The details:


o China:

  Major problems:  - only very limited view on sky/Galactic plane
                   - Small number of beams within tiny FOV
                   - number of sub-arrays too small
                   - Upper frequency (6 GHz) limits science
                     particularly for inner Galaxy (potentially
                     most interesting)
                   - Baseline is too small to provide astrometry
                   - Dynamic range

  Advantages:  there are no particular advantages for pulsar science
               over the other designs

  Solutions:  The fundamental problems may only be solved with a
              a massive 'add-on' from one or more of the other designs.
              But that would then look more like a KARST-add on
              to the other designs rather than the other way round.

  Summary:    There are simply too many problems to be solved: NO


o Europe:

  Major problems:  - Frequency limit: 1.4 GHz is simply not high
                     enough to do most of the science
                   - Similarly bandwidth: this needs to be much larger,
                     at least a factor of 5-10 at the higher frequency
                     end (consequences for correlator)
                   - Restricted sky coverage/sensitivity, in
                     particular for low elevations

  Advantages:  Can observe the whole sky at once with a large number
               of beams. Ideal instrument for timing lots of pulsars.

  Solutions: The major problems and a couple of 'minor' ones (e.g.
             current baseline too small) could be solved quite
             reasonably with the addition of extra stations of another
             design. However, sufficient sensitivity is still needed
             at higher frequencies (1-15 GHz), so that the fraction of
             high-frequency design must be substantial.

   Summary:  Given the advantage of the design (hugely attractive for
             pulsars), with some efforts and add-ons from other designs
             the problems can be solved:  MAYBE

o India:

  Major Problems:  - Difficult to judge as I am missing some
                     information about performance at high frequencies
                     Depending on design that could be a severe
                     problems. It may not meet our high frequency
                     requirement (10-15 GHz).
                   - Similarly, baseline.
                   - Small number of beams within FOV (1!), i.e.
                     possible severe sacrifice of sensitivity for independent
                     beams

  Advantages:  Easy to sub-array.

  Solutions:   Improved antenna design and possible hybrid with others

  Summary:  MAYBE

o Lueneburg Lens:

  Major Problems: - Limited frequency range and bandwidth,
                    both, which I understand, are fundamental to
                    design
                  - Small number of beams within FOV (~2)


  Advantages:  Large FOV but probably without mean to make best use of it

  Solutions:   Similar to the European design, it may be an attractive
               core area design

  Summary:   MAYBE

o Cylindrical reflector:

  Major Problems:   - number of individual beams/sub-arrays

  Advantages:  Meets most of the other criteria and provides large
               frequency range though this may fall a bit short at
               the high end

  Solutions:   Adding high-frequency stations which will also add
               to the number of sub-arrays

  Summary:   MAYBE

o USA:

  Major Problems:  - Small number of beams within FOV (1!), i.e.
                     possible severe sacrifice of sensitivity for independent
                     beams

  Advantages:  Superb frequency coverage (although at the highest end
               the bandwidth may be too small), easy to sub-array

  Solutions:   Adding designs with multiple beams within FOV for
               core area

  Summary:  MAYBE

o Canada:

  Major Problems:  - Small number of beams within FOV
                   - number of sub-arrays too small
                   - Limited sky coverage and apparent loss in
                      sensitivity for low elevations
                   - I am not clear about the baselines we are
                     talking about here
                   - Dynamic range


  Advantages:  Very good frequency coverage (although at the highest end
               the bandwidth may be too small)

  Solutions:   Focal plane sampling for multiple beams and adding
               which allow large number of sub-arrays

  Summary:  Although it share some problems with the KARST design,
            the frequency coverage is far better so that other problems
            may be resolvable in a hybrid system:  MAYBE


Source: Michael Kramer from WG2