射电干涉数据自动化处理管线程序SAND与VLBI监测数据挖掘

我们实现了一套致力于射电干涉度数据成图与分析的自动化VLBI数据处理管线程序-SAND。它可以高效地应对海量VLBI观测数据，是挖掘多历元多波段VLBI观测数据的合适工具。与传统手动数据处理相比，我们的管线程序由于涉及更少的人工干预，其处理的结果也相对更加客观。源的提取在像平面，而反卷积和模型拟合同时在像平面和uv平面上进行以便于平行比对。我们的管线程序的输出包括编目的洁图和重建模型、偏振图、本动估计、核心光变曲线以及多波段能谱等。我们还发展一种回归STRIP算法可以自动的甄别线性和非线性的本动轨迹模式。这个算法提供了一个客观的方法来对应不同历元喷流分量并测定其本动。对于多波段数据，我们有后处理程序来进行不同波段光变曲线的交叉相关以及估算不同时段的能谱指数。我们计划使用我们的管线程序对从不同VLBI监测项目中获得的现有四个波段的数据进行处理和分析，以得到对当前类星体吸积盘-黑洞模型的观测量约束。同时，我们在数据处理实践的过程中进一步改进我们管线程序中相应的算法，并通过国际合作扩展其应用到e-MERLIN和LOFAR等较短基线的实时相关干涉阵列。.

We present our implementation of an automated VLBI data reduction pipeline – SAND, which is dedicated to interferometric data imaging and analysis. The pipeline can handle massive VLBI data efficiently which makes it an appropriate tool to investigate multi-epoch multiband VLBI data. Compared to traditional manual data reduction, our pipeline provides more objective results since less human interference is involved. Source extraction is done in the image plane, while deconvolution and model fitting are done in both the image plane and the uv plane for parallel comparison. The output from the pipeline includes catalogues of CLEANed images and reconstructed models, polarization maps, proper motion estimates, core light curves and multiband spectra. We have developed a regression STRIP algorithm to automatically detect linear or non-linear patterns in the jet component trajectories. This algorithm offers an objective method to match jet components at different epochs and determine their proper motions. For multiband data sets, we have made a post-processor to cross-correlate the light curves of different bands and evaluate the spectral indices for different time slots. We plan to reduce and analyse the 4-band data currently collected from several VLBI monitoring programmes with our pipeline, to obtain the observable constraints on current accretion disk - jet model of QSOs. Meanwhile, we are going to improve the relevant algorithms in our pipeline through data reduction practices, and extend its application to interferometric arrays with shorter baselines and real-time correlation, like e-MERLIN and LOFAR, through international collaborations..