TNG-MAN-HAN-0003
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The toggle must be done before the start of the computation of the centroid or within
the 5 seconds delay.
When the autoguide starts, the ‘Field Stabilization’ panel shows two images:
1.
The current acquired image, where are shown:
o
The current image acquired by the AG camera
o
The fiber position (blue circle)
o
The mask (green circle)
o
The centroid bar (red bar)
o
The compass (yellow)
2.
The Integrated Image box
This image shows an integrated image, used by the AG core to calculate the position of
the fiber.
3.7.2
Parameter for the acquisition and centroid computation
The AG system sets the main parameter for the best AG functioning, however, in case of poor
sky condition, weak star signal or other reason, some parameters adjustment may be
necessary.
In case of error of poor performance of the guide, the top bar turn from green to red or to
orange. In this case, look to the stabilization status panel to verify where is the problem and
then changes the value of the affected parameter.
The parameter that can be adjusted are (see the Autoguide manual Error! Reference source
not found. for more details)
Exposure time
Can be increased if the signal of the current image is weak
Radius mask
Can be adapted to the condition of the signal or shape of the star in the current
acquired image.
Fiber Mode
Depending on the problem, the OT can change the reference where the AG guide: The
Integrated ref. position, Manual ref. position and Default ref. position Error!
Reference source not found..
Offload
Enable/disable the OFFLOAD (the offload is the offset, sent to the TCS, every fixed
amount of time).
3.7.3
Corrections
When the AG is active, it always compute the centroid of the star. These corrections can be
disabled by the TO to avoid the system change the position of the star in the AG camera field.
The button Correction applied allow the user to toggle the AG between Correction applied and
correction skipped.
This option is used when the OT is changing some parameter to increase the centroid
algorithm performances or when the OT is moving manually the telescope to maintain or put
the star into the desired position (fiber position or special point of the observed object).
