VLA D-configuration mosaics of relatively small fields of Galactic H I emission reveal complicated filaments and structures on all angular scales. With an ultra-compact antenna configuration it will be possible to survey H I in large parts of the Galactic plane with an angular resolution of and a velocity resolution of 0.5 km/s in a very short time. A survey covering one quadrant and 10 degrees of Galactic latitude would take only 120 hour of observing to complete. A high resolution, fully sampled survey of Galactic H I would provide an important data base for: i) modeling gas dynamics in the Galaxy; ii) comparing H I with molecular gas, allowing detailed modeling of the conversion between atomic and molecular gas in molecular clouds or photodissociation regions; iii) comparison with continuum emission, possibly allowing a distance determination to continuum features if an H I/continuum correlation is found; iv) the study of the interaction between violent events in the disk - SNR, disk blowout events, H II regions - and H I.
Technical requirements include: