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 <<O>>  Difference Topic PointingFocusCheckSurface (r1.4 - 10 Dec 2007 - DanaBalser)
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of these objects should be visible at any time. The file calibrators.dat can be used to view the source locations within the CLEO scheduler. N. B., the flux densites listed below are approximate values taken from Peng et al. (2000).

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of these objects should be visible at any time. The CLEO scheduler can be used with the flux density catalog to check source locations. N. B., the flux densites listed below are approximate values taken from Peng et al. (2000).


 <<O>>  Difference Topic PointingFocusCheckSurface (r1.3 - 03 Jan 2006 - DanaBalser)
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values taken from Peng et al. (2000). The antenna temperatures calculated by GFM must be corrected for the atmosphere.

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values taken from Peng et al. (2000).

The antenna temperatures calculated by GFM must be corrected for the atmosphere. The antenna temperature corrected for the atmosphere is given by

T^{'}_{a} = T_{a} exp(\tau_{o}/sin(E)),

where \tau_{o} is the zenith opacity, and E is the elevation. The zenith opacity can be estimated from the High Frequency Weather Page.

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The antenna temperature corrected for the atmosphere is given by T^{'}_{a} = T_{a} exp(\tau_{o}/sin(E)), where \tau_{o} is the zenith opacity, and E is the elevation.


 <<O>>  Difference Topic PointingFocusCheckSurface (r1.2 - 22 Dec 2005 - DanaBalser)
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A simple method to measure the efficiency of the primary surface shape

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A simple method to measure the efficiency of the primary surface

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/home/astro-util/pointing/procs, will perform Peak and Focus

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/home/astro-util/pointing/astrid, will perform Peak and Focus


 <<O>>  Difference Topic PointingFocusCheckSurface (r1.1 - 20 Dec 2005 - DanaBalser)
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%META:TOPICINFO{author="DanaBalser" date="1135104720" format="1.0" version="1.1"}% %META:TOPICPARENT{name="PointingFocus"}%

Pointing and Focus - Check Surface

  Introduction     General Strategy     Observing Details     Check Surface     Pointing Catalog  

A simple method to measure the efficiency of the primary surface shape is to perform pointing observations toward flux density calibration sources. Here we are concerned with checking that the primary surface has not degraded (e.g., snow or ice sticking to the primary). The scheduling block checkSurface.sb, located at /home/astro-util/pointing/procs, will perform Peak and Focus observations for this purpose. We recommend observations at L, X, and Q-band depending on the circumstances. Table 1 lists the expected properties for these three observing bands. Table 2 lists some properties of three flux density calibration sources. At least one of these objects should be visible at any time. The file calibrators.dat can be used to view the source locations within the CLEO scheduler. N. B., the flux densites listed below are approximate values taken from Peng et al. (2000). The antenna temperatures calculated by GFM must be corrected for the atmosphere.

The antenna temperature corrected for the atmosphere is given by T^{'}_{a} = T_{a} exp(\tau_{o}/sin(E)), where \tau_{o} is the zenith opacity, and E is the elevation.


Table 1: Receiver Band Properties

Receiver Frequency Beam FWHM Gain
L-band 1.4 GHz 8.6 arcmin 2 K/Jy
X-band 9.0 GHz 1.3 arcmin 2 K/Jy
Q-band 43 GHz 0.28 arcmin 1 K/Jy


Table 2: Calibrator Properties

Source Common Name Flux Density Antenna Temperture
L-band      
0542+4951 3C147 20 Jy 40 K
1331+3030 3C286 14 Jy 28 K
2107+4214 NGC7027 1.9 Jy 3.8 K
X-band      
0542+4951 3C147 4.7 Jy 9.4 K
1331+3030 3C286 5.1 Jy 10 K
2107+4214 NGC7027 6.0 Jy 12 K
Q-band      
0542+4951 3C147 0.9 Jy 0.9 K
1331+3030 3C286 1.5 Jy 1.5 K
2107+4214 NGC7027 5.0 Jy 5.0 K

-- DanaBalser - 20 Dec 2005


Topic PointingFocusCheckSurface . { View | Diffs | r1.4 | > | r1.3 | > | r1.2 | More }
Revision r1.1 - 20 Dec 2005 - 18:52 GMT - DanaBalser
Revision r1.4 - 10 Dec 2007 - 20:02 GMT - DanaBalser
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