It should as far as possible be unrelated to activity and active regions. As often as well developed and stable diffuse regions are available at and beyond the limb. Each radial scan should be progressively outwards in 60 steps of 10 arc sec. Each radial scan would occupy 250 minutes and so total coverage of the region could be spread if necessary over a period of days. Similar to JOP 28 for Streamers.
Lines provide a wide range of temperature sensitivity together with some density sensitivity.
I line is observed to ensure co-registration. Line selections to emphasize similar temperature range to CDS but with the aim of identifying non-thermal broadening in the emission lines.