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tech:cloud_sensor [2009/01/27 19:42] matestech:cloud_sensor [Unknown date] (current) – external edit (Unknown date) 127.0.0.1
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 surface and its cloud cover. On the other hand, when the clouds are not present, this condition disappears and the surface radiates into the universe. (Or tries to establish the equilibrium with the cosmic microwave background :-) ) surface and its cloud cover. On the other hand, when the clouds are not present, this condition disappears and the surface radiates into the universe. (Or tries to establish the equilibrium with the cosmic microwave background :-) )
  
-{{ :tech:mrakomer2.jpg?200|The second prototype of Mrakomer (MM-2) in operation at the observatory of OndřejovCZ}}+Of course, this principle works only in nighttime. During the day, Sun provides additional source of radiation and although the signal still can be usedit's interpretation is not straightforward.
  
-**MRAKOMĚR** [[wp>IPA_for_Czech|[mrakomɲer] ]]+=====MRAKOMĚR===== 
  
-Mrakoměr is an Open Hardware” project. After two prototypes, there are two (very similar) versions of the +{{ :tech:mrakomer2.jpg?200|The second prototype of Mrakomer (MM-2) in operation at the observatory of Ondřejov, CZ}} 
 + 
 +Mrakoměr [[wp>IPA_for_Czech|[mrakomɲer] ]] is an [[wp>Open_hardware|Open Hardware]] project. After two prototypes, there are two (very similar) versions of the 
 production devices. As of January 2009, there are 3 units known to be under operation. Furthermore, the second prototype - MM-2, is still operational as well.  production devices. As of January 2009, there are 3 units known to be under operation. Furthermore, the second prototype - MM-2, is still operational as well. 
  
-In the simplest way, this phenomenon was used in the first prototype of Mramomer - MM-1. It uses the Peltier +In the simplest way, this phenomenon was used in the first prototype of Mrakoměr - MM-1. It uses the Peltier 
 cell inserted freely between the earth and the sky. The current generated by the cell is nonzero, and differs significantly when the clouds are present or absent.  cell inserted freely between the earth and the sky. The current generated by the cell is nonzero, and differs significantly when the clouds are present or absent. 
  
 {{:tech:mrakomer3.jpg?200 |The first production sample of MM-3 after a tough night at BOOTES-IR, Sierra Nevada, Spain}} {{:tech:mrakomer3.jpg?200 |The first production sample of MM-3 after a tough night at BOOTES-IR, Sierra Nevada, Spain}}
  
-Further variants of the device use a less straightfordard, but equally effective way of detecting the clouds - measuring the effective temperature of the sky with a solid-state thermopile infrared sensor. Second prototype - MM-2 is a moveable device, able to provide effective temperatures at various inclinacions. The production devices - MM-3 and MM-4, are fixed for simplicity, providing only the temperature in the zenith. MM-4 has, in comparison to MM-3 improved circuitry to provide fault-tolerancy against failure of the sensor, crash of the computer, and burning from lightning.+Further variants of the device use a less straightforward, but equally effective way of detecting the clouds - measuring the effective temperature of the sky with a solid-state thermopile infrared sensor. Second prototype - MM-2 is a movable device, able to provide effective temperatures at various inclinations. The production devices - MM-3 and MM-4, are fixed for simplicity, providing only the temperature in the zenith. MM-4 has, in comparison to MM-3 improved circuitry to provide fault-tolerancy against failure of the sensor, crash of the computer, and burning from lightning.
  
 Software support for Mrakoměr is natively in RTS-2 as a standalone device driver //rts2-sensord-mrakomer// and provides "BAD_WEATHER" signal in case that the readings suggest an overcast situation. Software support for Mrakoměr is natively in RTS-2 as a standalone device driver //rts2-sensord-mrakomer// and provides "BAD_WEATHER" signal in case that the readings suggest an overcast situation.
  
 More about mrakoměr can be found here: [[http://www.mlab.cz/]], More about mrakoměr can be found here: [[http://www.mlab.cz/]],
-description of MM-3 is here: [[http://www.mlab.cz/Designs/MRAKOMER3/DOC/description.pdf]]+description of MM-3 is here: [[http://www.mlab.cz/Designs/MRAKOMER3/DOC/description.pdf]]. Latest version is [[http://www.mlab.cz/Designs/MRAKOMER4/DOC/mrakomer41_en.pdf|MRAKOMĚR 4.1]] is sell by [[http://www.ust.cz/shop/product_info.php?cPath=29&products_id=43|UST]]. 
 + 
 +===== LUNATICO AAGCV3 ===== 
 + 
 +{{ :tech:lunatico_aagcw3.jpg?200|AAGCW3 image taken from the distributors website.}} 
 + 
 +There is a commercial device, designed by [[http://www.aagware.eu/aag_cloudwatcher.htm| António Alberto  Peres Gomes]] and distributed by [[http://www.lunatico.es|Lunatico]], providing cloud sensing (and also light and rain sensing) in a similar way.  
 + 
 +See <code>man rts2-sensor-aag</code>  and [[https://azug.minpet.unibas.ch/wikiobsvermes/index.php/AAG_cloud_sensor| Cloud sensor]] for further documentation abou the device itself.
  
  
tech/cloud_sensor.1233081766.txt.gz · Last modified: 2009/01/27 00:00 (external edit)