next up previous contents
Next: Quantization efficiency Up: The interferometric point source Previous: System temperature   Contents

Power and sensitivity measured at the correlator output for one baseline

After the atmopheric calibration that converts the measurement scale from the correlator output (in counts) to the \ensuremath{T_\ensuremath{\mathrm{a}}^\star} scale, the output of the correlator for one correlation is a power equivalent temperature (in the Rayleigh-Jeans domain), which is sampled at a rate of $2\ensuremath{d\nu}$, where \ensuremath{d\nu} is the frequency bandwidth over which the power is measured. As explained in the previous section, the standard deviation of each power measurement is given by the system temperature power ( \ensuremath{T_\ensuremath{\mathrm{sys}}}). During the integration time ( \ensuremath{\Delta t_\ensuremath{\mathrm{}}}), $2\ensuremath{d\nu}\,\ensuremath{\Delta t_\ensuremath{\mathrm{}}}$ independent samples of the signal power are measured to ensure the Nyquist sampling of the signal in the bandwidth \ensuremath{d\nu}. The signal power is averaged over these independent samples. The uncertainty on the averaged signal power, named sensitivity ( \ensuremath{\sigma_\ensuremath{\mathrm{K}}}), is thus standard deviation of the average or

\begin{displaymath}
\ensuremath{\sigma_\ensuremath{\mathrm{K}}} = \frac{\ensure...
...emath{d\nu}\,\ensuremath{\Delta t_\ensuremath{\mathrm{}}}}}.
\end{displaymath} (2)


next up previous contents
Next: Quantization efficiency Up: The interferometric point source Previous: System temperature   Contents
Gildas manager 2023-06-01