First night NOTCam goes on telescope

The following tests are to be made on the first afternoon/night after NOTCam has been mounted on the telescope. These tests are supposed to be carried out and analysed by staff, and the tables on this webpage should be updated.

List of content in this document:

Check reset level
Optical alignment of wheels
Measure pinhole positions
NOTCam Quality Control (detector monitoring)
Rotation centre measured on the sky
Instrument alignment (measured on the sky)

During daytime

Start up the software according the instructions in the NOTCam Cookbok, and make sure you have valid entries in the optical path (status on the UIF being green, not red). Note that the setup script notcam.setup-ima crashes if you have the optical elements initially set to "Initialized" or "Not-initialized". Set the wheels manually by clicking on the menus in the UIF and then on the item of your choice. As soon as these positions are valid (green), the setup script notcam.setup-ima can be run.
Check reset level. This is being done automatically by the QC script since November 2010, and strictly speaking you don't have to go through this test.

If you want to do it manually, it simply consists of finding the count level on the reset readout in each of the four quadrants. Take a simple exposure or a dark with the command dark 0. Open up an IRAF session with a DS9 on Florence, and display the reset image
- displ /data/notcam/"filename"[2]
- use imexamin and m to find the median value
For the new Science Array the reset image level should be 6000 ± 1000 ADU in the centre of each quadrant. If the median is less than 3000 or more than 9000 ADU, the dc-offset voltages for the corresponding quadrant should be adjusted. You have to login as staff on the instrument computer and edit a script in the NOTCam directory of instrument scripts /home/softremote/inst-scripts/NOTCAM/ that is called "notcam.volt_newpcb_max". Note that there are three different type of voltages and you should only adjust the ones called "dc-offset" that are set with the commands:
```
notcam.sendcamcmd @VBLB00+03566
notcam.sendcamcmd @VBLB01+03532
notcam.sendcamcmd @VBLB02+03410
notcam.sendcamcmd @VBLB03+03524
```
for the 4 quadrants numbered from 0 to 3. Comment out the old values and try adjusting the level by changing the 4 digit number at the end of each command . Start by changing only 10 units. Run the script, take a new test exposure, measure the new reset level, and iterate.

Fig 1: A reset image obtained on the commissioning day of the new science array (SWIR3, 13/12-2007).
Optical alignment of wheels. This is not necessary every time NOTCam is mounted, typically after every opening of NOTCam only.

Check, using the pupil imager, that filters and stops seem aligned with the pupil. If the 15mm stop or any filter is not aligned, then update the stepper motor units in the appropriate .def files. Since Jan-2006 these files are found on marissa in the directory: /home/softremote/notcam/tcl-uif/

TBD: Write proper instructions for how to do this.

Pinhole position. Monitoring the pinhole position.

The idea is to check the internal stability of the instrument and the position of the detector whenever the 50 micron pinhole has not been moved during the opening. Note that from the 26/10-2005 until April 2006 the first science array was in.

This task is done by running the interactive SEQUENCER script notcam.pinholePosition. Turn on/off the lamp when you are asked, and use imexam to measure and note down the X,Y values for each camera. Play around with the scale on the DS9 to actually see the pinholes. NB! Note that the Argon lamp may come on very slowly. The sequencer commands to switch on the argon lamp is tcs.baffle-lamp-2-on, and to switch it off tcs.baffle-lamp-2-off. The lamp status (i.e. commanded status) can be seen on the TCS status page 31. Update the table below. NB! some minor changes to be made to the script with the new 'common DS9 display' needed (remark 7/6-09).

