<p>So, after some discussion and paper reading I learned of the sigma_z calculation in this paper by <a href="http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1997A%26A...326..924M&amp;defaultprint=YES&amp;filetype=.pdf" rel="nofollow noreferrer">Matsakis, Taylor, and Eubanks</a>. Several astronomers recommended this to me. I was also told to try out Stable32, although I'm not sure if that will work for pulsars. The code for a sigma_z calculation can be found here: <a href="https://tycho.usno.navy.mil/pulsar/sigmaz/sigmaz.html" rel="nofollow noreferrer">sigma_z calculation</a>. I believe this is the best method for doing what I asked. </p>

CC BY-SA 4.0
2019-08-02T18:49:32.017Z
2019-08-02T18:49:32.017Z
Maria
<p>I am studying pulsar timing this summer and have come across many Allan Deviation plots that include several popular clocks alongside pulsar measurements, like this one by <a href="https://tf.nist.gov/general/pdf/2166.pdf" rel="nofollow noreferrer">N. Ashby and D.A. Howe</a>: <a href="https://i.sstatic.net/f5FZ0.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/f5FZ0.png" alt="Fractional Frequency Stability"></a></p>

<p>I am unclear as to where to start. What equation would be appropriate? I have pulsar timing data from the <a href="https://data.nanograv.org/" rel="nofollow noreferrer">NANOGrav Public Data Set</a>, which I am able to view through Tempo2 (aka will be able to view it as soon as I figure out how Tempo2 works). If there is other software anyone would recommend for this task that would also be helpful.</p>

<p>I am also unsure where the data for the other clocks would be publicly available. I am hoping a scientist who has done a similar calculation can point me in the right direction. </p>

<time><software><pulsar>
How do I calculate Allan Variance (maybe for pulsars)?
Maria
# How do I calculate Allan Variance (maybe for pulsars)?

(Asked by: username_0 on 2019-07-29)

I am studying pulsar timing this summer and have come across many Allan Deviation plots that include several popular clocks alongside pulsar measurements, like this one by [N. Ashby and D.A. Howe](https://tf.nist.gov/general/pdf/2166.pdf): [![Fractional Frequency Stability](https://i.sstatic.net/f5FZ0.png)](https://i.sstatic.net/f5FZ0.png)

I am unclear as to where to start. What equation would be appropriate? I have pulsar timing data from the [NANOGrav Public Data Set](https://data.nanograv.org/), which I am able to view through Tempo2 (aka will be able to view it as soon as I figure out how Tempo2 works). If there is other software anyone would recommend for this task that would also be helpful.

I am also unsure where the data for the other clocks would be publicly available. I am hoping a scientist who has done a similar calculation can point me in the right direction.

**Tags:** time, software, pulsar


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## 1 answers

### Answer by username_0 on 2019-08-02. Score: 2 | Accepted answer

So, after some discussion and paper reading I learned of the sigma\_z calculation in this paper by [Matsakis, Taylor, and Eubanks](http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1997A%26A...326..924M&defaultprint=YES&filetype=.pdf). Several astronomers recommended this to me. I was also told to try out Stable32, although I'm not sure if that will work for pulsars. The code for a sigma\_z calculation can be found here: [sigma\_z calculation](https://tycho.usno.navy.mil/pulsar/sigmaz/sigmaz.html). I believe this is the best method for doing what I asked.


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