1 / 8

Aims of Commissioning

Which dipoles to use to optimize survey speed? What tapering? Trade-off between sensitivity, FOV and low side-lobe levels Station beam stability, pointing accuracy Which frequency setups are best for our purpose? RFI spectral index, polarization and RM determination

drea
Download Presentation

Aims of Commissioning

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Which dipoles to use to optimize survey speed? What tapering? Trade-off between sensitivity, FOV and low side-lobe levels Station beam stability, pointing accuracy Which frequency setups are best for our purpose? RFI spectral index, polarization and RM determination How to deal with the ionosphere 2D / 3D models? Time resolution? Quality of the final maps: uniformity of noise, detectability of extended structure, stability of the psf and sensitivity all as a function of declination Overall issue: what limits the dynamic range? Long baseline to be included in any observations? Aims of Commissioning

  2. MS3 • Cosmology WG will use MS3 to extract the cosmological dipole signal. • Enables one to assess the relative flux calibration over the whole survey area (see Blake & Wall 2002 for NVSS) • Also need to see how LOFAR performs at low elevation and where there are bright sources etc

  3. Lensing (N. Jackson) • PSF stability • Sources must have suitable structure on the right angular scales (baselines of 30-50km at highest freqs with 8-10 stations on these baselines) • Sources with minimum of 1Jy -> 3C sources • 3 objects of different sizes to start with • The double quasar 0957+561 • Later on - Abell 2218 • Preferably keep UV data to test various way of recovering the structure - only need small field, can average in frequency if RFI OK

  4. AGN surveys (P. Best & G. Miley) • Deep fields at multiple frequencies • Test different frequency bandpass coverage, to optimize calibration • Test changes to the LBA dipoles within a station • Tiling beams in deep observations to check pointing related errors • Tests of sensitivity at low and high elevation (with deep fields - not just MS3)

  5. Nearby Galaxies (J. Conway) • No official requirements yet - but see magnetism KSP requirements which will probably be the main driver • But for studying AGN structures need high dynamic range in the presence of a >1Jy source • Need a range of sources with different levels of compactness

  6. Magnetism • Separate KSP but needs to feed in commissioning requirements as well - overlap with surveys KSP

  7. At the full range of frequencies: a low and high elevation field (LH, Bootes, XMM-LSS?) Especially at 30 MHz: different selections of dipoles, also combined with 60 Mhz observations at 120 MHz: range of bandwidths how low can we go (in frequency and declination)? how well at zero declination - extremely important for the deep fields? At the survey frequencies two deep fields 5 pointings in a hexagonal grid At a depth comparable to the proposed ‘tier-1’ all sky surveys ~100 hours for the high declination and ~200 hours for low declination field Lenc field Coma cluster A giant radio source Deep observations of a few very bright sources with different levels of extended structure A simple galactic field Galactic center (also tests the declination limits in addition to opening up science possibilities) All the observations with long baselines at 0.25 sec. First list of commissioning observations p. 21

  8. Commissioning Aims List of observations Organization Manpower PhD students /postdocs Busy week List of science projects/papers Proposals

More Related