Date         X (WF)    Y (WF)     X(HR)     Y(HR)     Comment
--------------------------------------------------------------
2003-12-10   577.3     554.3                          SWIR1       
2003-12-11   576.0     554.0
2004-04-27   556.2     538.9
2004-06-03   554.3     539.0
2004-07-02   551.4     539.4
2005-01-21   555.1     538.9
2005-03-25   553.4     539.5
2005-04-15   551.5     540.8
2005-05-18   559.8     539.2
2005-06-15   550.1     538.6     560.1    520.8
2005-08-18   555.0     535.5     561.3    511.3
2005-10-26   575.0     538.5     582.3    514.4    SWIR2 installed 2005-10-20
2006-02-07   572.1     539.2
2006-03-15   573.6     539.3     576.0    517.4
2006-05-11   482.5     542.3     481.7    523.6    SWIR1 reinstalled 2006-05-02
2006-07-05   489.8     538.3     474.8    524.8
2007-02-24   485.7     541.8     483.9    522.5
2007-03-29   487.1     541.7     481.1    522.3
2007-04-29   483.5     541.9     476.3    521.9
2007-05-27   483.88    541.85    481.40   522.10
2007-08-28   484.02    543.05    475.75   524.23
2008-04-16   471.9     524.2     464.9    512.4    SWIR3 installed 2007-12-07
2008-05-21   470.0     525.0     460.7    508.8
2008-06-09   471.7     525.6     465.6    508.4
2008-06-12   472.4     524.9     465.7    509.4
2008-07-07   470.6     524.1     461.8    506.1
2008-07-16   470.5     523.5     459.6    506.4
2008-09-14   471.0     523.2     462.4    514.6
2009-01-07   473.4     519.0     469.6    514.4
2009-03-07   475.5     523.9     462.4    508.6
2009-04-04   469.8     523.0     459.2    514.5
2009-05-10   456.8     532.8     457.6    515.5    Opening 2009-04-20, SWIR3 touched
2009-06-07   468.1     533.8     462.5    517.7
2009-07-10   463.5     532.2     457.5    514.4
2009-09-30   467.1     531.9     466.5    515.3
2010-02-06   466.5     532.8     463.8    514.5
2010-10-28   466.5     531.7     461.1    515.1
2010-11-18   468.9     530.8     457.0    513.3
2010-12-10   468.5     530.4     466.2    513.6
2011-02-12   465.6     531.7     459.1    539.6    Opening 2011-01-10, detector plate dismounted
2011-06-10   468.1     520.6     463.7    520.2    Opening 2011-05-26, detector plate dismounted
2011-08-11   464.9     521.4     450.1    520.0
2011-10-12   462.6     521.3     442.7    519.6
2012-01-07   469.4     521.3     463.0    517.1
2012-03-01   463.7     520.8     446.6    518.9
2012-04-01   467.8     528.9     462.9    522.3    Opening 2012-03-15, aperture unit dismounted  
2012-05-01   468.0     527.7     465.8    518.9
2012-06-09   466.1     528.8     456.7    521.4
2012-09-06   461.4     529.0     443.7    520.2
2012-10-01   460.8     529.0     444.7    521.0
2012-12-17   461.98    529.83    445.34   523.67
2013-01-22   464.47    529.64    449.46   521.55
2013-02-19   461.57    530.36    447.36   518.73
2013-03-21   463.24    530.36    450.38   520.47
2013-04-25   458.68    530.42    438.80   521.98
2013-05-25   463.2     530.9     449.4    522.3
2013-06-22   464.0     530.0     452.1    521.2
2013-08-29   459.4     530.0     439.9    519.9
2013-09-14   459.2     529.1     442.5    518.6     
2013-12-15   460.04    529.36    445.03   519.28    Opening 2013-10-25, aperture unit dismounted 
2014-01-16   460.42    528.36    442.81   514.73
2014-02-13   458.34    529.58    439.02   519.52
2014-03-13   459.12    529.11 	 443.06   519.42
2014-04-04   460.09    529.27 	 444.27   518.52 	
2014-04-14   458.5     528.7 	 436.8    519.1 
2014-05-19   459.1     529.1 	 438.7 	  519.3 	
2014-06-09   462.4     529.1   	 448.4 	  519.6
