Efficiency [ | 20010-2011 | 2009-2010 |2008-2009 | 2007-2008 | 2006-2007 | 2004-2006 | 2002-2004 | 2001 | before 2001 ]

The efficiencies of the 45-m radiotelescope 2008-2009

Measured between Dec. 2008 and Apr. 2009

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Receiver  Frequency   HPBW     Aperture    Main beam  Calib.     EL.   comment
            (GHz)   (arcsec)   effic(%)    effic(%)   source
-------------------------------------------------------------------------------
 
S80          86     18.2+-0.1   38+-2      43+-2     Saturn     56-60
                                                     3C273      54-56 
            110     14.5  0.1   31  3      37  3     Saturn     30-42
                                                     3C273      30-42
            115     15.5  0.2   18  2      27  3     Saturn     30-43
                                                     3C273      55-52

S100         86     18.1  0.1	41  2	   47  2     Saturn     56-60
                                                     3C273      54-56
            110     14.3 0.04	36  3	   43  3     Saturn     30-42
                                                     3C273      30-42
            115     14.7  0.1	23  3	   31  3     Saturn     30-43
                                                     3C273      55-52

T100(H)      86     18.3  0.1	37  2	   43  2     Saturn     62-60
                                                     3C273      56-54
            110     15.3  0.2	31  3	   40  4     Saturn     37-38
                                                     3C273      36-39             
            115     15.4  0.1	24  3	   36  3     Saturn     57-54
                                                     3C273      54-52

T100(V)      86     18.4  0.1	36  2	   42  2     Saturn     62-60
                                                     3C273      56-54
            110     15.4  0.2	33  4      44  4     Saturn     37-38
                                                     3C273      36-39
            115     15	  0.1	25  3      34  3     Saturn     57-54
                                                     3C273      54-52
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The error of the efficiencies is mainly due to uncertainty of brightness temperature of the planet.

1. Brightness Temperatures (T_b) of the Source (We used temperatures compiled by Shibata 1990)
   Saturn
   • 115 GHz 155+-11 K (Interpolation of the values at 2.1 mm and 3.1 mm)
   • 110 GHz 153+-11 K (Interpolation of the values at 2.1 mm and 3.1 mm)
   • 86 GHz 153+-5 K
2. Diameter of the Planet
   • Diameters of the planet are taken from Japanese Ephemeris. In the case of Saturn, the diameters in the polar and equatorial directions are significantly different. In Japanese Ephemeris, only the radius in the polar direction is listed. Therefore, a correction is done with the ratio (1.12) of the diameters in the two directions.
   • The effective diameter is calculated with a formula below:
     2 x (1.12 x polar radius x polar radius)^1/2.
3. References
   • Shibata, Internal Memorandum: Brightness temperatures of Venus, Mars, and Saturn (1990)
   • Japanese Ephemeris, Maritime Safety Agency of Japan (2008)

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