CONNECTING TO THE BIAS COMPUTER AND GETTING STARTED

BIAS checklist
 

The BIAS computer is an old PC running the acquisition system.

LOGIN:
username : dfosc

Password lasilla

Click on BIAS icon. It will open various windows (BIAS CCD Status, BIAS CCD control)

FIRST CHECKS:
CCDtemp: -120
P_DEWAR: 2.0E-06 mb
GAIN: hi_gain
enough Mb free
FILTER A: 0 (free)
FILTER B: 5 (Gunn_I)

STARTUP:
run start.bat (define amplifier and select size and position of image)

DOME FLATS:
object test
exp 2: check about 40000 counts with intensity at 100
object DomeFlatI
mexp 2 50
On cloudy night, do a sequence of flats in B V R I:
B: intensity at 200
object DomeFlatN
mexp 10 50
V: intensity at 100
object DomeFlatV
mexp 10 50
R: intensity at 100
object DomeFlatR
mexp 3 50

BIASES:
object Bias
mdark 0 50

FOCUS:
Adjust Offset Steps in Telescope Constants section to 10 arcsec
Put telescope in Guide mode
focus 10 (exp. time)
15250
25
9
telfocus 15300 (at 12 deg)
it varies with temperature (10 units per degree) and telescope position
variation with filter (checked May 16, 2006):
R=I-85, V=I-60, B=I-85, U=I-140

Some other useful BIAS commands:
afilter 0    (set the A filter wheel to free position)
bfilter 5    (set the B filter wheel to I filter)
imexa to measure star profile (a)