2014-07-09   457.9     528.9 	 435.2 	  519.0 	
2014-08-08   463.4     529.2 	 448.8 	  518.8
2014-08-22   461.9     528.7 	 445.4 	  516.0
2014-09-03   462.9     528.8 	 449.3 	  518.8 	
2014-10-05   460.2     529.2 	 437.8 	  519.0 
2014-10-29   461.2     530.0 	 442.6 	  521.5 	
2014-11-07   463.0 	529.4 	449.7 	519.8 	
2014-11-29   457.6 	529.1 	433.0 	519.8 
2015-01-05   460.4 	530.3 	442.5 	521.5 	
2015-02-04   462.2 	529.7 	449.4 	521.6 
2015-03-05   461.6 	529.9 	445.6 	522.2
2015-04-04   463.1 	528.6 	447.4 	514.8
2015-05-01   464.8 	529.0 	452.1 	519.5 	
2015-05-29   461.7 	529.0 	441.2 	520.4 
2015-07-03   463.4 	528.9 	448.0 	520.5  
2015-08-02   459.1 	529.5 	436.7 	521.8 	
2015-09-02   459.0 	529.2 	437.5 	520.1 	
2015-09-26   462.0 	529.1 	443.7 	520.8 
2015-10-27   461.4 	529.8 	441.7 	521.4 
2015-11-23   463.7 	529.0 	445.2 	520.2 	
2015-12-22   465.4 	530.0 	450.9 	522.4 
2016-01-23   465.6 	521.4 	457.3 	500.8 
2016-02-22   460.8 	522.0 	447.5 	500.1 	
2016-03-23   465.1 	528.2 	453.2 	519.0 
2016-04-20   463.8 	528.1 	450.9 	518.3 	
2016-04-29   459.6 	528.3 	440.1 	517.9 
2016-05-21   464.8 	529.0 	453.7 	519.7 	
2016-06-11   453.4 	528.3 	422.5 	520.5
2016-07-14   462.6 	527.8 	445.7 	516.8 
2016-07-27   467.3 	528.5 	465.0 	515.9 
2016-08-11   469.2 	528.5 	466.9 	518.9 
2016-09-15   459.9 	528.3 	443.6 	518.9
2016-10-12   463.5 	528.4 	451.0 	517.7
2016-10-25   458.5 	528.2 	437.9 	516.3 
2016-11-10   459.0 	528.3 	437.7 	517.5 	
2016-11-30   468.9 	528.8 	469.6 	519.8 	
2017-01-09   464.9 	527.9 	456.7 	514.9 	
2017-02-07   464.2 	528.5 	452.8 	519.6 
2017-02-19   463.7 	529.2 	451.2 	520.3 
2017-05-01   463.9 	528.2 	449.5 	518.1 	
2017-05-24   466.2 	528.3 	457.7 	517.4 
2017-06-20   463.7 	528.3 	447.0 	518.1 	
2017-09-02   461.4 	528.7 	443.8 	518.7 
2017-10-26   463.3 	528.1 	446.5 	518.2 	
2017-11-02   464.3 	527.8 	446.2 	518.9 	
2017-12-07   470.4 	528.6 	464.6 	518.9 
2018-01-03   467.5 	528.4 	461.5 	518.2 
2018-02-16   466.1 	528.9 	456.8 	520.0
2018-03-11   465.9 	528.0 	455.1 	519.1
2018-04-17   465.0 	529.6 	447.6 	521.4
2018-05-11   470.0 	528.7 	462.3 	518.7
2018-05-26   464.9      528.4   448.1   519.3
2018-06-10   467.8      528.2   458.8   518.0
2018-06-27   464.2      526.2   449.7   514.3  Opening 15-6. Aperture unit dismounted.
2018-07-13   465.4      526.1   456.3   513.0
2018-07-30   466.1	526.7	460.3	514.5
2018-08-19   464.0      527.5   455.8   515.5
2018-08-28   465.0      526.7   454.6   514.1	
2018-09-23   465.1      526.6   454.6   513.7
2018-11-02   463.6      526.3   445.7   513.1
2019-01-29   467.7      526.5   460.1   514.1
2019-02-15   470.2      526.9   466.8   515.1
2019-03-04   471.7      526.2   468.3   513.1
2019-03-17   471.2      526.1   469.8   512.8
2019-04-09   467.8      526.5   459.0   513.0
2019-04-30   467.1      527.4   457.8   516.0
2019-05-17   464.8      526.7   451.2   513.7
2019-07-21   466.6      526.7   454.1   514.7
2019-08-17   460.2      525.2   436.0   514.0
2019-08-22   462.4      526.1   443.3   514.4
2019-09-13   465.8      524.9   456.7   510.3
2019-12-16   466.5      526.0   457.7   513.7
2020-02-05   465.6      526.4   453.0   514.6
2020-03-02   469.0      526.1   459.8   514.3
2020-03-26   467.8      526.4   456.1   514.9
2020-05-30   465.5      527.1   451.5   515.4
2020-07-08   469.5      527.3   464.2   516.3
2020-08-06   467.8      526.5   459.8   513.8
2020-09-09   469.0      527.0   466.0   517.3
2020-11-20   470.4      527.7   466.7   517.6

