diff --git a/CEP/Pipeline/recipes/sip/bin/msss_imager_pipeline.py b/CEP/Pipeline/recipes/sip/bin/msss_imager_pipeline.py index 954745b1416a0223ac766155bea79c1edd2ce420..76ac9b4d94c8bb538f527dbc6da9938a9ab4eb7f 100755 --- a/CEP/Pipeline/recipes/sip/bin/msss_imager_pipeline.py +++ b/CEP/Pipeline/recipes/sip/bin/msss_imager_pipeline.py @@ -20,43 +20,70 @@ from lofarpipe.support.utilities import patch_parset class msss_imager_pipeline(control): - """ - The MSSS imager pipeline can be used to generate MSSS images. - - MSSS images are compiled from a number of so-called slices. Each slice + """ + The Automatic MSSS imager pipeline is used to generate MSSS images and find + sources in the generated images. Generated images and lists of found sources + are complemented with meta data and thus ready for consumption by the + Long Term Storage (LTA) + + *subband groups* + The imager_pipeline is able to generate images on the frequency range of + LOFAR in parallel. Combining the frequency subbands together in so called + subbandgroups. Each subband group will result in an image and sourcelist, + (typically 8, because ten subband groups are combined). + + *Time Slices* + MSSS images are compiled from a number of so-called (time) slices. Each slice comprises a short (approx. 10 min) observation of a field (an area on the - sky) containing 80 subbands. The number of slices will be different for LBA - observations (typically 9) and HBA observations (typically 2), due to - differences in sensitivity. - - One MSSS observation will produce a number of images (typically 8), one for - each so-called subband-group (SBG). Each SBG consists of the same number - of consecutive subbands (typically 10). + sky) containing typically 80 subbands. The number of slices will be + different for LBA observations (typically 9) and HBA observations + (typically 2), due to differences in sensitivity. Each image will be compiled on a different cluster node to balance the processing load. The input- and output- files and locations are determined by the scheduler and specified in the parset-file. + + *steps* + This pipeline performs the following operations: + + 1. Prepare Phase: Copy the preprocessed MS's from the different compute + nodes to the nodes where the images will be compiled (the prepare phase). + Combine the subbands in subband groups, concattenate the timeslice in a + single large measurement set and perform flagging, RFI and bad station + exclusion. + 2. Create db: Generate a local sky model (LSM) from the global sky model + (GSM) for the sources that are in the field-of-view (FoV). The LSM + is stored as sourcedb. + In step 3 calibration of the measurement sets is performed on these + sources and in step 4 to create a mask for the awimager. The calibration + solution will be placed in an instrument table/db also created in this + step. + 3. BBS: Calibrate the measurement set with the sourcedb from the gsm. + In later iterations sourced found in the created images will be added + to this list. Resulting in a selfcalibration cycle. + 4. Awimager: The combined measurement sets are now imaged. The imaging + is performed using a mask: The sources in the sourcedb are used to create + an casa image masking known sources. Together with the measurement set + an image is created. + 5. Sourcefinding: The images created in step 4 are fed to pyBDSM to find and + describe sources. In multiple itterations substracting the found sources, + all sources are collectedin a sourcelist. + I. The sources found in step 5 are fed back into step 2. This allows the + Measurement sets to be calibrated with sources currently found in the + image. This loop will continue until convergence (3 times for the time + being). + 6. Finalize: Meta data with regards to the input, computations performed and + results are collected an added to the casa image. The images created are + converted from casa to HDF5 and copied to the correct output location. + 7. Export meta data: An outputfile with meta data is generated ready for + consumption by the LTA and/or the LOFAR framework + + Per subband-group, the following output products will be delivered: + a. An image + b. A source list + c. (Calibration solutions and corrected visibilities) - This pipeline will perform the following operations: - - Copy the preprocessed MS's from the different compute nodes to the nodes - where the images will be compiled (the prepare phase). - - Flag the long baselines using DPPP - - Concatenate the MS's of the different slices as one virtual MS for - imaging. - - Generate a local sky model (LSM) from the global sky model (GSM) for the - sources that are in the field-of-view (FoV). - - Repeat until convergence (3 times for the time being): - - Per slice: solve and correct for phases using BBS with TEC enabled - - Run the awimager. - - Run the source finder (PyBDSM) and update the local sky model (LSM). - - Per subband-group, the following output products will be delivered: - - Calibration solutions and corrected visibilities - - An image - - A source list """ - - def __init__(self): control.__init__(self) self.parset = parameterset()