An array, on the other hand, can yield images that reveal either large or small scale structure without having to alter its total size. To accomplish this, astronomers use different portions of the total data obtained in a single observing run. One set of baselines reveals large-scale details, while the smaller scale features are imaged using data from a different set of baselines. In summary, then, an array's spatial resolution allows scientists to extract different levels of detail about an object. A simple relationship holds between baseline length and spatial resolution.
Long baselines permit high resolutions, and therefore reveal smaller scale structures.
This image shows small scale structure in the galaxy, M82, and was obtained using data from only the larger baselines in the BIMA array. Large Scale Structure in M82 Generated from data taken during the same run, but from only the shorter baselines, this image shows large scale structure in M82. With a total of 12 dishes, the BIMA array would comprise of 66 baselines. Also, its new configuration will provide for still longer baselines. Together these two features will translate into improved image quality and spatial resolution.