1 / 10

Kevin Sterne (Space@VT)

Summary of tdiff Calibration at Blackstone. Kevin Sterne. SuperDARN Weekly Group Meeting. Kevin Sterne (Space@VT). Sept. 13, 2016. Elevation angle with SuperDARN. Use of second array. Radarhut. Need to calibrate difference in time. Don’t forget electronics as well!.

nbennett
Download Presentation

Kevin Sterne (Space@VT)

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. Summary of tdiff Calibration at Blackstone Kevin Sterne SuperDARN Weekly Group Meeting Kevin Sterne (Space@VT) Sept. 13, 2016

  2. Elevation angle with SuperDARN • Use of second array Radarhut Need to calibrate difference in time.Don’t forget electronics as well! Kevin Sterne (Space@VT) bkstdiffcal Sept. 13, 2016

  3. Ground coax calibration • Use of open end transmission line characteristics • Two methods: vary frequency/look for nulls; use of S11 with network analyzer Kevin Sterne (Space@VT) bkstdiffcal Sept. 13, 2016

  4. Find Null Method • Use of 2-channel o-scope to do math on signals • Vary frequency until the math trace is minimized • Ray one-off method (used April 2014) Kevin Sterne (Space@VT) bkstdiffcal Sept. 13, 2016

  5. Network Analyzer Method • Measure S11 expanded phase with network analyzer • Chose frequency points and measure phase • Average over several pairs to get value • Used by UAF crew for MSI radars • Used by Kevin/Mike for Kap replacement; found ~inch precision over 950’ length Kevin Sterne (Space@VT) bkstdiffcal Sept. 13, 2016

  6. Tdiff calculation • tdiff is two parts: ground coax + electronics • Electronics calibration: • What are the different paths between main array and interferometer array? Radar hut Kevin Sterne (Space@VT) bkstdiffcal Sept. 13, 2016

  7. Leicester Electronics (2008 – June 2011) • Electronics calibration performed with vector voltmeter and Leicester procedures • Measurement ofeach beam, 1 MHzcombination • Produced tdiffsas a function offreq. Used average,fudge factor. Kevin Sterne (Space@VT) bkstdiffcal Sept. 13, 2016

  8. VT Electronics (Sept. 2011 – March 2014) • Tdiff not calibrated until April 10, 2013 • Remeasured July 2013; RX path adjusted • Involved adding extra lengths of cable until phases matched • Freq independent Kevin Sterne (Space@VT) bkstdiffcal Sept. 13, 2016

  9. VT/DDS Electronics • DDS System from USask installed March 2014; initial calibration done during install • Electronics, ground coax length rechecked April 2014 Kevin Sterne (Space@VT) bkstdiffcal Sept. 13, 2016

  10. Where are we now? • Many lines in hdw.dat file • Simon/Ray suspect current value is not correct on case study basis • No study oncorrect valueover range oftimes. Kevin Sterne (Space@VT) bkstdiffcal Sept. 13, 2016

More Related