Aligning LWS

Aligning LWS

Set up LWS in L band imaging mode

	grating		mirror
	aperture	open
	filter		L
	window		out or in
	sector		home/open

Acquire V = 1 or brighter star, suggestion: IRTF standard. No guiding is required.
Set chopping on at 20" throw and center star on LWS.
Apply +175 nm pmfm and verify that individual segments are discernable and all are within the LWS field of view. Adjust pmfm as needed. If seeing is poor, more pmfm can be used but offsetting the telescope will be required to check the outer segments.
Verify alignment of LWS filter wheel.
```
	s filraw 		(should be 320000)
```
move filraw in steps of 2000 until segments on one side of pmfm image (tel pupil) become vignetted. example
```
	m filraw = 322000 
	m filraw = 324000
```
then check the other side
```
	m filraw = 318000
	m filraw = 316000
```
verify value of filraw that corresponds to best filter alignment and note value. Values for filname can be adjusted later in ~lws/v3-0/cfg/lws_filter.config file on the summit account.
Verify that all 36 segments are visible in pmfm image on LWS. Offset the telescope to verify outer segments. This helps in cases when LWS internal vignetting may be effecting the image and when larger values of pmfm are needed. Save pmfm LWS image. note: 1 outer corner segment may be distorted and not as bright other corners. This is acceptable and is similar to previous best efforts. If seeing is very poor and individual segments are not discernable, save an image of the pupil hexagon image but do not proceed with any adjustments unless the errors are extreme, say on the order of 1/4 to 1/3 of the primary.
If alignment is necessary, an instrument engineer / technician will need to manually adjust the two LWS mounting bolts while riding in the telescope. This procedure should be considered highly dangerous and only technicians specifically trained are approved for performing it. Realtime communication (telephone headset) is required between the LWS operator and technician.
LWS should be rotated UP in the FCM, (I think this is -90 deg)
Engineer should get in position using proper safety gear (not covered here) and telescope should point to a star not higher than 50 deg elevation.
Setup per steps 1-5 above.
Verify adjustments of AZ EL coordinate system with engineer. Adjusting two bolts in the same direction should make an EL adjustment and adjusting the two bolts in opposite directions should move in AZ.
Continue adjustment until LWS is locked down tight and all 36 segments are in pmfm image.
Save pmfm data of final adjustment.
Let the engineer get off of the telescope.(optional)