The Efficiencies of the 45-m Radiotelescope in 2013-2014 Observing Seasons

Measured between December 2013 - January 2014


    
    
    Reciver

    Frequency
[GHz]
    HPBW*
[arcsec]
    Main Beam
Effic [%]
    Aperture
Effic [%]
    Calib.
source
    comments
      
    
    
      

      
    
    S80
    75
    22.6+-0.2
    41+-2
    31+-1
    Mars
      
    
    

      

      
    
    S100
    86
    18.8+-0.1
    44+-2
    36+-2
    Mars
      
    
    110
    16.4+-0.1
    36+-2
    24+-1
    Mars
      
    
    115
    15.0+-0.1
    29+-1
    21+-1
    Mars
      
    
    

      

      
    
    TZ1(H)
    86
    19.6+-0.1
    41+-2
    31+-1
    Mars
      
    
    110
    16.0+-0.1
    37+-2
    26+-1
    Mars
      
    
    115
    15.0+-0.1
    29+-1
    22+-1
    Mars
      
    
    

      

      
    
    TZ1(V)
    86
    19.8+-0.1
    40+-2
    31+-1
    Mars
      
    
    110
    16.0+-0.1
    37+-2
    26+-1
    Mars
      
    
    115
    15.0+-0.1
    31+-2
    24+-1
    Mars
      
    
    

      

      
    
    TZ2(H)
    86
    20.1+-0.2
    46+-2
    33+-2
    Mars
      
    
    110
    16.7+-0.1
    38+-2
    25+-1
    Mars
      
    
    115
    15.7+-0.1
    38+-1
    26+-1
    Mars
      
    
    

      

      
    
    TZ2(V)
    86
    20.0+-0.2
    47+-2
    34+-2
    Mars
      
    
    110
    16.5+-0.1
    34+-2
    23+-1
    Mars
      
    
    115
    15.3+-0.1
    34+-2
    24+-1
    Mars
      
    
    

      

      
    
    T70(H)
    75
    22.2+-0.2
    46+-2
    38+-1
    Mars
      
    
    86
    19.5+-0.2
    42+-2
    31+-1
    Mars
      
    
    

      

      
    
    T70(V)
    75
    21.6+-0.2
    44+-2
    36+-2
    Mars
      
    
    86
    19.4+-0.2
    40+-2
    31+-2
    Mars
      

    
    
      
    
    
         *) Calculated value obtained from the beamwidth measured on Mars and a correction factor.
         This correction factor is due to the effect of increased beamwidth caused by convolution
         of the real beamwidth and the diameter of Mars.

The error of the efficiencies is mainly due to uncertainty of brightness temperature of the planet.

Brightness Temperatures (T_b) of the Source (We used temperatures compiled by Shibata 1990)
Mars
- Mars 210 K (assumed based on compiled data by Shibata, 5 % error is also assumed)
- The brightness temperature of Mars is known to change depending on the distance to the Sun (R). According to Ulich (1981), the approximate formula to obtain effective Tb is Tb(effective) = Tb x (1.524 AU / R)1/2. The value of R is taken from Japanese Ephemeris.
Diameter of the Planet
The value is taken from the ASTRONOMICAL ALMANAC.
References
- Shibata, Internal Memorandum: Brightness temperatures of Venus, Mars, and Saturn (1990)
- THE ASTRONOMICAL ALMANAC(2013)
- THE ASTRONOMICAL ALMANAC(2014)
- Ulich, Astron. J. 86, 1619 (1981)

2014-04-01

Reciver	Frequency [GHz]	HPBW* [arcsec]	Main Beam Effic [%]	Aperture Effic [%]	Calib. source	comments

S80	75	22.6+-0.2	41+-2	31+-1	Mars

S100	86	18.8+-0.1	44+-2	36+-2	Mars
	110	16.4+-0.1	36+-2	24+-1	Mars
	115	15.0+-0.1	29+-1	21+-1	Mars

TZ1(H)	86	19.6+-0.1	41+-2	31+-1	Mars
	110	16.0+-0.1	37+-2	26+-1	Mars
	115	15.0+-0.1	29+-1	22+-1	Mars

TZ1(V)	86	19.8+-0.1	40+-2	31+-1	Mars
	110	16.0+-0.1	37+-2	26+-1	Mars
	115	15.0+-0.1	31+-2	24+-1	Mars

TZ2(H)	86	20.1+-0.2	46+-2	33+-2	Mars
	110	16.7+-0.1	38+-2	25+-1	Mars
	115	15.7+-0.1	38+-1	26+-1	Mars

TZ2(V)	86	20.0+-0.2	47+-2	34+-2	Mars
	110	16.5+-0.1	34+-2	23+-1	Mars
	115	15.3+-0.1	34+-2	24+-1	Mars

T70(H)	75	22.2+-0.2	46+-2	38+-1	Mars
T70(H)	86	19.5+-0.2	42+-2	31+-1	Mars

T70(V)	75	21.6+-0.2	44+-2	36+-2	Mars
T70(V)	86	19.4+-0.2	40+-2	31+-2	Mars

*) Calculated value obtained from the beamwidth measured on Mars and a correction factor. This correction factor is due to the effect of increased beamwidth caused by convolution of the real beamwidth and the diameter of Mars.

The Efficiencies of the 45-m Radiotelescope during 2013-2014