WFI Overheads
The following is the list of overheads for the WFI:
The WFI Overheads | |
---|---|
Pointing the Telescope | Over large angles, ~3000 arcsec/sec Typical pointing time between 30 seconds and 2 minutes |
Changing Filter | 45 seconds + 2.5 seconds * difference in position number of the filters e.g. Changing from filter position #4 to filter position #12 45s + 2.5*(12-4) = 65 seconds |
Software Overheads | |
Aquiring a Guidestar ** | <1 minute |
Detector Readout | 27 seconds |
File transfer to instrument control workstation and RTD | 45 seconds (i.e. 27 seconds for readout + 18 seconds) |
Focussing | ≤10 minutes |
Move to Gap Template | 2 * [Exposure time + 45 seconds (readout and transfer) + ~1 minute (find star and set coordinates)] At least! (depends on how accurate you want the positioning) |
**NOTE: If you have COMBINED OFFSET = F (i.e. if you have large offsets between each image), this overhead applied for each image within your dither sequence.