
\contentsline {subsection}{\numberline {2.3.3}New Prime Focus Systems}{9}
\contentsline {subsection}{\numberline {2.3.4}Sensitivity Goals}{9}
\contentsline {section}{\numberline {2.4}A New LO/IF Transmission System}{10}
\contentsline {section}{\numberline {2.5}A New Correlator}{10}
\contentsline {section}{\numberline {2.6}Improved Surface-Brightness Sensitivity}{13}
\contentsline {section}{\numberline {2.7}High Angular Resolution---The A+ Configuration}{15}
\contentsline {subsection}{\numberline {2.7.1}Example imaging with the A+ configuration}{18}
\contentsline {section}{\numberline {2.8}On-Line Computing}{21}
\contentsline {section}{\numberline {2.9}Other Capabilities}{21}
\contentsline {chapter}{\numberline {3}NEW SCIENCE WITH THE ENHANCED VLA}{22}
\contentsline {section}{\numberline {3.1}Imaging-Spectroscopy of Solar Radio Bursts}{22}
\contentsline {section}{\numberline {3.2}Bistatic Radar Observations of Planets and Minor Bodies}{22}
\contentsline {section}{\numberline {3.3}High-resolution Imaging of Thermal Emission}{23}
\contentsline {section}{\numberline {3.4}Imaging Protoplanetary Disks}{23}
\contentsline {section}{\numberline {3.5}Transient Phenomena}{24}
\contentsline {section}{\numberline {3.6}Extragalactic \hbox {H\hskip 1truept{\sc i} }Surveys}{24}
\contentsline {section}{\numberline {3.7}Clusters of Galaxies}{25}
\contentsline {section}{\numberline {3.8}Objects at High Redshift}{25}