Fred Schwab's Home Page

11 Sept 2016 GBT Holography

07 August 2016 GBT Holography

15 August 2015 GBT Holography Map

13 September 2015 GBT Holography Map

18 August 2015 Leica Scan Data

Data on Individual Scans

Fits using uniform data weights:

Fits with data weights proportional to -15dB illumination taper:

Fits with data weights proportional to -15dB illumination taper, squared:

Differencing of Scans

Recent Activities


  • 28Apr2014 Leica P40 Scan Summary (click here)
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  • Illustration of the apparent "stitching" artifact in the Leica P40 data
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    Baseline Scans (with grav corr for elev 31.013deg erroneously applied):
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 1 (Speed, 6.3mm@10m, Normal)
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 2 (Speed, 6.3mm@10m, High)
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 3 (Range, 6.3mm@10m, High)
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 4 (Speed, 3.1mm@10m, Normal)
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 5 (Speed, 3.1mm@10m, High)

  • Bump Test #1 Scans (w/grav corr for 11.999 deg):
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 6 (Speed, 6.3mm@10m, Normal)
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 7 (Speed, 6.3mm@10m, High)
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 8 (Range, 6.3mm@10m, High)
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 9 (Speed, 3.1mm@10m, Normal)

  • Bump Test #2 Scans (w/grav corr for 6.671 deg):
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 10 (Speed, 6.3mm@10m, Normal)
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 11 (Speed, 6.3mm@10m, High)
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 12 (Range, 6.3mm@10m, High)
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 13 (Speed, 3.1mm@10m, Normal)

  • Verification Scan (w/grav corr for 2.548 deg):
  • Preliminary Analysis of 28Apr2015 Leica P40 Scan 14 (Range, 6.3mm@10m, High)


  • Gravitational Zernike Plots, 27May2015

  • Leica scanner data from 28Apr2015 showing damage to the interior of two panels: one in Tier 9 and one in Tier 12. Are these the ones that Toney was referring to?





  • Frederic R. Schwab
    National Radio Astronomy Observatory
    520 Edgemont Road
    Charlottesville, VA 22903-2475
    USA
    (434) 296-0331, Fax (434) 296-0278
    fschwab@nrao.edu