Changes between Version 67 and Version 68 of NightOperations/Commissioning/pFPA

Timestamp:

Oct 15, 2023 10:03:14 AM (7 months ago)

Author:

stevenj

Comment:

--

NightOperations/Commissioning/pFPA

@@ -227 +227 @@
   * Plate-solve the ACQ camera images (use [[http://astrometry.net]] or your own method)
   * Using the WCS-solved ACQ image(s), check which pixel the IHMP coordinates (RA, Dec from Remedy) lands on. In {{{shuffle.cfg}}} the **acam_x_origin** and **acam_y_origin** values should match that pixel.
-  * Remedy also produces the rotation angle. 
+  * Remedy also produces the rotation angle. To compare that with the plate-solved ACQ camera images, check the FITS header keyword {{{CROTA2}}}. The difference between the Remedy-produced VIRUS rotation angle and the ACQ camera rotation angle is the "acam" angle in shuffle.cfg (I think.)
+
+This information from Matthew may help explain the two angles in shuffle.cfg: acam and fplane:
+{{{
+The acam angle sets the ACAM to match the stars.    So I change the ACAM
+and IHMPX, and IHMPY until I match the stars for a setup like LRS2-B
+
+The fplane angle sets the IHMP to match the ACAM pixel locations for
+different requested setup.  If I setup ACAM to match LRS2-B in the first
+step then I simply ask for that star to be on the LRS2-R and look at the
+fake acam image and see if the star is on the LRS2-R position (according
+to the fake acam image).     It will not be unless the fplane angle is
+set correctly.
+
+I iterate these two solutions until I get a match.   It is a unique
+solution (within the errors).
+}}}
+
   * If necessary, update acm origin and angles in fplane file
+  * Ultimately, you can test this by running shuffle to observe a star with LRS2-B and making sure it lands in the IFU. Iterating/adjusting may be necessary.