Lband narrow SEFD, Gain, Tsys (daytime)


       The gain, system temperature, and SEFD as a function of zenith angle were measured using correlator position switching (with cal on/offs). The measurements were done in the daytime during  jun00 and july00:
  • 23jun00 : J1120+143
  • 30jun00 : J0329+279, J0431+206, J1021+219
  • 06jul00  : J0521+166, J0840+132
  • 12jul00  : J0318+164, J0521+166, J0840+132, J1120+143

  • The measurements were done at 1400 Mhz with a bandwidth of 25 Mhz. The fluxes were taken from the NVSS survey.  The plots have polA as a dotted line and polB as a dashed line.  They are:

    1. The SEFD (system equivalent flux density) versus zenith angle. Some of the polA values are high (see note (a) below). The solid line is the SEFD measured in june of 1998.
    2. The system temperature vs zenith angle (using 1.85, 1.91 Kelvins for the cal values). The solid lines are the june 1998 Tsys scaled to the current Tsys at za of 5 degrees.
    3. The gain versus zenith angle  in kelvins per Jansky using the flux from NVSS and tsys measured using the cal. The solid line is the gain from june 1998 scaled to the current gain za of 5.
    4. The stability of the cals for each strip (calKelvins/(calon-caloff)). For a given strip the attenuation was not changed so the cal difference should be a constant.
    (a). The receiver's cryogenics was warmed up and then cooled down during the first part of july. After the cycle, the polarization A Tsys increased by 4 degrees kelvin.

    The plots can be found at:
    versus za:
     lbn SEFD, gain, and tsys vs za (ps)
     lbn SEFD, gain, and tsys vs za (pdf)

    versus azimuth:
     lbn SEFD, gain, and tsys vs azimuth (ps)
     lbn SEFD, gain, and tsys vs azimuth (pdf)

    Processing: x101/lb/Aug00/lbnjun00/
    plotting  : x101/lb/Aug00/lbnjun00.lbnplt{az,za}.pro