Detector monitoring. This should be done once every time NOTCam is mounted on the telescope, preferrably on the first day. Do as follows:

Power-on the telescope and lower it to 45 degrees using the command alt 45.
If you have not already set tcs.setup-tel-notcam, then do it now.
Open the mirror covers: o-m-c.
Switch on the NOTCam QC lamp from the panel on the wall in the control room. Make sure all other dome-lights are off.
In the NOTCam Sequencer run the setup script notcam.setup-ima wf 201 which sets up the instrument to WF-camera and J-band filter.
Adjust the lamp intensity using the large knob labelled "intensity level" above the lower panel to around 56. Test that exp 4.2 gives around 5000 adu per pixel in the brightest areas.
Close the staircase entrance to make sure nobody enters the dome.
In the NOTCam Sequencer start the QC script (either the first one, or the two readout modes individually) as follows:
- notcam.lintest (both modes, takes about 90 min and produces 168 files)
- notcam.lintest-rrr (r-r-r mode, takes about 60 min and produces 138 files)
- notcam.lintest-rs (r-s mode, takes about 30 min and produces 30 files)
Don't forget to switch off the lamp when finished!
The above sets of data provide readout noise, gain, bad pixels, dark level and non-linearity for each readout mode. To analyse the data, type:
- notcam.lintest-analyse rrr filename1 (for the reset-read-read dataset)
- notcam.lintest-analyse rs filename1 (for the ramp-sampling dataset)
where filename1 is the first file in each dataset. For the rrr dataset this is the first image with OBJECT name "Lintest drk 0s". For the rs dataset, the first file has OBJECT name "mdark 0 5", and if the data is taken in one go with the command notcam.lintest, then this file has a running number of 138 + the above file number.
Check that the NOTCam detector behaviour is OK by looking at the QC result plots on the web pages: Ramp-sampling mode detector monitoring and Reset-read-read mode detector monitoring.

The instrument setup is checked and set in the lintest scripts, but for your reference it is:


Wheel	Position	Content
Aperture	#4	OPEN large
Filter 1	#15	OPEN
Filter 2	#13	J
Stop	#12	15mm ring
Grism	#2	empty
Lens	#1	WF
Camera focus	5650	5650

On the sky

Rotation centre This should be done every time NOTCam is re-mounted on the telescope. Update the table below.

Script: Make sure you have field-r -90 and go to a suitable star (e.g. focus or standard star) high in the sky. Then run the script:

notcam.rotation-centre <exptime>

This takes images for both WF and HR camera. You must manually find the positions of stars (use imexam) and calculate the rotation centre (can be done later). This will be improved in a future version.

Or manually: Use the same setting as for detector monitoring above and point the telescope to a focus star close to zenith. Use first the default sky orientation for NOTCam: field-r -90 and take an exposure with exp 15. If this leads to overexposure, then use a fainter star. Save the image. Then set field-r 90 and take another exposure. Go back to field-r -90 and take a new exposure. This should be sufficient to determine the XY values of the rotation centre on the array and to have an idea of the accuracy. Do the same for the HR camera.


