<p>Answer to that one: What you describe is a measurment, not a calculation.<br>
The measurment you describe varies the potential difference at a satellites Langmuir probe. The potential difference then attracts or deflects ions, and deflects or attracts electrons. Those electrons and ions <em>are</em> the current being picked up by the Langmuir probe.<br>
Then follows a translation of current into local ion or electron densities. Different ion species can be distinguished w.r.t each other because they have different inertia, and thus different arrival times. I'm not sure how many ion species one can distinguish however in this way.</p>

CC BY-SA 4.0
2019-09-22T02:56:23.070Z
2019-09-22T02:56:23.070Z
AtmosphericPrisonEscape
<p>How can parameters of the <a href="https://en.wikipedia.org/wiki/Ionosphere" rel="nofollow">ionosphere</a> be calculated? Specifically, how do we calculate total ion density, total ion temperature and individual major ion densities from I-V Characteristics curve of ionospheric plasma. The <a href="https://en.wikipedia.org/wiki/Current%E2%80%93voltage_characteristic" rel="nofollow">I-V characteristics</a> curve is obtained using ion Retarding Potential Analyzer (RPA) onboard a spacecraft.</p>

<atmosphere><earth-observation>
How can parameters of the ionosphere be calculated?
MPJ
# How can parameters of the ionosphere be calculated?

(Asked by: username_0 on 2016-09-03)

How can parameters of the [ionosphere](https://en.wikipedia.org/wiki/Ionosphere) be calculated? Specifically, how do we calculate total ion density, total ion temperature and individual major ion densities from I-V Characteristics curve of ionospheric plasma. The [I-V characteristics](https://en.wikipedia.org/wiki/Current%E2%80%93voltage_characteristic) curve is obtained using ion Retarding Potential Analyzer (RPA) onboard a spacecraft.

**Tags:** atmosphere, earth-observation


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## 1 answers

### Answer by username_1 on 2019-09-22. Score: 2

Answer to that one: What you describe is a measurment, not a calculation.  
The measurment you describe varies the potential difference at a satellites Langmuir probe. The potential difference then attracts or deflects ions, and deflects or attracts electrons. Those electrons and ions *are* the current being picked up by the Langmuir probe.  
Then follows a translation of current into local ion or electron densities. Different ion species can be distinguished w.r.t each other because they have different inertia, and thus different arrival times. I'm not sure how many ion species one can distinguish however in this way.


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