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The Efficiencies of the 45-m Radiotelesocpe (before 2001)

• between Dec. 2000 and Jun. 2001
• between Dec. 1999 and Jun. 2000
• between Dec. 1998 and Aug. 1999
• between Dec. 1997 and Aug. 1998
• between Dec. 1996 and May. 1997
• between Dec. 1995 and Feb. 1996
• between Nov. 1994 and Jun. 1995
• between Dec. 1990 and Jun. 1992
• between Dec. 1989 and Jun. 1990
• Figures for the elevation dependences

Effective for period between Nov.2000 and Jun. 2001

----------------------------------------------------------------------------------
Receiver  Frequency       HPBW     Aperture    Main beam  Calib.     EL.   comment
            (GHz)       (arcsec)   effic(%)    effic(%)   source
----------------------------------------------------------------------------------
H22(ch1)     23         72.7+-0.3   62+-4      81+-5     NGC7027     55-46
   (ch2)     23         71.8  0.3   61  4      78  4     NGC7027     55-46
H30          --           -----      ---        ---      -------
H40          43         39.2  0.5   55  3      74  3     Saturn      70-71
                                                         3C454.3     65-62
S40          43         39.5  0.2   57  3      77  3     Saturn      30-67   a
                                                         3C454.3     60-57
             49         34.9  0.2   51  3      70  3     Saturn      30-36   a
                                                         3C279       38-42
S80          86         18.6  0.1   41  2      49  2     Saturn      76-69
                                                         3C273       46-48
    110 100     16.3  0.1   36  4      45  4     Saturn      64-60   b
                                                         3C273       37-40
    115 110     15.4  0.2   31  3      42  4     Saturn      59-57   b
                                                         3C279       31-34
S100         86         18.2  0.1   42  2      49  2     Saturn      76-69
                                                         3C273       46-48
    110 100     16.3  0.1   41  4      51  5     Saturn      64-60   b
                                                         3C273       37-40
    115 110     15.6  0.1   35  3      48  5     Saturn      59-57   b
                                                         3C279       31-34
S115Q(ch1-4)---         ----  ---    ---        ---      -----

BEARS       112                  see below               Saturn      70-67
                                                         3C279       35-44
----------------------------------------------------------------------------------
Measured between Nov. 2000 and Dec. 2000
a: The beam sizes of the S40 receiver at 43 and 49 GHz are
   elongated for about 5 arcsec in elevation
b: Wrong frequencies were written until 2007-03-16.

The error of the efficiencies is mainly due to uncertainty of temperature of planets. The beam size in the table is the average of the values in azimuth and elevation.

1. Brightness Temperatures and Flux Density of Sources (We mainly used temperatures compiled by Shibata 1990)
   • Saturn
     • 112 GHz 153+-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)
     • 100 GHz 148+-11 K
     • 86 GHz 153+-5 K
     • 49 GHz 144+-5 K (Interpolation of the values at 3.5 mm and 9.6 mm)
     • 43 GHz 142+-5 K (Interpolation of the values at 3.5 mm and 9.6 mm)
     The brightness temperature of Saturn is reported to possibly increase about 10 %, when the inclination of the ring viewed from the Earth becomes large (Ulich 1981). This tendency is seen, when the inclination angle is larger than 23 deg. The inclination during our measurement period was about 26 deg (Astronomical Almanac, F41 & L11, B: Saturnicentric latitude of the Earth). However, this tendency does not seem to be well established. We, therefore, are not taking into account of this effect.
   • NGC 7027
     • As a flux density at 23 GHz, we used 5.86 Jy (estimated by Baars et al. 1977 at 22.235 GHz). The error (absolute accuracy) was estimated to be 5 %.
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) ^ 0.5.
3. Comments on the Results of This Period
   • Above 86 GHz, efficiencies are slightly lower than the corresponding values of the last period except for that with the S100 receiver at 110 GHz. In addition beam efficiencies with the S100 receiver at 86, 100, and 110 GHz do not smoothly change against frequency change. From comparison with the results of the last period, we think that this is due to the slightly low efficiencies with the S100 and S80 receivers at 86 GHz this period. The measurement at 86 GHz was done at relatively high elevation (76 - 69 deg). A probable reason for the slightly low efficiency is that the telescope efficiency is slightly low at such high elevation (see a graph of the intensity of Saturn vs. elevation in the appendix). In the last period the elevations were 59 - 61 deg for the 86 GHz measurement and 51 - 55 deg for the 110 GHz measurement.
4. References
   • Baars et al. Astron.&Astrophys., 61, 99 (1977)
   • Shibata, Internal Memorandum: Brightness temperatures of Venus, Mars, and Saturn (1990)
   • Ulich, Astron. J., 86, 1619 (1981)
   • Astronomical Almanac (2000)
   • Japanese Ephemeris, Maritime Safety Agency of Japan (2000)

