This paper presents results of investigations of the relationship between optimal image resolution and associated sky-coverage for ionospheric tomography. Several measures of the variation of image information content as a function of resolution are presented for understanding the trade-offs between information content and computational resources. A new quantitative description of imaging geometry that enables sky-coverage analysis for this limited information tomographic system is introduced here. This paper also presents examples of commonly encountered nonideal system geometries, diagnosis of associated image artifacts, and improvements achieved by minor logistical modifications to the imaging system. ¿ 2000 American Geophysical Union