When requesting WIYN observing time, please use the following rules to account for the observing overhead required to execute your program. That is, your total requested program time should include your estimated total integration time and your estimated total overhead time.
Important 2hr Queue Note: You must fit your entire program into two (2) hours maximum. However, we will absorb some of the overhead for your program. Where appropriate, this is noted in italics.
You must add 2.5 minutes for every requested exposure. This overhead charge compensates for the CCD read-down time. For example, if you are requesting six program exposures, please increase the total requested time by 15 mins. Two-Hour Queue proposers: you get three (3) "free" readouts.
You must add five (5) minutes for every requested target. This overhead charge compensates for the target acquisition time. For example, if you request four target fields, add 20 mins to your total requested time. Two-Hour Queue proposers: you get two (2) "free" targets acquisitions.
You must add 45 minutes per Hydra fiber configuration (except when using the echelle grating, as discussed below). This overhead compensates for fiber positioning time (roughly 25 - 30 mins) and calibration time (roughly 15 mins for most gratings). Two-Hour Queue proposers: you get one (1) "free" fiber configuration.
When using the echelle grating, please add 60 minutes per Hydra fiber configuration.
Programs that require photometric calibration should add two (2) hours for every eight (8) hours of program (integration+overhead) time. Note that this is an underestimate of the actual time required but we always try to spread this overhead over several projects whenever possible. Two-Hour Queue Imager proposers: photometric calibrations will not be obtained unless your program is compatible with highly-ranked long imaging programs that require calibrations, or the calibrations fit within the 2-hour time limit of the program.
Hydra and DensePak programs which require night-time radial velocity standards must add 15 mins per standard. If using the echelle grating, please add 30 mins per standard.
We will continue to absorb all focusing overhead for now.
Questions about these overhead estimates should be directed to Abhijit Saha (asaha@noao.edu).
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Last Updated: 8/2/99, wiynq@noao.edu