Date	WF X	WF Y	HR X	HR Y	note
5-Sep-2001	451.9	555.4
27 Apr 2004	527	549			Hband, short exposures, daytime
2 Jul 2004	533.8	549.7
21 Jan 2005	529.9	550.8
25 Mar 2005	531.0	543.2
18 May 2005	538.5	546.0			2 stars, 1 measurement
15 Jun 2005	531	546	499	546	1 star, 1 measurement
14 Jan 2006	473.4+-0.1	554.5+-0.07	507.6	562.9	5 stars (WF), new array! X-flip
15 Mar 2006	472.8	550.3	511.0	557.8	2 stars (WF), 1 star (HR) X-flip
11 May 2006	518.1+-0.2	558.7+-0.1			3 stars (WF), old array! X-flip
29 Jan 2007	501.0+-0.1	548.8+-0.1	530.1+-0.4	550.5+-0.04	2 stars, old array! X-flip
24 Feb 2007	501.4+-0.1	551.2+-0.1	-	-	old array! X-flip
29 Apr 2007	500.4+-0.1	552.3+-0.1	523.3+-0.3	554.9+-0.3	old array! X-flip
2 Sep 2007	500.8	556.18	-	-	old array! X-flip
30 Sep 2007	498.0	552.2	508.8	558.5	2 stars, old array! X-flip
16 Nov 2007	501.8	550.4	531.9	551.2	old array! X-flip
13 Dec 2007	502.2	537.8	549.6	549.9	New Science array! X-flip
16 Apr 2008	497.6	536.2	543.9	541.6	New Science array! X-flip
21 May 2008	498.8	533.7	-	-	New Science array! X-flip
11 Jan 2009	501.2	535.5	-	-	New Science array! X-flip
07 Mar 2009	501.8	534.1	-	-	New Science array! X-flip
03 Aug 2009	496.7	533.9	554.4	518.2	New Science array! X-flip
09 Sep 2009	483.7	541.5	511.4	538.1	New Science array! X-flip
15 Oct 2009	483.0	541.5	508.5	540.0	New Science array! X-flip
26 Nov 2009	484.1	540.0	509.7	543.0	New Science array! X-flip
19 May 2010	488.8	540.8	518.9	538.7	New Science array! X-flip
20 Jun 2010	484.2	540.5	-	-	New Science array! X-flip
18 Nov 2010	486.4	541.9	521.5	546.6	New Science array! X-flip
10 Dec 2010	491.0	541.3	529.7	549.0	New Science array! X-flip
12 Feb 2011	495.2	548.8	545.4	585.8	New Science array! X-flip
19 Feb 2011	495.8	544.7	548.1	585.6	New Science array! X-flip
10 Jun 2011	500.2	529.4	551.4	549.8	New Science array! X-flip
13 Aug 2011	496.0	532.9	542.8	554.9	New Science array! X-flip
12 Oct 2011	500.2	531.7	547.8	554.8	New Science array! X-flip
07 Jan 2012	497.7	531.2	554.6	546.4	New Science array! X-flip
01 Apr 2012	500.8	544.5	549.3	573.0	New Science array! X-flip
01 May 2012	500.0	544.0	554.5	564.0	New Science array! X-flip!
09 Jun 2012	488.0	543.9	522.7	569.8	New Science array! X-flip!
01 Oct 2012	491.6	540.8	525.9	561.2	New Science array! X-flip!
17 Feb 2013	499.5	547.8	556.9	576.8	New Science array! X-flip!
22 Mar 2013	501.7	547.0	561.3	572.8	New Science array! X-flip!
25 Apr 2013	498.4	548.9	556.0	577.4	New Science array! X-flip!
22 Jun 2013	499.5	530.6	549.7	573.1	New Science array! X-flip!
29 Aug 2013					New Science array! X-flip!
20 Oct 2013	502.3	548.9	541.1	565.1	New Science array! X-flip!
15 Dec 2013	497.6	540.9	547.5	559.7	New Science array! X-flip!
13 Mar 2014	499.3	541.1	554.7	547.1	New Science array! X-flip!
04 Apr 2014	493.5	540.6	553.6	563.7	New Science array! X-flip!
19 May 2014	496.6	540.0	544.1	557.2	New Science array! X-flip!
9 Jun 2014	495.3	542.1	550.9	559.9	New Science array! X-flip!
8 Aug 2014	497.3	540.0	544.6	548.4	New Science array! X-flip!
