Optics

TOPICS:

• 150907: using 3 distomats to measure the platform height
  
• 120401: Shami's report on surveying the dome (regurgitation of my web pages) (.pdf)
  
• 120618: pointing error as we move the platform vertically
  
• 120404: simulate linefeed gain vs za
  
• 120403: can we replace the 430 xmter with ring of amiser panels around the edge of the dish?
  
• 100218: notes for jim gould
  
• 080515: platform/tiedown motion during vlbi cal scan
•  070418: Platform motion as ch za moves 2 to 20 deg.
• 070415: Mapping platform Rotation to Sky rotation.
• 010716: field of view scanning and pointing losses (german cortes) (.ps) (.pdf)
• page 37,38 of Multi-beam array system feed selection. atoms-2001-03.pdf
  

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Historical events for the optics:

• 28oct12: new sbn receiver installed. The tilt sensor box was removed and then a new smaller box was installed. Need to check the alignment.
  
• 25apr06: sbn focus curve on J0745+101.
• 03,04aug05: Installed some beams in feed tower to brace some beams that were deflecting (probably from the kevlar cables).
• nov04 to jan05: PrimaryAdj2: adjust the 38000 panels of the primary using the PrimaryMeas2 data (actually not all of the panels were readjusted0.
• 12oct04-30oct04 : measure/adjust the tertiary
• 07jun04-29jun04; measure/adjust the secondary.
• 14may04: sbw horn moved down to put it at correct phase center.
• 02,08may04: horns surveyed into position. Some had been moved to make way for alfa. Also to correct for tertiary motion on 01may04.
• 01may04: tertiary survey (after alfa installed). Updated position
• 21apr04: alfa installed after reinforcing floor.
• ??apr04: kevlar cables in installed in feed tower (before alfa installed).
• 13feb04:    sbh horn down .8 inches to put it at correct phase center.
• 09jul03: ao9 survey of dome.
• mar03: PrimaryMeas2. finished measuring the photos from primary measure2
• 28feb03: sbn focus curve after dome moved.
• 27feb03: dome lifted by 1.65 inches
• 25feb03: shimming of elevation rails completed.
• 22nov02: lbw horn moved down 3.67" to put phase center at correct spot.
• 28aug02: cb horn moved down 1.08 " to put phase center in correct position.
• nov01-dec01: PrimaryMeas2. take another round of photos of 38000 reflectors on primary. machine measuring did not finish until mar03.
• oct01-nov01: PrimaryAdj1. Adjust all 38000 panels on primary.
• mar01-oct01:  PrimaryMeas1. measure photos of all 38000 reflectors on primary
• mar01: Adjust tiedown cables  under primary (2nd round using measurements from jan01)
• dec00: Adjust tiedown cables under primary

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Surveying the primary reflector (top)

Measuring only the tiedown cables (2000 targets)

• M_TD0       dec00  measure targets at reflector tiedown cables before any adjustments.
• ADJ_TD0  dec00 adjust dish at the measured tiedown cables using m_td0 data.
• M_TD1       jan01 remeasure reflector targets at tiedown cables.
• ADJ_TD1  mar01: completed second adjustment of reflector targets at tiedown cables using m_td1 data.
• M_TD2      mar01: as part of m_sur1 below just the tiedown cable targets were measured to compare with the m_td1 data.

Measuring/adjusting all 38000 targets.

• M_SUR1      mar01-oct01: All 38000 targets now installed. Take photos and then measure on measuring machine. The photo measurements  finished around oct01.
• ADJ_SUR1 oct01-nov01. After M_sur1 start adjusting all the panels. This measurement finished around nov01.
• M_SUR2      nov01-mar03. After ADJ_SUR1 take the photos in nov/dec01. Remeasure all the photos. The measurements and computations finished around mar03.

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Surveying the dome position from AO9  (top)

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Surveying the horn positions.  (top)

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Pitch, roll, and focus using theodolite and tilt sensors to compute the tiedown correction.  (top)

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Field of view measurements.  (top)

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Platform height, position, tiedown Position, and tension. (top)

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Cable measurements:  (top)

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Standing waves:  (top)

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Computations  (top)

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MISC.  (top)

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