LOFAR Newsletters October 2015

Distributed on 27 October 2015


Array status:


- 38 stations operational in the Netherlands: 24 core stations and 14 remote stations.

- 9 international stations operational: DE601, DE602, DE603, DE604, DE605, FR606, SE607, UK608, DE609.

- 3 new international stations are being built in Poland and should become part of the array by the end of 2015.

- After the replacement of the LCU, CS013 is being included again in test and production runs.

- The rubidium clock of SE607 and DE602 has been replaced.

- Various Dutch stations were switched off during the warmest summer days because the temperatures within the cabinets reached critical levels. The Cycle 5 observing schedule has been adapted accordingly.

- Maintenance was performed at various stations throughout the summer and is still in progress.

- The overview of non-operational antenna elements for LBA and HBA is available here.

- Station calibration: on September 21st, new mode 3 tables were installed for the Dutch array. On DE609 and RS407, tables for modes 5 and 7 were installed, too. New mode 3 tables are ready for international stations and modes 5 and 7 for all stations. These will be installed as soon as the telescope schedule allows. The reduction of data for new mode 1 tables for the Dutch array is in progress. The station calibration status is shown here.


Observing System Status:


- The observing system was mostly stable during the period August - October 2015. However, failures of COBALT nodes, as well as issues with the central NFS server lcs015, warm temperatures, and the instability of processing and ingest systems caused delays in the exploitation of the Cycle 3&4 observing programmes and in digesting data out of CEP2.

- Low(er) ingest speeds towards the Juelich LTA location are still experienced during ILT runs involving the German stations - investigations are still in progress to try to fix this issue.


Software Development Status (H. Holties):


On September 7th, LOFAR software release 2.12 has been rolled out on the CEP systems which included enabling 160 MHz mode for further commissioning, enabling 4-bit mode processing in Cobalt, and a major refactoring of the ingest software to improve robustness and prepare for future improvements in monitoring and control capabilities. At the moment, the LOFAR software team is preparing for the CEP4 processing cluster which is in the process of being delivered. CEP4 will bring some major changes in the central computational infrastructure, most notably the introduction of a job scheduler for processing pipelines and a cluster file system, which will impact the pipeline framework, (obervation) data writers as well as LOFAR scheduling. The plan is to have the required changes for CEP4 production-ready by December making this the top priority and main activity for LOFAR software development in the coming period. Changes will include a further move towards implementation of services that will contribute to a responsive LOFAR instrument.


CITT Status (E. Orru & T. J. Dijkema):

- Extensive documentation on the CITT 1 results will be provided soon both on the Wiki and at www.astron.nl/citt/.

- The CITT 2 will focus on development and implementation of algorithms that extend the capabilities of the imaging pipelines of the Radio Observatory, in particular:

  • Integration in the RO pipelines and in the production system of the CITT1 results. NDPPP, awimager2, generic pipeline, pre-calibration strategy, FACTOR.
  •  Research activities aimed to calibrate the LBA and to improve and optimise the algorithm of low level tasks (ndpp, awimager)

The CITT 2 started formally on October 1st. During the first moths of the project, the team will focus on optimizing the FACTOR pipeline, to make it eventually available to users for commissioning as soon as possible. 

- The new awimager has now been integrated into the standard lofar build accessible through 'use LofIm', it can be called using the command awimager2. 



MSSS status (G. Heald):


The first MSSS paper presenting Verification Field data has been accepted for publication in Astronomy & Astrophysics. A revised MSSS-HBA catalog of 140,000 sources has been distributed to the MSSS team for quality control. Work toward the final flux scale is now concluding, and a potential improvement to the mosaicing technique is being investigated.


Observing Programmes and miscellaneous items:


- Cycle 4 observing programme: 80% complete. The rest is scheduled for completion by November 14th 2015. The Cycle 4 observing schedule is available here.

- Cycle 3 observing programme: 91 % complete - Remaining 9% is being observed with second priority during Cycle 4. Unfinished projects will not continue during Cycle 5.

- 35 Cycle 5 proposals have been received, of which 25 are regular and 10 are long-term proposals. The oversubscription factors for the observing and processing categories are 1.8 and 1.6, respectively. The PC meeting will take place on October 28th - 29th 2015. Cycle 5 will start on November 15th 2015.

- An error was found in the settings of the phase-only calibration parset of the Radio Observatory Imaging Pipeline. The error was fixed on June 26th. A full description of the issue, as well as instructions on how to fix the data, is given here.


CEP news:


- CEP2:

  • Disk space situation is often critical, especially in case of instability of the processing and ingest systems and after week-ends. 
  • A few locus nodes experienced issues and were temporarily taken out of production.

- CEP3:

  • Cluster info and schedule available here.
  • Monitoring of node usage is active. Statistics will be used to evaluate requests for extensions.


Calendar next LOFAR activities:


-       Next LSM's : 28/10, 11/11, 25/11, 9/12

(note: all presentations given at the LSM are available here).

-       Next Stop days: 10/11, 01/12, 05/01

-       Next software roll outs: 02/11, 07/12

-       KSP Pis meeting: 19/11

-       Next LOFAR bulletin: December 2015.

Design: Kuenst.    Development: Dripl.    © 2022 ASTRON