3 Sep 2014	502.7	540.2	552.0	557.4	New Science array! X-flip!
5 Oct 2014	501.5	541.5	545.5	557.0	New Science array! X-flip!
29 Oct 2014	499.9	539.2	560.3	565.6	New Science array! X-flip!
7 Nov 2014	506.7	538.3	580.8(?)	539.5(?)	New Science array! X-flip! Script crashed after first HR exp
4 Feb 2015	488.9	541.7	538.6	563.7	New Science array! X-flip!
5 Mar 2015	498.3	539.8	555.0	559.1	New Science array! X-flip!
2 May 2015	493.1	543.5	536.0	563.0	New Science array! X-flip!
29 May 2015	497.7	541.0	552.3	558.8	New Science array! X-flip!
2 Aug 2015	495.8	542.0	537.8	561.5	New Science array! X-flip!
2 Sep 2015	498.2	541.9	538.8	555.5	New Science array! X-flip!
26 Sep 2015	497.6	540.5	541.2	557.0	New Science array! X-flip!
27 Oct 2015	495.1	543.0	535.8	563.1	New Science array! X-flip!
23 Jan 2016	499.6	537.9	559.3	554.3	New Science array! X-flip!
20 Apr 2016	498.4	539.5	550.1	550.9	New Science array! X-flip!
29 Apr 2016	497.5	540.5	537.4	550.1	New Science array! X-flip!
22 May 2016	494.6	539.9	549.3	554.8	New Science array! X-flip!
11 June 2016	498.7	538.3	549.4	550.8	New Science array! X-flip!
14 July 2016	496.4	539.5	541.1	556.0	New Science array! X-flip!
27 July 2016	496.4	538.1	550.5	551.9	New Science array! X-flip!
11 Aug 2016	509.1	527.1	547.1	559.1	New Science array! X-flip!
15 Sept 2016	494.5	539.9	520.3	555.8	New Science array! X-flip!
13 Oct 2016	498.9	537.3	555.9	549.1	New Science array! X-flip!
10 Nov 2016	493.5	542.2	536.8	563.6	New Science array! X-flip!
30 Nov 2016	493.6	539.7	530.2	558.1	New Science array! X-flip!
15 Dec 2016	493.5	538.2	541.5	552.5	New Science array! X-flip!
09 Jan 2017	488.3	540.1	535.8	552.7	New Science array! X-flip!
07 Feb 2017	494.3	535.9	539.8	537.4	New Science array! X-flip!
19 Feb 2017	494.3	535.9	539.8	537.4	New Science array! X-flip!
01 Mar 2017	494.2	539.5	541.2	554.2	New Science array! X-flip!
24 May 2017	496.0	535.8	539.8	545.6	New Science array! X-flip!
20 June 2017	495.7	537.8	528.9	546.9	New Science array! X-flip!
26 Oct 2017	497.6	537.6	535.5	549.1	New Science array! X-flip!
11 May 2018	491.9	537.5	531.5	555.5	New Science array! X-flip!
10 Jun 2018	494.2	541.2	541.5	552.2	New Science array! X-flip!
30 Jun 2018	498.1	538.3	544.2	550.8	New Science array! X-flip!
19 Aug 2018	493.0	540.0	544.0	551.5	New Science array! X-flip!
23 Sep 2018	497.5	541.0	545.6	553.8	New Science array! X-flip!
10 Dec 2018	496.6	540.0	550.0	556.7	New Science array! X-flip!
29 Jan 2019	499.1	540.2	547.5	554.7	New Science array! X-flip!
09 Apr 2019	493.1	541.5	551.2	518.3	New Science array! X-flip!
30 Apr 2019	495.8	538.7	556.2	557.9.3	New Science array! X-flip!
13 Sep 2019	499.3	535.6	--	--	New Science array! X-flip!
16 Nov 2019	502.2	536.5	554	550	New Science array! X-flip!
05 Feb 2020	496.3	539.9	538.6	554.0	2 stars (WF, HR)
03 Mar 2020	493.6	541.5	567.6	560.9	1 star (WF, HR)
09 Sep 2020	496.4	540.3	532.6	555.3	1 star (WF, HR)
30 Oct 2020	494.2	541.7	535.1	559.35	2 stars, poor seeing (WF, HR)
20 Nov 2020	492.5	541.1	527.0	568.3	1 star (WF, HR)

