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Ratio Imaging: Multi-Frame Ratio
This script performs ratio imaging with the CCD37-10 CCD. Only three small subregions are needed, but to
get a good statistical base for the images, you must take a sequence of 100 identical exposures. The subimage
setup is:
CCD37-10
Image Array---->
These coordinates are INCLUSIVE. 300,5 to 400,25 is a region of 101 serial columns and 21 parallel rows.
This experiment swings in a filter (relatively slowly), sends a trigger pulse, exposes for 100 milliseconds, reads
out, then repeats.
H/W A:
experimental hardware goes to first position, sends trigger pulse,
H/W B:
the first position runs for 100 milliseconds,
H/W C:
change filters (about 40 milliseconds of delay)
H/W D:
the second position runs for 100 milliseconds
H/W E:
change filters (about 40 milliseconds of delay), loop back to A
CCD A:
prepare for exposure, clear CCD, wait for trigger...
CCD B:
expose for 100 milliseconds
CCD C:
shift_image_to_storage, readout, clear CCD, wait for trigger...
CCD D:
expose for 100 milliseconds
CCD E:
shift_image_to_storage, readout, loop back to A
The only problem is that you cannot use a signal to differentiate between CCD B and CCD D. In the future,
camera hardware might be enhanced so that it produces a flash signal in CCD E. Then you would use the
enhancement to trigger step H/W A.
script_begin();
shutter_open();
loop_begin(200);
clear_parallel(4);
clear_until_trig();
expose(100);
shift_image_to_storage();
shift_mode_s();
shift(37);
pixel_readout(300,101,1, 21,1);
pixel_display( 101, 21 );
pixel_readout(175,146,1,265,1);
pixel_display( 146, 265 );
shift(9);
pixel_readout(380, 61,1,265,1);
pixel_display( 61, 265 );
loop_end();
shutter_close();
script_end(1);
NOTE: The CCD37-10 has a 512x512 image array, but a 512x544 storage array. Discard (5+32) rows to move
region 1 to the serial register.
16 Advanced Camera Operation Manual
+--------------------------------------------+
|
###
|
###
|
#####
|
#####
|
######
|
######
+--------------------------------------------+<-- origin point: 0,0
storage array
/* SEQUENCE OF 100 IMAGE PAIRS(200 total loops)
/* CCD A&C: make sure CCD is cleared
/*
/* CCD B&D: expose with this filter
/* takes 1.23 msec, shift image under mask
/* CCD C&E: READOUT...
/*
/*
/*
/*
/*
/* leave CCD in continuous clear mode
s1,p1
| <-- region 3
380,300
|
| <-- region 2
175,26
|
| <-- region 1
300,5
|
clear until the experiment is ready
move REGION 1 up to serial register
s1:s2 of 300:400 is 101 total pixels
actual size of the region
REGION 2 is at the serial reg
move REGION 3 up to the serial regist*/
s2,p2
440,390
320,290
400,25
*/
*/
*/
*/
*/
*/
*/
*/
*/
*/
*/
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