Appendix

1. Wavelength dependence of aperture efficiency

According to the fitting results, deviation of the surface from the ideal paraboloid is 170+-6 mm. (click to enlarge)

2. Wavelength dependence of beam size

According to the linear fitting, beam size can be expressed as follows: beam size (arcsec) = -0.21287 + 5.597 x Lambda (mm). (click to enlarge)

3. Elevation dependence of beam efficiency

Data were taken during the measurements of sub-reflector adjustments. Efficiencies are the highest at 50 - 60 deg. On the other hand, the intensity is about 3 K and 1 - 2 K lower than the optimum value below 40 deg and above 65 deg, respectively. (click to enlarge)

Effective for period between Dec.1999 and Jun. 2000

-----------------------------------------------------------------------
Receiver  Frequency   HPBW     Aperture    Main beam  Calib.    comment
            (GHz)   (arcsec)   effi(%)     effic(%)   source
-----------------------------------------------------------------------
H22(ch1)     23     72.0+-0.6   64+-4      82+-4     NGC7027      a
   (ch2)     23     71.2  0.6   64  3      81  4     NGC7027      a
H30          32     52.5  0.5   63  3      84  4     S, 3C454.3
H40          43     39.1  0.2   55  2      73  3     S, 3C454.3   b
S40          43     38.2  0.2   58  2      73  3     S, 3C454.3   c
             49     33.9  0.2   53  2      68  3     S, 3C273     d
S80          86     18.9  0.2   42  2      52  2     V, 3C273
            110     15.1  0.1   34  2      44  2     V, 3C273
S100         86     18.4  0.1   45  2      53  2     V, 3C273
            110     15.0  0.1   38  2      48  3     V, 3C273
S115Q(ch1)  110     16.2  0.1   34  3      50  4     S, 3C279     e
     (ch2)  110     15.9  0.1   33  3      47  4     S, 3C279     e
     (ch3)  110     16.2  0.1   32  2      47  4     S, 3C279     e
     (ch4)  110     15.9  0.1   33  3      47  4     S, 3C279     e
------------------------------------------------------------
by S. Takano et al.
Measured between Nov. 1999 and Dec. 1999
S=Saturn, V=Venus

a: The beam size of the H22 receiver is elongated for 2 arcsec in elevation.
b: The beam size of the H40 receiver is elongated for 2 arcsec in elevation.
c: The beam size of the S40 receiver at 43 GHz is elongated for 5 arcsec in elevation.
d: The beam size of the S40 receiver at 49 GHz is elongated for 4 arcsec in elevation.
e: The beam size of the S115Q receiver is elongated for 1-2 arcsec in elevation.

The error of the efficiencies is mainly due to uncertainty of temperature of planets. The beam size in the table is the average of the values in azimuth and elevation.

1. Brightness Temperatures and Flux Density of Sources (We mainly used temperatures compiled by Shibata 1990)
   • Saturn
     • 110 GHz 153+-11 K (Interpolation of the values at 2.1 mm and 3.1 mm)
     • 86 GHz 153+-5 K
     • 49 GHz 144+-5 K (Interpolation of the values at 3.5 mm and 9.6 mm)
     • 43 GHz 142+-5 K (Interpolation of the values at 3.5 mm and 9.6 mm)
     • 43 GHz 134+-5 K (Interpolation of the values at 3.5 mm and 9.6 mm)
     The brightness temperature of Saturn is reported to possibly increase about 10 %, when the inclination of the ring viewed from the Earth becomes large (Ulich 1981). This tendency is seen, when the inclination angle is larger than 23 deg. The inclination during our measurement period was about 26 deg (Astronomical Almanac, F41 & L11, B: Saturnicentric latitude of the Earth). However, this tendency does not seem to be well established. We, therefore, are not taking into account of this effect.
   • Venus
     • 110 GHz 350+-22 K
     • 86 GHz 358+-13 K
   • NGC 7027
     • As a flux density at 23 GHz, we used 5.86 Jy (estimated by Baars et al. 1977 at 22.235 GHz). The error (absolute accuracy) was estimated to be 5 %.
2. Diameter of the Planet
   • Diameters of the planet are taken from Japanese Ephemeris (1999). 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) ^ 0.5.
3. References
   • Baars et al. Astron.&Astrophys., 61, 99 (1977)
   • Shibata, Internal Memorandum: Brightness temperatures of Venus, Mars, and Saturn (1990)
   • Ulich, Astron. J., 86, 1619 (1981)
   • Astronomical Almanac (1999)
   • Japanese Ephemeris, Maritime Safety Agency of Japan (1999)