Instrument alignment This should be done every time NOTCam is mounted on the telescope. Update the table below.

Use the same setting as for detector monitoring above and point the telescope to a focus or standard star close to zenith.

In order to determine the alignment, make sure the field orientation is set to field -90, and put the star on position X=200, Y=600. Do this by using the sequencer command slitoff 200 600, where you follow the instructions and iterate once. Make an exp 15 integration, and use imexam (and the 'a' key) to measure the X,Y position of the star. Then move the star to X ~ 800 by using the command teloffset 140 0. Take another exp 15 and move back by teloffset -140 0 to take a third exposure. Now you have the two positions X1,Y1 and X2,Y2 of the star, of which the first one is measured twice such that you have an indication of the error.

The line connecting the two observed positions of the star will make a small angle with the detector rows. This angle can be determined as offset_angle = arctan(dY/dX), where dY = Y2-Y1, and dX = X2-X1. Add this small number to the field-r value (-90) in table below. If it is very different from the previously measured values, the slits must be realigned. (The slits should be aligned to follow this slight tilt.) See instructions on How to align NOTCam slits.


Date	Field angle needed to align RA with X (deg)	Comment
Aug-2003	-90.3	Eng. Grade Array
Jul-2004	-90.5	Eng. Grade Array
Mar-2005	-90.7	Eng. Grade Array
May-2005	-90.8	Eng. Grade Array
Jun-2005	-90.8	Eng. Grade Array
Jan-2006	-90.8	First Science Array (X-flipped image)
Mar-2006	-90.5	First Science Array (X-flipped image)
May-2006	-89.1	Eng. Grade Array back (X-flipped image)
Jan-2007	-89.4	Eng. Grade Array back (X-flipped image)
Feb-2007	-89.2	Eng. Grade Array back (X-flipped image)
Apr-2007	-89.0	Eng. Grade Array back (X-flipped image)
Sep-2007	-89.3	Eng. Grade Array back (X-flipped image)
Dec-2007	-90.1	New Science Array (X-flipped image)
Apr-2008	-90.2	New Science Array (X-flipped image)
May-2008	-90.1	New Science Array (X-flipped image)
Sep-2008	-90.1	New Science Array (X-flipped image)
Jan-2009	-90.1	New Science Array (X-flipped image)
Mar-2009	-90.1	New Science Array (X-flipped image)
Apr-2009	-90.2	New Science Array (X-flipped image)
Aug-2009	-90.2	New Science Array (X-flipped image)
Dec-2010	-90.1	New Science Array (X-flipped image)
Feb-2011	-90.1	New Science Array (X-flipped image)
13 Aug 2011	-90.1	New Science Array (X-flipped image)
12 Oct 2011	-90.1	New Science Array (X-flipped image)
07 Jan 2012	-90.1	New Science Array (X-flipped image)
05 Feb 2012	-90.0	New Science Array (X-flipped image)
01 May 2012	-89.86	New Science Array (X-flipped image)
09 Jun 2012	-90.1	New Science Array (X-flipped image)
19 Feb 2013	-90.1	New Science Array (X-flipped image)
22 Mar 2013	-90.0	New Science Array (X-flipped image)
25 Apr 2013	-90.1	New Science Array (X-flipped image)
20 Oct 2013	-90.2	New Science Array (X-flipped image)
15 Dec 2013	-89.9	New Science Array (X-flipped image)
13 Mar 2014	-90.1	New Science Array (X-flipped image)
04 Apr 2014	-89.9	New Science Array (X-flipped image)
14 Apr 2014	-89.9	New Science Array (X-flipped image)
19 May 2014	-89.9	New Science Array (X-flipped image)
8 Aug 2014	-90.05	New Science Array (X-flipped image)
22 Aug 2014	-89.96	New Science Array (X-flipped image)
3 Sep 2014	-89.88	New Science Array (X-flipped image)
5 Oct 2014	-90.02	New Science Array (X-flipped image)
29 Oct 2014	-90.02	New Science Array (X-flipped image)
