Wrong position coordinates for station DE605

Data taken before April 20, 2017 had wrong position coordinates for station DE605 reported in the metadata. An estimate of the effect on relevant observing modes is given below.

  • Interferometric mode:
    Based on the LCBS survey catalog (Jackson et al. 2016, A&A, 595, A86), source detection rates on baselines between the phased LOFAR core and DE601 as well as DE605 are found to be consistent with each other within 5%. This conclusion is robust against ionospheric effects, since DE601 is located close to DE605 (55 km distance). Thus, the station position difference error does not have an effect on interferometric observations performed prior to the correction at the cited significance level.
  • Pulsar timing in stand-alone mode:
    The data before the fix are beam-formed correctly to the off-set phase center, as the error is less than one phase wrap. This ANTENNA position should be used in the analysis for those dates. After the correction, the data is beam-formed correctly to the new phase center. For combining the data between these two parts, treat it as two telescopes, or make a conversion between the two systems. If this is not done, there is an error of order 100 ns between the two positions, which is AZ/EL dependent.

  • The current up-to-date DE605 coordinates are:
    # ITRF2005 target_date = 2017.5
    # Created: 2017-04-13 08:23:22

    LBA

    4005681.284790000 450968.703003000 4926457.990

    HBA

    4005717.989780000 451028.465007000 4926424.423
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