Effective for period between Dec.1998 and Aug. 1999

-------------------------------------------------------------
Receiver  Frequency   HPBW     Aperture    Main beam  Calib.
            (GHz)   (arcsec)   effi(%)     effic(%)   source
-------------------------------------------------------------
H22(ch1)     23     73.4+-1.7   58+-2      77+-4     NGC7027
   (ch2)     23     73.8  2.4   60  2      81  6     NGC7027
H30          32     52.8  0.8   59  1      79  3     S, 0420
H40          43     39.0  0.3   54  1      71  1     S, 3C84
S40          43     39.1  0.2   54  1      72  1     S, 3C84
             49     34.5  1.3   52  1      70  6     S, 3C84
S80          86     18.4  0.3   42  2      50  2     M, 3C273
            110     14.5  0.2   35  2      42  2     M, 3C273
S100         86     18.4  0.2   49  2      58  2     M, 3C273
            110     14.5  0.2   40  2      48  2     M, 3C273
S115Q(ch1)  110     15.5  0.5   40  2      55  4     M, 3C273
     (ch2)  110     15.7  0.7   36  2      51  5     M, 3C273
     (ch3)  110     15.9  0.5   37  2      53  4     M, 3C273
     (ch4)  110     15.7  0.3   38  2      54  3     M, 3C273
------------------------------------------------------------
by S. Takano et al.
Measured between Nov. 1998 and Dec. 22, 1998
S=Saturn, M=Mars

Effective for period between Dec.1997 and Aug. 1998

------------------------------------------------------------
Receiver  Frequency   HPBW     Aperture        Main beam
            (GHz)   (arcsec)   efficiency(%)   efficiency(%)
------------------------------------------------------------
H22          23     73.8+-2.7   61+-1           83+-8(*)
H30          32     52.3  0.9   57  2           74  5
H40          43     35.2  4.5   61  4           65 19(*)
S40          43     38.8  0.7   59  2           77  4
             49     34.9  0.5   58  2           78  5
S80          86     18.2  0.3
            110     14.7  1.1   34  4           42  6
S100         86     18.3  0.5   42  2           49  4
            110     14.3  0.8   39  3           46  5
S115Q(ch 1) 110     15.9  0.6   32  2           46  4
------------------------------------------------------------
by Yonekura et al.
Measured between Dec. 27, 1997 and Jan. 4, 1998
Beamwidths: 3C273,      Efficiencies: Saturn (17")
(*) need more measurements, since they are poor S/Ns.

Effective for period between Dec.1996 and May 1997

------------------------------------------------------------
Receiver  Frequency   HPBW     Aperture        Main beam
            (GHz)   (arcsec)   efficiency(%)   efficiency(%)
------------------------------------------------------------
H30          32     53.2+-0.4   59+-3           81+-4
S40          43     39.5  0.4   61  2           81  3
             49     36.4  0.6   51  3           76  5
S80          86     17.6  1.0   44  2           47  2
            110     14.2  0.8   35  2           40  3
S100         86     17.6  1.0   46  2           50  2
            110     14.8  0.9   41  2           51  3
S115Q(ch 1) 110     16.0  1.0   36  2           53  3
     (ch 2)         15.6  1.0   36  2           52  3
     (ch 3)         15.0  1.0   33  2           43  3
     (ch 4)         15.2  1.0   37  2           49  3
------------------------------------------------------------
by Matsuo et al.

