Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measuring the Allan Variance by Sinusoidal Fitting   The Allan variance of signal and reference frequencies is measured by a
least-squares fit of the output of two analog-to-digital converters (ADC's) to
ideal sine waves. The difference in the fit phase of the two channels generates
the timing data needed for the Allan variance. The fits are performed at the
signal frequency ($\approx 10 $ MHz) without the use of heterodyning.
Experimental data from a modified digital oscilloscope yields a residual Allan
deviation of $3 \times 10^{-13}/\tau $, where $\tau$ is the observation time in
sec. This corresponds to a standard deviation in time of $<$ 300 fs or 20
$\mu$Rad in phase. The experimental results are supported by statistical theory
and Monte Carlo simulations which suggest that optimized devices may have one
or two orders of magnitude better performance.

2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org