<p>Those are Sun/Moon multispectral photometers and ski radiometers. These are instruments that can scan the sky or track the Sun/Moon for direct measurements. They measure light intensity at multiple narrow wavelength bands, and are designed to measure atmospheric aerosols content and characteristics.</p>

<p>The ones in the third image seem to be a <a href="https://www.cimel.fr/?instrument=sun-sky-lunar-multiband-photometer&amp;lang=en" rel="nofollow noreferrer">CIMEL CE-138 Sun Sky Lunar Multispectral Photometer</a> (<a href="http://cimel-wiki.recherche.usherbrooke.ca/cimel/index.php?title=CIMEL_318_-_general_specifications" rel="nofollow noreferrer">specs</a>).</p>

<p><a href="https://i.sstatic.net/mBxZ4.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/mBxZ4.png" alt="enter image description here"></a></p>

<p>There is just a few brands that make these instruments. Others are <a href="http://www.isac.cnr.it/en/infrastructures/prede-pom-01-radiometer" rel="nofollow noreferrer">Prede</a> and <a href="https://www.kippzonen.es/Download/414/POM-01-POM-02-Sky-Radiometer-and-PGS-100-Sun-Photometer-Brochure" rel="nofollow noreferrer">Kipp &amp; Zonen</a>. I don't know why they have so many at the AEMET. Perhaps it is some sort of instrumentation investigation, where they are testing different types of photometers or different wavelengths. Or perhaps, as these instruments have a filter wheel inside, each one may have a different set of filters to have higher multispectral resolution.</p>

CC BY-SA 4.0
2019-04-13T15:49:38.943Z
Thanks for the speedy answer and great sources!
uhoh
CC BY-SA 4.0
2019-04-14T02:31:36.057Z
@gansub Thanks for spotting that error. It is fixed now.
Camilo Rada
CC BY-SA 4.0
2019-04-14T14:47:40.753Z
I suspect they are sky radiometers (first line) and just under the photo "no" should be "so"
Ross Millikan
CC BY-SA 4.0
2019-04-13T15:41:57.193Z
2019-04-14T15:11:26.207Z
2019-04-14T15:11:26.207Z
Camilo Rada
<p><a href="https://twitter.com/AEMET_Izana/status/1109424115193204736" rel="noreferrer">This tweet</a> from the account of the Centro de Investigación Atmosférica de Izaña (AEMET) <a href="http://izana.aemet.es" rel="noreferrer">http://izana.aemet.es</a>  <em>Izaña Atmospheric Research Center (AEMET)</em> shows images of meteorological instruments pointing at the Sun. I recognize the small glass domed instruments in several images and in detail in the first image as <a href="https://en.wikipedia.org/wiki/Pyranometer" rel="noreferrer">Pyranometers</a> based on <a href="https://earthscience.stackexchange.com/a/16479/6031">this excellent and thorough answer</a>.</p>

<p>But what are the long, thin telescope-like cylindrical objects, each on its own articulated pointer to track the Sun? There seems to be a whole series of them in the background in the fourth image.</p>

<p><a href="https://i.sstatic.net/KjLwY.jpg" rel="noreferrer"><img src="https://i.sstatic.net/KjLwY.jpg" alt="enter image description here"></a> <a href="https://i.sstatic.net/S4REg.jpg" rel="noreferrer"><img src="https://i.sstatic.net/S4REg.jpg" alt="enter image description here"></a> </p>

<p><a href="https://i.sstatic.net/GCXU9.jpg" rel="noreferrer"><img src="https://i.sstatic.net/GCXU9.jpg" alt="enter image description here"></a> <a href="https://i.sstatic.net/nl6Iz.jpg" rel="noreferrer"><img src="https://i.sstatic.net/nl6Iz.jpg" alt="enter image description here"></a></p>

CC BY-SA 4.0
2019-04-13T13:36:04.823Z
related: [What are these Gizmos at Mauna Loa Observatory?](https://earthscience.stackexchange.com/q/16478/6031)
uhoh
<meteorology><earth-observation><instrumentation>
What are these Gizmos at Izaña Atmospheric Research Center in Spain?
uhoh
# What are these Gizmos at Izaña Atmospheric Research Center in Spain?

(Asked by: username_0 on 2019-04-13)

[This tweet](https://twitter.com/AEMET_Izana/status/1109424115193204736) from the account of the Centro de Investigación Atmosférica de Izaña (AEMET) <http://izana.aemet.es> *Izaña Atmospheric Research Center (AEMET)* shows images of meteorological instruments pointing at the Sun. I recognize the small glass domed instruments in several images and in detail in the first image as [Pyranometers](https://en.wikipedia.org/wiki/Pyranometer) based on [this excellent and thorough answer](https://earthscience.stackexchange.com/a/16479/6031).

But what are the long, thin telescope-like cylindrical objects, each on its own articulated pointer to track the Sun? There seems to be a whole series of them in the background in the fourth image.

[![enter image description here](https://i.sstatic.net/KjLwY.jpg)](https://i.sstatic.net/KjLwY.jpg) [![enter image description here](https://i.sstatic.net/S4REg.jpg)](https://i.sstatic.net/S4REg.jpg)

[![enter image description here](https://i.sstatic.net/GCXU9.jpg)](https://i.sstatic.net/GCXU9.jpg) [![enter image description here](https://i.sstatic.net/nl6Iz.jpg)](https://i.sstatic.net/nl6Iz.jpg)

**Tags:** meteorology, earth-observation, instrumentation

> **Comments:**
> **username_0**: related: [What are these Gizmos at Mauna Loa Observatory?](https://earthscience.stackexchange.com/q/16478/6031)  

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## 1 answers

### Answer by username_1 on 2019-04-13. Score: 9

Those are Sun/Moon multispectral photometers and ski radiometers. These are instruments that can scan the sky or track the Sun/Moon for direct measurements. They measure light intensity at multiple narrow wavelength bands, and are designed to measure atmospheric aerosols content and characteristics.

The ones in the third image seem to be a [CIMEL CE-138 Sun Sky Lunar Multispectral Photometer](https://www.cimel.fr/?instrument=sun-sky-lunar-multiband-photometer&lang=en) ([specs](http://cimel-wiki.recherche.usherbrooke.ca/cimel/index.php?title=CIMEL_318_-_general_specifications)).

[![enter image description here](https://i.sstatic.net/mBxZ4.png)](https://i.sstatic.net/mBxZ4.png)

There is just a few brands that make these instruments. Others are [Prede](http://www.isac.cnr.it/en/infrastructures/prede-pom-01-radiometer) and [Kipp & Zonen](https://www.kippzonen.es/Download/414/POM-01-POM-02-Sky-Radiometer-and-PGS-100-Sun-Photometer-Brochure). I don't know why they have so many at the AEMET. Perhaps it is some sort of instrumentation investigation, where they are testing different types of photometers or different wavelengths. Or perhaps, as these instruments have a filter wheel inside, each one may have a different set of filters to have higher multispectral resolution.

> **Comments:**
> **username_0**: Thanks for the speedy answer and great sources!  
> **username_1**: @gansub Thanks for spotting that error. It is fixed now.  
> **username_2**: I suspect they are sky radiometers (first line) and just under the photo "no" should be "so"  

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