Effective for period between Dec. 1995 and Feb. 1996

----------------------------------------------------------------
Receiver  Frequency   HPBW     Aperture   Main beam  El    Wind
            (GHz)   (arcsec)   effi.(%)   effi.(%)  (deg)  (m/s)
----------------------------------------------------------------
S40          43     40.0+-0.4   61+-2     85+-2      46    1-4
             49     36.1  0.3   50  2     74  2      39    2-5
S80          86     17.9  0.6   44  2     50  3      48    3-5
            110     14.1  0.6   37  2     45  3      41    2-4
S100         86     17.7  0.6   43  2     48  3      48    3-5
            110     14.4  0.6   42  2     49  3      41    2-4
S115Q(ch 1) 110     15.9  0.3   37  2     53  2      41    1-2
     (ch 2)         15.7  0.4   38  2     54  2
     (ch 3)         18.7  0.4   30  2     60  2
     (ch 4)         15.5  0.3   37  2     51  2
------------------------------------------------------------
by Kagi et al.
Measured between Dec. 18, 1995 and Feb. 4, 1996
Beamwidths: 3C273,      Efficiencies: Saturn (16")

Effective for period between Nov. 1994 and June 1995(*)

------------------------------------------------------------
Receiver  Frequency   HPBW     Aperture        Main beam
            (GHz)   (arcsec)   efficiency(%)   efficiency(%)
------------------------------------------------------------
S40          43     39.7+-0.3   55+-2           71+-2
S80          86     19.4  0.4   30  2           39  3
            110     15.1  0.6   25  2           33  3
S100         86     20.4  0.4   31  2           46  3
            110     15.8  0.5   27  2           38  3
S115Q(ch 1) 110     17.1  0.3   28  2           48  3
     (ch 4)         16.5  0.3   27  2           42  3
------------------------------------------------------------
by Matsuo et al.
(*)  The main dish had a large astigmatism.

Effective for period between Dec.1990 and June 1992

-------------------------------------------------------------
Receiver  Frequency   HPBW     Aperture        Main beam
            (GHz)   (arcsec)   efficiency(%)   efficiency(%)
-------------------------------------------------------------
H22          23     74.4+-2.2   63+-5           77+-5     J
H30          32.5   51.3  1.2   60  5           78  6     J
S40          43     41.5  1.1   53  4           79  5     J
             49     34.9  1.1   51  6           71  7     J,S
S80          86     19.1  1.0   43  5           54  6     M,S
             98     17.0(e)     38  4           50  4     S
S100         86     20.2  1.0   39  4           55  5     J
             98     17.6  1.0   36  4           50  5     M,S
            110     15.7  0.9   37  5           52  6     M,S
M100         86     19.9  0.8   43  4           58  4     M,J
             98     17.4  1.0   42  4           58  6     S
            110     14.4  0.5   40  4           47  4     M,J
-------------------------------------------------------------
by Shibata et al.
e:  estimated
M:  Mars     J: Jupiter      S:  Saturn
The antenna surface was improved using the holography measurements
in autumn 1990.

Effective for period between Dec.1989 and June 1990

-------------------------------------------------------------
Receiver  Frequency   HPBW     Aperture        Main beam
            (GHz)   (arcsec)   efficiency(%)   efficiency(%)
-------------------------------------------------------------
H40          43     40.0+-0.5   54+-4           76+-5     J
S40          43     40.6  0.8   49  4           70  5     J
S80          86     22.0  0.8   29  4           46  4     S
S100         86     20.2  0.8   36  4           52  4     S
            110     15.4  0.5   23  3           32  3     M
M100         86     19.8  0.7   41  4           57  4     S
            110     15.2  0.3   29  3           38  4     M
-------------------------------------------------------------
by Shibata et al.
M:  Mars     J: Jupiter      S:  Saturn

Figures for the elevation dependences

Fig. 4: Elevation dependence of antenna efficiency measured on January 26/27, 1998 (Matsuo et al.).

Fig. 3: Improved elevation dependence of antenna efficiency after February 10, 1996 (Matsuo et al.).

Fig. 2: Elevation dependence of antenna efficiency of the 45-m telescope from December 1995 to February 03, 1996 (Matsuo etal.).

Fig. 1: Elevation dependence of antenna efficiency of the 45-m telescope in 1990(Shibata et al.).

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