Bigradient Phase Referencing
Bigradient Phase Referencing
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DOI：
10.1093/pasj/58.4.777
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发表时间：
2006-04
影响因子：
2.3
通讯作者：
A. Doi;K. Fujisawa;A. Habe;M. Honma;N. Kawaguchi;H. Kobayashi;Y. Murata;T. Omodaká;H. Sudou
中科院分区：
文献类型：
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作者：
A. Doi;K. Fujisawa;A. Habe;M. Honma;N. Kawaguchi;H. Kobayashi;Y. Murata;T. Omodaká;H. Sudou
我们提出了双梯度相位参考（BPR），一种新的无线电观测技术，并报告其性能使用日本甚长基线干涉测量网络（JVN）。在该方法中，使用初级校准器通过相位参考来检测弱源，以便作为次级校准器对弱目标进行相位参考。我们将有机会从许多毫扬斯基源中选择一个校准器，其中一个可能位于更接近目标的位置。通过这种较小的间隔，可以实现高质量的相位参考。随后更复杂的校准可以将阵列的焦点重新定位到更接近目标的假设点;可以获得更高质量的相位参考。强射电源的示范观测证明了BPR在图像动态范围和天体测量再现性方面的能力。目标上的图像动态范围与正常相位参考相比提高了约6倍;两个历元之间目标发射的最终位置差仅为62 ±50微弧秒，即使在8.4GHz的基线小于2300公里，并且在目标校准器对之间快速切换，间隔为2。2001年。
We propose bigradient phase referencing (BPR), a new radio-observation technique, and report on its performance using the Japanese very-long-baseline-interferometry network (JVN). In this method, a weak source is detected by phase-referencing using a primary calibrator, in order to play a role as a secondary calibrator for phasereferencing to a weak target. We will be given the opportunity to select a calibrator from lots of milli-Jansky sources, one of which may be located at a position closer to the target. With such a smaller separation, high-quality phase-referencing can be achieved. A subsequent more-sophisticated calibration can relocate the array’s focus to a hypothetical point much closer to the target; a higher quality of phase referencing is available. Our demonstrative observations with strong radio sources have proved the capabilities of the BPR in terms of the image dynamic ranges and astrometric reproducibility. The image dynamic range on a target has been improved by a factor of about six compared to that of normal phase-referencing; the resultant position difference of the target’s emission between two epochs was only 62 ±50 microarcsecond, even with less than 2300-km baselines at 8.4GHz and fast-switching between a target–calibrator pair separated by a 2. ◦ 1.