![]() |
Hokupa'a Observing Overheads |
Each new science target may incur the following overheads:
Overheads are estimated based on commissioning results as well as early QuickStart observations.
Example: As an example, 30 min of on-source integration comprised of three sets of 3*50sec exposures at each of four dither positions, separate sky frames using the same dither sequence and interspered with the science observation after each complete four position cycle, plus observation of a PSF star for photometry and deconvolution, would take about ~140 minutes.
30 minutes (Target acquisition) 20 (PSF calibration) 12*0.5 (on-source offseting/dithering) 24*0.25 (on-source detector readout) 30 (on-source time) 12*0.5 (on-sky dithering) 24*0.25 (on-sky detector readout) 30 (on-sky time) 6*0.5 (switching between source and sky) ______________ _____________________________ 137 minutes TOTAL
If the target is extended or lies in a very crowded field then separate sky exposures would be required.
Last update 24 August 2000; Mark Chun