LBA Experiment V230

Goal: to determine position of stations ATCA, MOPRA, CEDUNA with accuracy 1-10 cm. Text of the proposal.

Preliminary results

Preliminary results on 05-FEB-2008 11:55:03 using RR and LL data. Formal errors for site positions are: ± 10 — 30 mm for the vertical component and ± 3 — 6 mm for horizontal components. Plot of residuals at all baselines and plot of a sum of residuals and estimates of clock function at all baselines. The overall fit at all baselines is 50.1 ps with 2.5% observations discarded at RR polarization and 40.0 ps at LL polarization (with 7% of points discarded). 80% of scheduled observations at RR polarization and 90% of observations at LL polarization were used in the solution.

Listings of RR solution and LL solution are here. 

Epoch  1997.01.01
   39. ATCA-104 7373 AUST  X Comp      -4751639826.83 mm          0.172 mm             22.651 mm             22.651 mm    global
   40. ATCA-104 7373 AUST  Y Comp       2791700371.51 mm          0.506 mm             28.893 mm             28.893 mm    global
   41. ATCA-104 7373 AUST  Z Comp      -3200491152.11 mm         -0.108 mm             28.086 mm             28.086 mm    global

 Minimum sigma:   3. ATCA-104 7373       (Epoch = 070624):
       ATCA-104 7373       X Comp      -4751640182.47 mm       -355.469 mm              8.478 mm              0.000 mm    global
       ATCA-104 7373       Y Comp       2791700321.68 mm        -49.321 mm              5.969 mm              0.000 mm    global
       ATCA-104 7373       Z Comp      -3200490667.73 mm        484.268 mm              7.232 mm              0.000 mm    global
       ATCA-104 7373       U Comp               -1.40 mm         -1.405 mm             11.639 mm              0.000 mm    global
       ATCA-104 7373       E Comp              222.59 mm        222.592 mm              3.501 mm              0.000 mm    global
       ATCA-104 7373       N Comp              560.14 mm        560.140 mm              3.476 mm              0.000 mm    global

Epoch  1997.01.01
  130. CEDUNA   7371 AUST  X Comp      -3753442731.11 mm         -0.107 mm             30.643 mm             30.643 mm    global
  131. CEDUNA   7371 AUST  Y Comp       3912709766.50 mm         -0.504 mm             30.215 mm             30.215 mm    global
  132. CEDUNA   7371 AUST  Z Comp      -3348067582.44 mm         -0.443 mm             31.449 mm             31.449 mm    global

 Minimum sigma:  14. CEDUNA   7371       (Epoch = 070624):
       CEDUNA   7371       X Comp      -3753443168.29 mm       -437.290 mm             17.095 mm              0.000 mm    global
       CEDUNA   7371       Y Comp       3912709794.49 mm         27.495 mm             17.196 mm              0.000 mm    global
       CEDUNA   7371       Z Comp      -3348067059.64 mm        522.364 mm             16.618 mm              0.000 mm    global
       CEDUNA   7371       U Comp               -1.84 mm         -1.844 mm             28.080 mm              0.000 mm    global
       CEDUNA   7371       E Comp              296.53 mm        296.533 mm              6.358 mm              0.000 mm    global
       CEDUNA   7371       N Comp              613.93 mm        613.928 mm              5.928 mm              0.000 mm    global

Epoch  1997.01.01
 1244. MOPRA    7372 AUST  X Comp      -4682769083.19 mm         -0.192 mm             23.170 mm             23.170 mm    global
 1245. MOPRA    7372 AUST  Y Comp       2802619000.54 mm         -0.461 mm             28.933 mm             28.933 mm    global
 1246. MOPRA    7372 AUST  Z Comp      -3291759345.12 mm         -0.116 mm             27.936 mm             27.936 mm    global

