The envcfg tab

The second tab defines the restrictions that will be used to decide if the OB can be executed at current observing conditions. Refer to the Sect. 2.1.4 for their explanation.

The cells regarding the seeing and transparency can be edited, but only to relax the values approved in Phase 1. The Phase 1 values will be sent in the AL, and are also given in proposal tab. Those cells cannot be edited.

The column Code is an identifier which can later be used to refer to a particular set of conditions. One should set the maximum allowed Seeing, in arcsec. Next, define the sky brightness in Moon, using dark/gray/dark+gray (HSC runs are not allocated during bright time). Then, give the minimum allowed separation from the Moon (Moon Sep, in degrees, 30 for “dark” and not smaller than 30 for “gray” or “dark+gray”), and the sky transparency (Transparency, from 0=“cloudy”, to 1=“completely clear”). If any of the values in Seeing or Transparency are more strict than the Phase 1 criteria, an error message will appear.

From S19B, Seeing must be one of 0.8, 1.0, 1.3, 1.6, and 100 (i.e., no constraint) in arcseconds. We also recommend the following seeing values for each GRADE: equal to or larger than 1.0 for GRADE A; equal to or larger than 1.3 for GRADE B; and equal to or larger than 1.6 for GRADE C and F. Similarly, Transparency must be one of 0.7, 0.4, 0.1, and 0 (i.e., no constraint). The tolerance factor we use for these constraints is such that the numbers will be rounded off to the first decimal place (for example, seeing (transparency) 0.84 (0.65) for an OB requesting 0.8 (0.7) will be considered as good). Note that we define transparency as the total throughput including the telescope and instrument, and not just through the atmosphere.

PIs of the Filler proposals must use values equal to or larger than 1.3 in Seeing and/or equal to or lower than 0.4 in Transparency.

There are two optional columns, Lower Time Limit and Upper Time Limit to define the lower and upper time limits of a time window in the case of the time critical program. The PI can leave these blank if there is no time constraint other than the standard visibility defined by the coordinates. The format follows the standard ISO 8601 regulation, e.g., YYYY-MM-DDThh:mm:ss. The default timezone is UTC. For example, the following forms can be permissible: YYYY-MM-DDTHH:MM:SS, YYYY-MM-DDTHH:MM, YYYY-MM-DD HH:MM:SS, and YYYY-MM-DD HH:MM. Different timezones can be specified by providing an offset from UTC, e.g., YYYY-MM-DD HH:MM-10 for Hawaii-Aleutian Time Zone (HAST).

Finally, one should place any additional comments in the last column (Comment). More than just one set of constraints can be defined, but none of them can be more restrictive (lower seeing, better transparency, etc.) than the ones in the proposal.