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Findclouds Manual   17 

"Desired" resolution. When the masked resolution exceeds the desired resolution, the software will 

scale the image down to desired resolution. Also when there are images with different resolutions 

this can be useful to get normalised images with the same size. When there is no desired size 

given (by empty input) the masked size will be used. 

 

Normal Exposed/ Underexposed 

The extensions to identify images that belong together for high dynamic evaluation by normal exposed and 

underexposed image. This way of evaluation causes a better evaluation of the area near the sun. Please be 

aware not to fill in the separative underscores - they don't belong to the extension. 

 

Latitude / Longitude / Altitude 

These values specify the position of the Sky Imager They are necessary to calculate the position of the sun, 

when evaluating the "near sun area" by underexposed images. When the position is not known, e.g. 

"Google Maps" could be used to find out, where the Cloudcam is placed. 

 

[Mirror],

 when activated, the software mirrors the image when loading it. This changes the "upward 

looking" image to a "ground based image", as if the point of view is changed from ground to above the 

clouds. The new CMS All Sky Imager provides images, that are already mirrored, so this option must be 

deactivated, when "ground based images" are desired and ASI is in use. 

 

[ASI]

 activates a non-linearity equalisation for the new CMS All Sky Imager. While the fisheye Images of the 

Cloudcam follow a strict linear ratio of angle to distance on image, there is a distortion on ASI images, that 

needs to be equalised. 

 

[Choose Photo]

 loads an image made by the current Cloudcam. This image must be used for further 

adjustments and will activate buttons [Center] and [Zenith] when it was loaded successful. 

 

[Angle]

 will switch to adjustment of the Cloudcams offset angle. 

 

[Center]

 will switch back to adjustment of centering and calibration of fisheye area and deactivate 

accentuated contrast. It allows to centre up the image and adjust size of fisheye area. 

 

[Zenith]

 will switch back to adjustment of offset angle and show not equalised image without field of view 

circle. 

 

[Horizon]

 window for input of horizon. 

 

Summary of Contents for ASI-16

Page 1: ...INSTRUCTION MANUAL ASI 16 All Sky Imager Find Clouds Software...

Page 2: ...ow of Findclouds Software 8 2 4 Overview of menu items 10 2 5 Show Curves Display of Cloudiness 11 2 6 Configuration Userinterface 12 2 7 Configuration Cloudcam 14 2 8 Configuration of Evaluation 21 2...

Page 3: ...e appropriate specifications The product warranty is valid only if the product has been installed and used according to the directives provided in this instruction manual CMS shall in no event be liab...

Page 4: ...cluding pictures for additional investigations The cloudiness tells how much the sky is covered with clouds using a number from 0 00 for cloudless sky to 1 00 for completely clouded sky Normally the c...

Page 5: ...df viewer installed and the file extension pdf should be assigned to this viewer 2 1 1 3 Program Files Program files are permanent files that won t be changed after installation except of an update So...

Page 6: ...e creates an additional directory evaluations for the processed images and the text file of evaluated cloudiness The processed images take filename of original file but there are additional extensions...

Page 7: ...uations of several days in the main window table time the time the evaluated photos were shot Ext the merged extensions of the evaluated photos When the evaluation results from one photo with extensio...

Page 8: ...ows This window appears when you insert the install CD to your computer and press Install Program Directory shows the target of installation and Data Directory shows the directory that will be used fo...

Page 9: ...the final installation directory is hard coded for Findclouds So it s a choice of basic directory e g c for installation of c Findclouds or d CMS for installation of d CMS Findclouds 2 2 1 3 Install s...

Page 10: ...stall starts the installation to the shown target directories Uninstall uninstalls the software Update Repair overwrites the existing installation by the current version Close terminates the installat...

Page 11: ...ontrol When there is a different structure by customer the software will use basic data directory for custom directory and show Days out of the basic data directory Be aware that software only reads i...

Page 12: ...defined in configuration e g 0 and 02 the software groups these files and shows them as one but with grouped extensions For evaluation the files can be selected the same way told above for Days browse...

Page 13: ...re are a lot of directories this function may last for some time Imagesize overwrites configuration value of desired image size for current evaluation When this entry is empty the value of the configu...

Page 14: ...le of cloudiness values As a matter of principle the display only shows selected days Showing all days normally would take too much drawing time When at least one display is opened Show Curves the sof...

Page 15: ...ng area e g to show lots of values better Section deals with a special problem When repeating evaluations the results will be appended at the end of the list won t overwrite former evaluations The sof...

