C100/CCD Observing Procedures
1. Accessing Data Acquisition Computer (Clarity)
- Username: obs100a (or obs100b)
- Password: check with the staff
- Open an xterm window
- cd DATA/
- mkdir 20050914_15 (e.g.)
- cd 20050914_15
2. Start Detector Control Window
- In xterm type 'ccd &'
- Select CURTAIN
- Select TEK5
- Overscan = 32
3. Dome Flats
- Turn OFF platform lights
- Turn ON quartz light and adjust voltage
- Set Gain=3
- Set exptime, Imtype=flat, Loop=7, and take a sequence of flat frames
- Exposure times for CSP filters:
- B: 20 sec (12500 cts/pixel) (voltage=480)
- V: 15 sec (12500 cts/pixel) (voltage=400)
- g': 20 sec (12000 cts/pixel) (voltage=400)
- r': 7 sec (13000 cts/pixel) (voltage=375)
- i': 6 sec (13000 cts/pixel) (voltage=350)
- u': Take SKY FLATS
For old filters that the CSP no longer uses:
- R: 10 sec (12500 cts/pixel) (voltage=350)
- T2: 5 sec (15000 cts/pixel) (voltage=350)
- z: 5 sec (11000 cts/pixel) (voltage=350)
When the sequence of flats is complete turn OFF quartz lamp
Set exptime=0, Imtype=zero, Loop=10, and take a sequence of bias frames
4. Telescope Pointing
- Point to a bright star
- Take direct image
- Compute telescope offset to place star near CCD center at (1300,1024), avoiding bad column
- Ask the NA to CSET the telescope
5. Telescope Focus
- Point to a bright star
- In CCD window set Loop=7, set filter=V, Exptime=10, and use FOCUS (not START) command
- Imexamine the image (as of March 5th, 2008 best focus is ~4810)
6. Observing
- Changing the gain during the night is not recommended since it's easy to forget to reset it.
- Set Imtype=object
- Focus offsets (as of March 5th, 2008):
- B: +5
- V: 0
- u': -40
- g': -45 to -50
- r': -35
- i': -35
- for old filters
- U: +10
- R: +5
- T2: -52
- z: +30
7. Before going to bed
- Data should be copied over to csp3: e.g.
scp -r ../20080304_05/ observer@csp3:/data/opt
where observer is user name of the observer
- After finishing the darks turn OFF monitors in control room
mstritzinger@lco.cl