LMI: Status (Updated Nov 25, 2012)
LMI is now on the telescope and being commissioned. We are running with the "engineering-grade" chip", learning a great deal. A small version of the "first light" image of NGC 891 can be found above; click on it for a higher res version.
A complete set of our pretty pictures can be found by following the Gallery link below!
In late June, e2v sent us the two CCDs
we've been patiently waiting for, a grade 5 "setup" device and
the grade 1 science chip. The specs for the grade 1 science device
can be found here. According to the spec sheets, the grade 5 device is nearly as good as the grade 1, with similar DQEs and other characteristics. (The peak DQE of the grade 1 device is 97%, thanks to the special AR-coating.) The grade 5 device was put into the dewar in July for testing and tweaking, and the camera was taken out and put on the instrument cube Sept 4. Bad weather prevented much by way of on-sky tests until September 12. We will continue commissioning,replacing the grade 5 device with the grade 1 device in November. Here are some things we've learned.
Commissioning Activities
- Characterize read-noise and gain for both devices
- Check linearity
- Measure tilt of device wrt to focal plane and correct, if needed
- Test flat fielding (calibration lamps vs twilight skies)
- Obtaining count rates with both Grade 5 and Grade 1 devices.
- Tune software
- Refine Exposure Time Calculator (ETC)
- Write documentation
For the long term:
- Complete ADC study; identify funding source; build (Completion: T+5 years
after first light?)
- Identify other "standard filters"; obtain funding, buy.
These results made use of the Discovery Channel Telescope at Lowell Observatory. Lowell is a private, non-profit institution dedicated to astrophysical research and public appreciation of astronomy and operates the DCT in partnership with Boston University, the University of Maryland and the University of Toledo.
