LOFAR Transients Pipeline (“TraP”)

LOFAR Transients Pipeline (“TraP”)

From the webpage:

The LOFAR Transients Pipeline (“TraP”) provides a means of searching a stream of N-dimensional (two spatial, frequency, polarization) image “cubes” for transient astronomical sources. The pipeline is developed specifically to address data produced by the LOFAR Transients Key Science Project, but may also be applicable to other instruments or use cases.

The TraP codebase provides the pipeline definition itself, as well as a number of supporting routines for source finding, measurement, characterization, and so on. Some of these routines are also available as stand-alone tools.

High-level overview

The TraP consists of a tightly-coupled combination of a “pipeline definition” – effectively a Python script that marshals the flow of data through the system – with a library of analysis routines written in Python and a database, which not only contains results but also performs a key role in data processing.

Broadly speaking, as images are ingested by the TraP, a Python-based source-finding routine scans them, identifying and measuring all point-like sources. Those sources are ingested by the database, which associates them with previous measurements (both from earlier images processed by the TraP and from other catalogues) to form a lightcurve. Measurements are then performed at the locations of sources which were expected to be seen in this image but which were not detected. A series of statistical analyses are performed on the lightcurves constructed in this way, enabling the quick and easy identification of potential transients. This process results in two key data products: an archival database containing the lightcurves of all point-sources included in the dataset being processed, and community alerts of all transients which have been identified.

Exploiting the results of the TraP involves understanding and analysing the resulting lightcurve database. The TraP itself provides no tools directly aimed at this. Instead, the Transients Key Science Project has developed the Banana web interface to the database, which is maintained separately from the TraP. The database may also be interrogated by end-user developed tools using SQL.

While it uses the term “association,” I think you will conclude it is much closer to merging in a topic map sense:

The association procedure knits together (“associates”) the measurements in extractedsource which are believed to originate from a single astronomical source. Each such source is given an entry in the runningcatalog table which ties together all of the measurements by means of the assocxtrsource table. Thus, an entry in runningcatalog can be thought of as a reference to the lightcurve of a particular source.

Perhaps not of immediate use but good reading and a diversion from corruption, favoritism, oppression and other usual functions of government.

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