 Minimum sigma:  86. MOPRA    7372       (Epoch = 070624):
       MOPRA    7372       X Comp      -4682769444.29 mm       -361.286 mm              8.931 mm              0.000 mm    global
       MOPRA    7372       Y Comp       2802618962.77 mm        -38.233 mm              6.270 mm              0.000 mm    global
       MOPRA    7372       Z Comp      -3291758863.51 mm        481.485 mm              7.638 mm              0.000 mm    global
       MOPRA    7372       U Comp               -1.71 mm         -1.715 mm             12.272 mm              0.000 mm    global
       MOPRA    7372       E Comp              218.34 mm        218.344 mm              3.726 mm              0.000 mm    global
       MOPRA    7372       N Comp              562.26 mm        562.263 mm              3.596 mm              0.000 mm    global

Apriori velocites in mm/yr

                        X               Y               Z

    ATCA-104          -33.94           -4.75           46.23    NNR-NUVEL1A
    CEDUNA            -41.73            2.67           49.90    NNR-NUVEL1A
    MOPRA             -34.47           -3.61           45.97    NNR-NUVEL1A
In order to test a feasibility of extention of the Calibrator Survey to the southern hemisphere, 5 new sources, perviosly not observed with VLBI, were included into the schedule, two scans per source.
All 5 new sources have been detected. Formal errors of their position are ± 2 — 6 mas. 
SOU_GCO:  0100-760  R:  01_02_18.66097850 -+    26.4919  D:  -75_46_51.7302278 -+     3.1194  C:  -0.445 Obs_used:      24 Obs_tot:      32 Ses_used:     2 Ses_tot:     2 Date_beg: 2007.06.24 Date_end: 2007.06.24
SOU_GCO:  0219-637  R:  02_20_54.17215970 -+     6.4408  D:  -63_30_19.3873554 -+     1.7726  C:  -0.225 Obs_used:      31 Obs_tot:      32 Ses_used:     2 Ses_tot:     2 Date_beg: 2007.06.24 Date_end: 2007.06.24
SOU_GCO:  0333-729  R:  03_32_43.00085043 -+    17.0217  D:  -72_49_04.5210792 -+     3.5898  C:  -0.312 Obs_used:      18 Obs_tot:      32 Ses_used:     2 Ses_tot:     2 Date_beg: 2007.06.24 Date_end: 2007.06.24
SOU_GCO:  1941-554  R:  19_45_24.24767437 -+    10.5545  D:  -55_20_48.9484777 -+     5.7066  C:  -0.097 Obs_used:       5 Obs_tot:      16 Ses_used:     2 Ses_tot:     2 Date_beg: 2007.06.24 Date_end: 2007.06.24
SOU_GCO:  2140-781  R:  21_46_30.06936834 -+     4.1088  D:  -77_55_54.7353692 -+     2.4210  C:   0.779 Obs_used:      25 Obs_tot:      25 Ses_used:     2 Ses_tot:     2 Date_beg: 2007.06.24 Date_end: 2007.06.24

Schedule file and log files

Problems

Group delays at PARKES show a scatter at a level ± 2 ns. Refer to the plot of residuals with clock function.

Estimates of clock function at baseline HOBART26/PARKES at v230 experiment have a scatter ± 2000 ps, while normally they should have a scatter one order of magnitude less: of ± 100 — 300 ps. For example, the estimate of clock function at baseline HOBART26/PARKES at crf45 experiment that run two weeks earlier on 2007.06.12 were a smooth function of time with peak to peak variations 200 ps.

Analysis of short time variabilities of fringes amplitudes and fringe phase at baselines with Parkes did not reveal anything unusual:

The scatter of fringe phases within 2 minutes is not much greater at baselines with PARKES than at baselines without PARKES. The clock behavior is consistent with lack of phase stability at some parts of equipment. It is unlikely it is caused by malfunctioning of H-maser itself, since estimates of clock function have very small scatter at IVS experiments before and after v230.

Schedule of the v230 experiment in sked format.

Schedule of the v230 experiment in vex format.

Listing of the coarse solutions using v230 data.

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This page was prepared by Leonid Petrov ()
Last update: 2008.04.30_16:47:38