Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A New System Noise Measurement Method Using a 2-bit Analog-To-Digital
  Converter   We propose a new method to measure the system noise temperature, $T_{\rm
sys}$, using a 2-bit analog-to-digital converter (ADC). The statistics of the
digitized signal in a four-level quantization brings us information about the
bias voltage and the variance, which reflects the power of the input signal.
Comparison of the variances in {\it hot} and {\it sky} circumstances yields
$T_{\rm sys}$ without a power meter. We performed test experiments using the
Kagoshima 6-m radio telescope and a 2-bit ADC to verify this method. Linearity
in the power-variance relation was better than 99% within the dynamic range of
10 dB. Digitally measured $T_{\rm sys}$ coincided with that of conventional
measurement with a power meter in 1.8-% difference or less for elevations of
$10^{\circ} - 88^{\circ}$. No significant impact was found by the bias voltages
within the range between -3.7 and +12.8% with respect to the threshold voltage.
The proposed method is available for existing interferometers that have a
multi-level ADC, and release us from troubles caused by power meters.

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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
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The categories of this paper are: econ
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
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The categories of this paper are: nlin
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The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org