reduce the demodulated data from the switches of an exposure into
the exposure result SCULIB_REDUCE_SWITCH
For a SQUARE chop-function -
switch 1 has the object in the R beam of the ‘middle’ projected bolometer and in the L beam of the
‘right’ bolometer.
switch 2 has the object in the L beam of the ‘middle’ bolometer and in R beam of the ‘left’
bolometer.
For a TRIPOS (3-position) chop-function -
switch 1 has the object in the M beam of the ‘middle’ bolometer, in the L beam of the right and the R
beam of the ‘left’.
switch 2 has the object in the R beam of the ‘middle’ bolometer and in the M beam of the
‘right’.
switch 3 has the object in the L beam of the ‘middle’ bolometer and in the M beam of the
‘left’.
The reduction method depends on the number of switches taken per exposure, the chop function used and the projected beam that the bolometers are assumed to be in.
SWITCH_PER_EXP = 1
CHOP_FUN = SQUARE (SCUBAWAVE or RAMPWAVE)
left bolometer = BAD (was never looking at source), weight = 0.0
middle bolometer = switch 1, weight = 1.0
right bolometer = - switch 1, weight = 1.0
CHOP_FUN = TRIPOS
left bolometer = - 2
switch 1, weight = 0.5
middle bolometer = switch 1, weight = 1.0
right bolometer = - 2
switch 1, weight = 0.5
SWITCH_PER_EXP = 2
CHOP_FUN = SQUARE
left bolometer = switch 2 - switch 1, weight = 0.5
middle bolometer = (switch 1 - switch 2) / 2, weight = 1.0
right bolometer = switch 2 - switch 1, weight = 0.5
CHOP_FUN = TRIPOS
left bolometer = - 2
(switch 1 - switch 2), weight = 0.5
middle bolometer = 2/3
(switch 1 - switch 2), weight = 1.5
right bolometer = -2/3
(switch 1 - switch 2), weight = 1.5
SWITCH_PER_EXP = 3
CHOP_FUN = SQUARE
error
CHOP_FUN = TRIPOS
left bolometer = -1/2
(2 switch 1
- (switch 2
switch 3)), weight = 2/3
middle bolometer = 1/3
(2 switch 1
- (switch 2
switch 3)), weight = 1.0
right bolometer = -1/2
(2 switch 1
- (switch 2
switch 3)), weight = 2/3
Any other combinations of parameters will give rise to an error report and the routine will return with bad status.