5 Mar 2015	-90.00	New Science Array (X-flipped image)
4 Apr 2015	-89.90	New Science Array (X-flipped image)
2 may 2015	-90.0	New Science Array (X-flipped image)
29 May 2015	-90.00	New Science Array (X-flipped image)
3 Jul 2015	-90.00	New Science Array (X-flipped image)
2 Aug 2015	-90.00	New Science Array (X-flipped image)
2 Sep 2015	-90.00	New Science Array (X-flipped image)
26 Sep 2015	-90.06	New Science Array (X-flipped image)
23 Jan 2016	-89.84	New Science Array (X-flipped image)
20 Apr 2016	-90.06	New Science Array (X-flipped image)
29 Apr 2016	-89.96	New Science Array (X-flipped image)
22 May 2016	-89.90	New Science Array (X-flipped image)
11 June 2016	-89.86	New Science Array (X-flipped image)
14 July 2016	-89.96	New Science Array (X-flipped image)
11 Aug 2016	-90.00	New Science Array (X-flipped image)
15 Sept 2016	-90.06	New Science Array (X-flipped image)
13 Oct 2016	-90.02	New Science Array (X-flipped image)
30 Nov 2016	-89.88	New Science Array (X-flipped image)
15 Dec 2016	-89.81	New Science Array (X-flipped image)
09 Jan 2017	-90.04	New Science Array (X-flipped image)
07 Feb 2017	-89.98	New Science Array (X-flipped image)
01 Mar 2017	-89.83	New Science Array (X-flipped image)
24 May 2017	-89.90	New Science Array (X-flipped image)
20 June 2017	-89.91	New Science Array (X-flipped image)
26 May 2018	-89.87	New Science Array (X-flipped image)
10 Jun 2018	-90.08	New Science Array (X-flipped image)
13 Jul 2018	-89.63	New Science Array (X-flipped image)
30 Jul 2018	-89.85	New Science Array (X-flipped image)
19 Aug 2018	-89.87	New Science Array (X-flipped image)
23 Sep 2018	-89.91	New Science Array (X-flipped image)
03 Nov 2018	-89.87	New Science Array (X-flipped image)
10 Dec 2018	-89.96	New Science Array (X-flipped image)
05 Feb 2020	-89.99	New Science Array (X-flipped image)
02 Mar 2020	-90.08	New Science Array (X-flipped image)
09 Sep 2020	-89.83	New Science Array (X-flipped image)
30 Oct 2020	-90.16	New Science Array (X-flipped image)
20 Nov 2020	-88.99	New Science Array (X-flipped image)

Since beginning of 2004 we have attached alignment devices to secure a repeatable position of NOTCam with respect to its blue adapter flange. Thus, the placement of NOTCam with respect to the telescope should be more stable. From the above values the precision seems to be +- 0.1 degrees. The 3 different arrays clearly have a slightly different orientation in the socket.

To check what field-r value is needed to get RA and DEC perfectly aligned along the detector XY, set the rotator to the required field angle (current field angle plus the above derived offset angle) and move the telescope using the TCS ('alt' plus 'arrow' keys one step) having first set o-s 140 140 on the TCS. Do not use teloffset because it will account for the change to the new field angle and the stars will still move tilted wrt the rows of the detector. The correction to the field-r value for perfect alignment could in the future be implemented as a correction to be applied by the TCS to all field values used whenever NOTCam is mounted. This will allow dithering along the slit with a simple teloffset command directly N-S for field -90). Until this is done, if ever, dithering along the slit must be accounted for by tilting the slit so that it is aligned exactly N-S, i.e. about 0.1-0.2 degrees offset from -90.0 degrees for the new Science Array.

If the rotational offset that you have determined is different from the previous determination (see table above), then the slits have to be realigned! See instructions.

Comments to Amanda

Last modified: 21-Nov-2020