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General Topics

• General description of the pointing model of the JCMT
• Summary - a brief summary of the terms used and how it all fits together
• Pointing FAQs - all the questions I can think of (please email me any others though)
• Current status - keep up to date with the latest checks on performance
• Record - a chronological list of all pointing related activity
• Focus Overview
• Coordinate Concepts (opens as a pdf)
• Techniques & tactics of pointing & focussing
• Problems - old and new

• History
  • ... of events affecting pointing
  • ... of residuals with SCUBA and the heterodyne FEs

• Pointing catalog
  • Overview
  • Pointing catalog - blazars, UCHIIs, the Stephenson (2005) catalog of Carbon stars (of which our catalog contains a few).
  • Notes on Individual sources
  • Upgrade to J2000 - The case of the blazars
  • Distribution of blazars
  • (Optical) Finding charts for AGN
  • ICRS - the International Celestial Reference System; the foundation of all these positions.
  • SMA list - with 0.85mm, 1mm & 3mm flux updates

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The Pointing Model

• The 7 parameters of the basic model - their algorithmic forms and illustrations showing their effects on the pointing residuals.
  • Parameter Derivation : with TPOINT
  • Clock errors, and how to check the ASM clock.

• Data Acquisition
  • Pointing run tactics
  • The LOGGER task
  • TPOINT data format
  • Observational considerations
  • Discrete pointing observations
    • The heterodyne FIVEPOINT command
    • Heterodyne spectral line pointing
  • Continuous Tracking Experiments
    • Heterodyne tracking using fives

• How to Plot JCMT Pointing Data

• Data Processing
  • Individual pointing observations can be re-reduced on ocsmaster using
    ( jac_sw/itsroot/install/tcs/bin/Linux-x86_64/) runPF
    Hint: use ../acsis09/cubes and ../dr3/reduced/*_reduced.sdf files, resp.
  • The analysis of (nightly, collected) JCMT pointing data sets is done with TPOINT
    (try here or here if the local .ps version doesn't work).
    The use of TPOINT is also described by Pat Wallace at his commercial website.
  • Single pointings may be used to update the collimations.
  • The case of multiple receptor options for pointing - as with HARP - requires knowledge of the receptor positions.
  • Full model determination and how to install the new model

• HARP K-mirror complications
  • Successful installation of K-mirror terms in April 2014.

• RxW Differential Pointing

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Inclinometry

• Inclinometry - General - what it is, and where you do it. Example data, and the track model
• Protocols
• Taking data
  • locally
  • remotely
• Trouble-shooting
• Levelling technique
• Format of inclinometry output
• How to reduce inclinometry data and install a new track model.
• Azimuths of wheel-joint interactions
• Prediction of pointing errors from track model parameters (F1,F2,F3)
• Roll
• Yaw
• F2 sign convention
• Constructing a hybrid model
• analyzing inclinometry data for harmonic components
• transit-inclinometry - see the transit step archive.
• Strain gauge data

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Other quantities affecting pointing

• Refraction
• thermal effects
• SMU & TMU alignment
• Water Vapour Meter archive (since ~ Feb 2004)
• Opacity Archives Apr 1997 - May 2005, Oct 2006 - today and Opacity & Seeing GUI
• Seeing analysis by Jason Stevens (1995)

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Documents

• Pointing Project Documents
• Search for documents on 'pointing' in JACdocs on 01 Nov 2000
• Reports to the JCMT Board
• Occasional Pointing Reports (by year)

• Pat Wallace's TPOINT program

• Related telescope documents
  • Telescope motion during slews/rasters - algorithms for accelerations & velocities

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Pointing of other submillimetre telescopes

Telescope
Pointing link	CSO	NRO	IRAM 30m in part. Greve et al, 1996. A&ASuppl. 115,3791	HHT
Telescope
Pointing link	OVRO Scott 1993	SMA Patel et al. 2004	ASTRO Stark et al 2001 PASP 113, 567	LMT
Telescope
Pointing                     link	ALMA J.G.Magnum et al 2006. PASP 118, 1257) Section 6	GBT Constantikes, 2006	CBI (26-36 GHz) useful trig formulae	APEX (200-1400 GHz)

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Time

• 2005 IAU Resolutions on Astronomical Reference Systems, Time Scales, and Earth Rotation Models (G.Kaplan, USNO)
• IERS central Bureau
• Clock errors, and how to check the ASM clock.
• NIST page on time
• IRIG-B coding of time signal
• The U.S. Naval Observatory - keepers of the Master Clock.
• The IERS product Bulletin A provides UT1-UTC for updating the TCS pointing model. Predictions for the upcoming month or so have been used in the
  past with no noticeable loss of pointing accuracy. Updating THI.tide any more frequently would be tedious. I also receive this file by email once a
  week or so - see the main IERS page for their Request form. (See How to get UT1-UTC).
  
• For other Earth rotation parameters see the IERS Earth Orientation Parameters product centre. (eg Click on 'EOP combined series' then Series of the
  current year').
• Watch the USNO pages or IERS for announcements/status of Leap Seconds.
• AAS/DDA proposal to allow UT1-UTC to exceed 1^s and to effectively eliminate the leap second.