HI emission and absorption in the Southern Galactic Plane Survey

We present preliminary results from the Southern Galactic Plane Survey (SGPS) Test Region and Parkes data. As part of the pilot project for the Southern Galactic Plane Survey, observations of a Test Region (325.5 degrees less than or equal to 1 less than or equal to 333.5 degrees: -0.5 degrees less than or equal to b less than or equal to 3.5 degrees) were completed in December 1998. Single-dish observations of the full survey region (253 degrees less than or equal to l less than or equal to 358 degrees \b\ less than or equal to 1 degrees) with the Parkes Radio Telescope were completed in March 2000. We present a sample of SGPS H I data, with particular attention to the smallest- and largest-scale structures seen in absorption and emission. respectively. On the large scale, we detect many prominent H I shells. On the small scale, we note extremely compact, cold clouds seen in H I self-absorption. We explore how these two classes of objects probe opposite ends of the H I spatial power spectrum.