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WORKING WITH NEW PFIP
PFIP (Prime Focus Imaging Platform) is currently undergoing major changes to the camera hardware. This page is likely to change frequently as commissioning progresses.
The documentation for the old PFIP camera can be found here
The new PFIP camera consists of an e2v, 4k x 4k CCD with increased QE at red wavelengths (peaking at 900nm). The FOV is increased to 18' x 18' with a pixel scale of 0.27 ''/pix. More information on Red+4 can be found here. PFIP is an imaging platform that replaces the secondary mirror.
To zeroset absolute:
The light to the autoguider is fed by a fiber, giving a FOV (25"x25"). Use in twilight to define the AG window.
From the observer interface the autoguider probe can be moved, the control GUI starts using the command from the SYS or TO prompt. The obssys brings up one such GUI on WHTICSDISPLAY but the TO can bring up another one on the taurus session. It is useful for controlling Autoguider probes and focus. The probe response is faster on this GUI than when using the command line. To move from the command line use:
The diagram below shows the direction in which the star moves on the science detector for a given X or Y telescope movement. Rotator centre is at aproximately 2074 2072.
Filling the cryostat:
From the TCS:
When the telescope has stopped change to ENGINEERING mode and go up to the telescope and move it manually to AP2. After filling the cryostat move the telescope out of access park by pressing ZP. Go back to the control room and switch back to COMPUTING mode.
Rotator centre and Calibrate procedure:
PFIP usually observes with a Rot Sky 0,
so it is important to be sure that the rotator doesn`t reach the limit switch.
Open a terminal, logon as whtobs and type 'obssys' followed by the correct option. From this TO-window the probe is moved with command 'agprobe' and the guider focus with 'agfocus'. Focus was around 10200 (27/09/13). 'pfip_status' lists the status.
GSS search results require little or no correction, even when an APERTURE OFFSET is included. GSS was 100% correct at ROT SKY 0 including apertures. Other angles than ROT SKY 0 have not been tested, but there is a good chance that GSS will also work there.
Dithering while keeping the guide star:
The observer will usually use the OFFSET ARC command to make a dither pattern. Even a dither of 10 arcsec will require adjusting the guide probe position because the star image is so large compared with the Guider field (unless you are clever enough to place the star in the correct corner and make a 4-point square dither pattern). Basically for every 10 arcsec offset, you need to move the probe 600 units. A telescope offset in +X will require a probe offset in +X, but a Y offset requires the probe to be offset in the opposite Y direction to recapture the star.
The data may not all fit on one 4.7 GB DVD. Even 4.5 BG on disk will not write to 1 DVD.
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