This report covers differential pointing between RxWD and RxA from January 2009 to date. The differential pointing performance is measured by pointings with RxA and RxWD consecutively for direct comparison. (All WD observations are taken with channel A unless specified otherwise).

   UT Date    No.    Source    FE       AZ      EL     UAZ     UEL      DAZ     DEL      WD-A
 ----------  ----  ---------  ----     ----    ----   -----   -----    -----   -----   --------
                       
   20090107    3     Uranus    A        227     55     -0.8    7.2   
       "       5        "      WD       232     53      3.1    3.3      3.9     -3.9     5 - 3
       "      19      W3(OH)   WD       359     48      3.8   -3.7      1.0     -4.5    19 - 20
       "      20        "      A        359     48      2.8    0.8
       "      56     IRC10216  A	128	80	1.5   -1.2
       "      59        "      WD	145	82	5.1   -5.3	3.6	-4.1	59 - 56
       "      59        "      WD	145	82	5.1   -5.3	3.7	-4.5	59 - 60
       "      60        "      A	158	83	1.4   -0.8			
       "      64       	"      WDB	183	83	9.8   -6.2	8.4	-5.4	64 - 60
       "      64    	"      WDB	183	83	9.8   -6.2	8.4	-7.8	64 - 65
       "      65    	"      A	193	83	1.4    1.6


   20090112   27     IRC10216  A	84	27     -3.0	5.1			
       "      29        "      WD	86	33	0.6	0.1	3.6	-5.0	29 - 27
       "      29	"      WD	86	33	0.6	0.1	2.7	-6.2	29 - 35
       "      35	"      A	91	46     -2.1	6.3			
       "      		       						
       "      52	"      A	140	81	0.8	2.2			
       "      54	"      WD	162	83	6.3    -3.9	5.5	-6.1	54 - 52
       "      54	"      WD	162	83	6.3    -3.9	6.0	 0.3	54 - 56
       "      56	"      A	189	83	0.1	3.6			
       "      57	"      WD	200	83	5.3    -1.2	5.2	-4.8	57 - 56
       "      57	"      WD	200	83	5.3    -1.2	6.0	-4.7	57 - 59
       "      59	"      A	224	81     -0.7	3.5			
       "      		       						
       "      65	"      A	255	69	0.3	4.3			
       "      66	"      WD	256	67	3.6    -2.2	3.3	-6.5	66 - 65
       "      66	"      WD	256	67	3.6    -2.2	2.5	-6.4	66 - 67
       "      67	"      A	257	66	1.1	4.2			
       "      68	"      WD	259	65	4.2    -1.6	3.1	-5.8	68 - 67
       "      72	"      WD	262	59	4.3	0.6	3.2	-3.6	68 - 72
       "      		       						
       "      80	"      A	270	40	0.1	7.9			
       "      83	"      WD	272	35     -2.8	1.1    -2.9	-6.8	83 - 80

   20090130   32     IRC10216  WD	134	81      3.6    -2.5	4.4	-4.9	32 - 34 	
       "      34        "      A	153	82     -0.8	2.4  
       "      38        "      A        190     83     -0.5     4.4 
       "      39        "      WD       202     83      2.6     1.1     3.1     -3.3    39 - 38     
       "      39        "      WD       202     83      2.6     1.1     4.0     -5.3    39 - 40   
       "      40        "      A        214     82     -1.4     6.4
       "      78        "      A        273     31      1.4     6.7
       "      79        "      WD       274     29      2.1     1.9     0.7     -4.8    79 - 78
       "      80        "      WD       274     28      0.8     1.1     2.2     -4.5    80 - 82
       "      82        "      A        275     26     -1.4     5.6   
       "      83        "      WD       276     24      1.0     1.1     2.5     -4.5    83 - 82

   20090301	    IRC+10216  WD	238	78	5.5    -1.1	3.63	-4.74	
      "	                "      A	248	74	1.9	3.6		
			       							
   20090302	    IRC+10216  A	86	31	1.5    -1.9			
      "		        "      WD	87	35	2.6    -4.9	1.18	-3.04	
			       							
   20090311	    IRC+10216  A	197	83	2.8    -0.5			
      "		        "      WD	233	79	5.5    -5.1	2.69	-4.51	
			       							
   20090314         IRC+10216  WD	267	49     -0.1    -1.8	1.47	-5.48	
      "		        "      A	268	48     -1.5	3.7			
			       							
   20090502         IRC+10216  WD	267	50	12.7   -1.1	10.84	-2.19	
      "		        "      A	267	49	1.9	1.1			
			       							
   20090503         IRC+10216  WD	251	72	13.9   -0.7	12.2	-1.98	
      "		        "      A	254	69	1.7	1.3			
			       							
   20090604	      W75N     WD	40	56	13.5   -4.4	12.42	-8.1	
      "		        "      A	39	57	1.1	3.7			
			       										
   20090605          SATURN    WD	253	57	10.6   -0.3	10.34	-0.29	
      "		        "      A	254	55	0.3	0.0			
			       										
   20090606           G34.3    WD	112	49	14.9   -2.9	14.08	-0.7	
      "		        "      A	115	52	0.8    -2.2			

(UZ and UEL are offsets from the model, whilst DAZ and DEL are offsets from the nearest RxA pointing.)
 

The dramatically different values of DAZ and DEL seen in later dates are the result of engineering work on RxW

The results are displayed below; azimuth on the left and elevation on the right. Where there are 2 possible solutions for daz and del for a single observation, the pairing closet in time was selected. The values derived from channel B have not been included due to the misalignment of the 2 channels on 20090107.

[Note: so far these plots only contain data from the first 3 dates listed.]

The single errant point in daz comes from obs. number #83 on 20090112 which is the sole point with a negative value for daz. Inspection of this observation reveals a tenuous pointing fit and as such it can be considered erroneous and is not included in the fitting below.

These plots demonstrate the absence of either azimuth or elevation dependence in the differential pointing of RxWD.