We used the FCLS 200um aperture and a temperature of 150 K. The robofocus was at 6800. We didn't play with that. EXES was imaging through the N04679-4 filter and the ND filter. We ran with N0 D0 T0 pattern.
We first put the FCLS at the HIPO Boresight Position (more recent of the two dates - not much difference between them). We imaged with open/open/open and then the slit inserted. We then moved the FCLS to put the spot on the slit. This establishes our boresight in FCLS coordinates.
We then adjusted the filter/decker/slit wheels to make things rounder. This ended up being a 2.5 degree motion. We saw 4 degrees motion was too much, but there wasn't much difference between 2 and 3.
With the new f/d/s position, we again imaged the field, the slit, and then moved the FCLS spot to come through the slit.
The pictures below document these different cases. Each image is a combination of open and thru-slit so that the slit can be seen relative to the full field.
I used a circle drawing routine in IDL to quantify the radius and center of our circular field. I'd guess this is accurate to about 5 pixels. It'd be nice to come up with an automatic routing to do this.
Finally, the IDL journal file I used is in eE/analysis/cd22/taas/getimages.jou and the data are all in cd022_2015sep/5.
First image has FCLS at HIPO Boresight: 45.75, 31.112 (yellow cross). This lands (for this echelle angle) on EXES pixel 462, 445. The green circle roughly encompassing the EXES Field is centered at 570, 498 and has a radius of 369.
Second image has FCLS on our slit. FCLS coordinates are (x,z) = (48.35, 24.4) and the EXES pixel is (x,y) = 596, 513.
Third image is after we moved slit/decker/filter by +2.5 degrees (-2.5 for decker). It looked like 2 and 3 degrees changes were equally round, but 4 degrees was starting to clip. The FCLS spot is at the same place (x,z) = (48.35, 24.4). The spot on EXES detector is one pixel different: (x,y) = 597, 513. The new center of the circular FOV is at EXES pixel (x,y) = 491, 482 and the radius is 398 pixels. Unclear how much of the radius could be caused by different level for where the circle starts.
This last image has the FCLS at (x,z) = 45.95, 27.9 and the spot comes in at the EXES detector (x,y) = 512, 493.
Some Distances:
Between FCLS spot on slit in flight configuration and after moving s/d/f:
In FCLS coordinates: del_X = 2.4, del_Z = -3.5, => 4.24 (mm) => 17.7" (4.16" per mm from TAAS to SOFIA).
In EXES coordinates: del_X = 85, del_Y = 20; => 87 pixels => 17.9" (use 0.206" per pixel)
Not sure if this was all the boresight motion we had or not. If we had the notes from before other flight series, we'd be able to check compared to FCLS.
Between the center of the circle in flight and after moving s/d/f:
In EXES pixels: del_X = 79.4, del_Y = 15.7, => 81 pixels => 16.7"
