Camera Operation
The camera is operated via a Java-based GUI.
Since the sky flux dominates the total photons received by the detector, integration times for the detector (called frame times in MIRAC jargon) have characteristic times for each filter. The central value should be kept between 6000 and 10000. The table below lists these typical values.
Typical frame times used at the MMT:
| Wavelength |
Frametime |
Level |
Magnification |
| 7.9 |
12 |
Low |
1.45 |
| 8.7 |
16 |
Low |
1.45 |
| 9.15 |
28 |
Low |
1.45 |
| 9.8 |
16 |
Low |
1.45 |
| 10.55 |
16 ms |
Low |
1.45 |
| N |
16 |
High |
1.45 |
| 11.1 |
4 |
Low |
1.45 |
| 11.86 |
12 |
Low |
1.45 |
| 12.52 |
8 |
Low |
1.45 |
Once a frame time has been selected, a chop speed of 1-5 Hz is typically used. A total integration time of approximately 30 s is used, in chop-nod mode. If 1 repeat is used, the user will end up with one 4-frame FITS file that has two chops and two nods for each file. The double subtraction of these frames provides the basic unit for further data reduction.
Advanced/Engineering Control
type “help” in command window.
‘string sift gives a list of commands with “string”
‘command show gives a short description of “command”
Taking flats with MIRAC
-
The telescope is pointed over to 30 degrees elevation.
-
The dome is closed, and 20 x 1 second exposures per filter are taken.
-
Open the dome and repeat the exposures.
MIRAC-BLINC User Manual
Comments