The inscfg tab

This tab defines the instrumental parameters used during an observation, such as filter, exposure time, or dithering pattern. The Code column defines an identifier which can later be used to refer to a particular set of parameters. Instrument and Mode should be kept at “HSC” and “imaging”, respectively. One should set the Filter, choosing from g/r2/i2/z/Y, or by typing the name of an NBF. Only the new names of filters should be used (i.e., r2 and i2 instead of r and i, respectively). PA is the position angle of the instrument3.5. Exp Time is the exposure time for one frame, without overheads. The number of allowed short exposures is limited, so that no more than 5 exposures of 60 sec or less are allowed within a single OB. This limit does not apply to longer exposures.

The dithering (Sect. 2.1.6) is defined by Num Exp, Dither, Dith1, Dith2, Skip and Stop. Note that there may only be one exposure on a single dither position. To set the 5-point pattern, use Num Exp=5, Dither=5, and desired values (in arcsec) of the steps $dRA$ and $dDEC$ in the Dith1 and Dith2 columns, respectively. To set the circular pattern, use Dither=N, and the desired number of steps in Num Exp. We recommend to keep this number around 5. Type the radius of the circle in arcsec as the Dith1, and initial angle $\theta $ in degrees as the Dith2. If not using dithering, set Dither=1. In such case the Num Exp column will define how many exposures will be done without moving the telescope (default is 1).

If one needs more than 5 points in the dither sequence, higher Num Exp can be set for the circular dither. However, we suggest to keep the total OB time relatively short, and it cannot be longer than 30 min (1800 sec) of on-source time. One may choose to split the configuration in two, doing some positions within the first one, and the rest within the other. For this, Skip and Stop should be set appropriately (Sect. 2.1.6). Note that Stop may not be smaller than or equal to Skip. These configurations should have different Code identifiers, but should have the same number of Num Exp, which is the total desired number of positions in the sequence, as well as the same values for all other dithering and instrumental parameters. If a single setting is used, Stop should not be changed - by default it should be equal to Num Exp.

From S21A, customized standard star calibrations are limited so that 1 exposure of 30 sec or less is allowed within a single OB.

Based on the dithering settings and Exp Time, for each configuration the spreadsheet will calculate the on-source (without overheads) and total time (with overheads of telescope slew and readout), and automatically put it in the On-src Time and Total Time columns, respectively. One should not edit these columns. In Phase 2 the readout overheads need to be included in the OBs.

Guiding=Y should be set to turn on the guiding, and N to turn it off. If one wishes to use an offset from the original position (for example to avoid having the target in a gap between CCDs), one should set it in Offset RA and Offset DEC columns, in units of arcsec.