First X/S VLBI experiment at station WARK12M

On 2011.02.14 VLBI antenna WARK12M located near Auckland, New Zealand participated in VLBI experiment r1470. This was the second experiment the station observed using X/S (8 GHz and 2.3 GHz) receivers. On 2010.05.07 station participated in L-band geodesy experiment. Station position in that experiment were derived with a decimeter level of accuracy.

On 2011.02.24 experiment has been correlated in Bonn using DiFX software correlator. Experiment can be considered as partially successful. Fringes were detected at X and S-bands. However, the scheduled was extremely unfavorable for position determination of WARK12M. Station WARK12M was schedule in a tag-alone mode. That means the schedule was prepared for the network without WARK12M, and then WARK12M was added to observations of those sources which were above the horizon. Since the closest station of the network was in 6.7 thousands km from New Zealand, very few sources had a common visibility zone. Of 39 observations scheduled fringes were detected at 22 observations.

The listing of the solution is accessible here. Results of position determination from r1470:

                                 Total                Adjustment to apriori   Formal error

WARK12M  9999 AUST  X Comp      -5115325325.29 mm        572.708 mm            941.765 mm
WARK12M  9999 AUST  Y Comp        477843761.25 mm        789.246 mm            227.851 mm
WARK12M  9999 AUST  Z Comp      -3767193677.16 mm        923.841 mm            969.263 mm
WARK12M  9999       U Comp             -948.38 mm       -948.383 mm           1335.313 mm
WARK12M  9999       E Comp             -839.09 mm       -839.092 mm            146.498 mm
WARK12M  9999       N Comp              448.20 mm        448.196 mm            271.632 mm
The formal uncertainties are a factor of 2—5 greater than in the L-band astrometry experiment, although the systematic errors are presumably less.

Problems

No signal was found S-band lost two IFs: IF5, and IF6. (Comment from Tim Natush: there was an error in frequency setup, will be fixed in next experiment.) The fringes are detected in IF1 at S-band. These three IFs were removed from fringe fitting. The maximal SNR at X-band 46.4 and at S-band 26.2, which makes difficult to make analysis in depth. No other abnormalities were found. Autocorrelation at X-band shows a strange patter at IF8. Amplitude analysis will be done later.

Fringes plots Fringe phase in radians is shown in green color; fringe amplitude is shown in blue color.

S-band

X-band

S-band autocorrelation

X-band autocorrelation

Zoom of first two IFs:

Zoom of the last IFs:

References

L. Petrov, C. Phillips, T. Tzioumis, B. Stansby, C. Reynolds, H. E. Bignall, S. Gulyaev, T. Natusch, N. Palmer, D. Collett, J. E. Reynolds, S. W. Amy, R. Wayth, S. J. Tingay, First geodetic observations using new VLBI stations ASKAP-29 and WARK12M, accepted by Publ. Astronom. Soc. Australia, 2010, http://arxiv.org/abs/1012.4243
Back to Leonid Petrov's discussion page.

Last update: 2011.02.25_00:31:21