02 June 2012 (until 05:00 UT)

Summary:

We spent some time testing binorb in the hope of collecting data for a binocular range-balanced Gregorian collimation model.

  • First task: copoint on both sides. We were using AGws on LBBG and RFBG and the collimation models were, respectively, SX_LBBG.20111211.ptmod and RFBG_AGw.20111208.ptmod. CA and IE values which achieved co-pointing were:
PM left right
CA -15 -147.8
IE -47 -49.5

  • Once co-pointed and guiding/collimating, the LBTtools task binorb in Sandbox was run. While this script has many inputs and modes, the last days we focused on getting it to work when guiding on both left and right sides. The script reads the current positions of M1 and M2, uses the binocular range-balancing algorithm of A Rakich (481s066) to correct pointing (mode 1) while optimizing the range available to M1 and M2 on both sides. The description below is taken from the script:

 #   binorb reads:                                                            #
 #         * current positions for SXM1/SXM2 and DXM1/DXM2 from headers       #
 #            or, for AGws, from telescope data dictionary (DD)               #
 #         * current pointing offsets, CE and CA, from telescope              #
 #         * temperatures: M1glass, M1ambient, collimation T1, and T2 from DD #
 #                                                                            #
 #   binorb then does binocular RB following algorithm of A Rakich(481s066)   #
 #         * starting with SXM1,SXM2,DXM1,DXM2 positions which correspond to  #
 #           individually collimated SX or DX telescope, determines offsets   #
 #           to these positions, and to the pointing model CA and CE, which   #
 #           effect a "mode 1" pointing correction of each component          #
 #           telescope, such that both sides co-point while maximizing the    #
 #           available range of motion to each mirror.                        #
 #                                                                            #
 #   OUTPUT: the range balanced positions for SXM1/SXM2 and DXM1/DXM2         #
 #          as:                                                               #
 #             * delta mirror position:                                       #
 #             * delta CA and delta IE                                        #
 #             * absolute mirror position                                     #
 #             * telescope elevation and temperatures                         #

The output file currently has many column which are:
Original M1 position Original M2 position Original pointing offsets M1 Original pointing offsets M2 Temperatures Elevation code RB M1 position RB M2 position RB pointing offsets M1 RB pointing offsets M2 Temperatures Elevation code
X Y Z RX RY RZ x y z rx ry rz PNTX PNTY PNTRX PNTRY pntx pnty pntrx pntry M1glass M1ambient T1coll T2coll elev -1 X Y Z RX RY RZ x y z rx ry rz PNTX PNTY PNTRX PNTRY pntx pnty pntrx pntry M1glass M1ambient T1coll T2coll elev -1

There are repetitions and unecessary information for the range-balanced collimation model, (e.g. Z, RZ,z,rz which are not changed in range-balancing), but for the start, I erred on printing too much information... These outputs go to the root filename defined in binorb _dd_{sx,dx}.txt to which one line is added for every run of binorb.

The binorb parameter file looked like:
                         Image Reduction and Analysis Facility
PACKAGE = Sandbox
   TASK = binorb

SXcamera=                  agw  Camera on SX (LBC,IRTC,LUCI,MODS,AGW)
SXfocals=                 LBBG  SX focal station (prime,LDG,LFBG,LCBG,LBBG) 
SXtimest=                   -1  Timestamp of SX image to process (-1 if active on-axis preset & AGW)
DXcamera=                  agw  Camera on DX (LBC,IRTC,PISCES,AGw)
DXfocals=                 rfbg  DX focal station (prime,RDG,RFBG,RCBG,RBBG) 
DXtimest=                   -1  Timestamp of DX image to process (-1 if active on-axis preset & AGW)
(modscha=                    b) If MODS, which channel (b or r)?
(outfile=           jun2coll2_) root name of output file for collimation models
(sendtel=                  yes) Send commands to Telescope?
(test   =                   no) Test mode (use internal #s)
(verbose=                  yes) Verbose output to screen?
(mode   =                    h)

and IRTC was authorized on both sides. Instrument AGW was needed to use the mode where no images were sought and telescope data dictionary values read (the "-1" timestamp indicates this). In this case, the instrument to give is AGW and binorb fudges this to IRTC.

Unfortunately, we did not collect any collimation data because the commands to register the left side (thus pause guiding and move the mirrors) failed with:
Invalid proxy: Invalid side, focal station, instrument, or instrument/focal station combination.
Exit 1
This failed for the left side on BOTH invocations, and worked for the right on BOTH. These worked on the right side and the same syntax is there for the left and right, so it's not obvious what to change... this can be tested in day time.

The good news is that for the right side it worked, and we saw guiding pause, the star offset a few arcseconds, but still in the guide window, and guiding resume.

-- OlgaKuhn - 02 Jun 2012
Topic revision: r2 - 02 Jun 2012, OlgaKuhn
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