LIRIS Overheads

Filter change overheads (sec)   to from z J H Ks z 0 18 63 47 J 80 0 58 43 H 34 39 0 68 Ks 54 54 55 0 average: ~50 seconds Changing imaging and spectroscopic modes (sec)   to from image (J) spec (zj) spec (hk) image (J) 0 78 45 spec (zj) 43 0 69 spec (hk) 78 56 0 average: ~60 seconds representative for other filters as well. Changing imaging, polarimetric and coronographic modes (sec)   to from limage j lipol j lcor j limage j 0 71 79 lipol j 45 0 53 lcor j 47 74 0 average: ~60 seconds representative for other filters as well On-target Movement overheads:   12" dithering offset (imaging, tracking): 8 24" dithering offset (imaging, tracking): 11 12" nodding offset (spectroscopy, tracking): 12 12" nodding offset (spectroscopy, guiding): 33 Rotator angle from 0 to 90 or 90 to 0 degrees: 120 Exposure related overheads:   clear-reads (default N=3. Only before first exposure at each new position.) Nx0.8 Imaging read-out time, mndr 1 1 (default): 2         mndr 2 1: 3 Spectroscopy read-out time, mndr 4 1 (default): 5         mndr 8 1: 11 Time until image is displayed after readout: 4 Time until image is saved after readout: 4 Time until you get the prompt back after readout: 2 Please note that while dithering or nodding, after the last exposure is taken at a given position, the chip is readout while moving to the next position, so only the larger overhead (movement or readout) applies.