Page 16: ...mages Load Evaluations loads existing evaluations to the image list of main dialogue when activated Otherwise this list will show only current evaluations Exclude By Ratio activates an analysis of the...

Page 17: ...the BRBG evaluation as a grayscaled intensity picture where the sky parts are set to zero YYYYMMDDhhmmss_brbg_intens png BRBG Mask causes the software to export the mask that was used to mask out the...

Page 18: ...to a real example Square Resolution The Cloudcam uses a fisheye lens whole sky lens which takes a circular image near the middle of the rectangular photo Because of that both sides of the image are un...

Page 19: ...d Mirror when activated the software mirrors the image when loading it This changes the upward looking image to a ground based image as if the point of view is changed from ground to above the clouds...

Page 20: ...lly the border of the fisheye area is dark and not easy to differentiate from unused black area This way it is easy to see where the real photo ends and a corona begins which doesn t belong to the ima...

Page 21: ...possibility for better adjustment is enlarging the dialog by maximise button or pulling the edges Center will switch back to adjustment of offset angle and deactivate accentuated contrast It allows to...

Page 22: ...the sun moves to the right direction Looking at the screenshot above it is easy to see by the sun pointer that the Cloudcam is not placed in the right direction and an angle offset must be rectified...

Page 23: ...use the sun pointer matches the position of moved sun The arrowhead of sun pointer is not meant to point exact to the middle of the sun and also a little difference in angle won t be a problem because...

Page 24: ...At this point all necessary adjustments are done and the dialog should be left by using Ok button for saving Choose Photo can be used to load another photo for comparison e g to control match of sun...

Page 25: ...er clockwise sets direction of down the list When there is clockwise activated it is necessary to set consecutive horizon points in clockwise direction Going into the wrong direction would switch insi...

Page 26: ...ailed image will be shown by clicking on one of the images This is a copy and will stay when doing a new evaluation so it can be used for comparison to evaluate parameter changes In general it is poss...

Page 27: ...tion of Cloudcam The slider on right hand side of sunmask sets the size of sunmask Three parts of evaluation are using the sunmask Evaluation Sun Pixel always uses the sunmask to restrict the sun pixe...

Page 28: ...e activated The BRBG Algorithm calculates the ratio blue red blue green out of the projected RGB image It shows the result in Colourratio NE and Colourratio UE In reality the result of the three RGB v...

Page 29: ...e adjustment of Bright Pixel The value Cloud Bright Pixel is counted after adjustment of Bright Pixel Now bright pixel caused by haze are not counted as cloud any more This will cause a reduced cloudi...

Page 30: ...CDOC method results out of the fact that bright parts of the Clear Sky Image the area near the sun can not be evaluated because there is no evaluable red blue ratio left by overexposed pixel To handl...

Page 31: ...fied Clear Sky Images ClearSkyJunk txt contains rejected images which are not usable for evaluations Clear Sky New and Junk 1 The choice Clear Sky shows the content of ClearSkyLibrary txt inside of th...

Page 32: ...re required Junk The button moves the selected images to the ClearSkyJunk txt USE The button moves the selected images to the ClearSkyLibrary txt Select The button selects the whole list So there are...

Page 33: ...t track manual changes of csl content When there is no ClearSkyLibrary txt but a csl directory the software will rebuild the ClearSkyLibrary txt using the content of csl directory Cancel OK There are...

Page 34: ...d Object 2 sun cloud covered Example 20130928120000_0 This is an example of an image which is difficult to analyse At first glance there seems to be a visible sun When taking a closer look a small clo...

Page 35: ...ight hand side it is obvious that the sun is much more circle like than the jagged clear sky sun Ratio Brightpix Sunpix Tells about haze or thin clouds in front of the sun On clear sky the ratio is le...

Page 36: ...t is possible to exclude them and improve the evaluation Also it is clear that the evaluation depends on resolution of the image and the options must be adjusted when images are calculated with less r...

Page 37: ...be mapped to concentric circles A real fisheye lens will produce some distortions especially for larger angles There will be aberrations from linear ratio of view angle and image radius But for the mo...

Page 38: ...ng angle will be assigned to a constant image radius R whereby a constant distance a will result for all angles a b tan 90 a b tan 90 By use of the specified values for and R the constant a can be cal...

Page 39: ...nd size of aberration it makes sense to look at the underlying tangent function Especially the derivation of the tangent shows directly the difference between original fisheye lens pixel and resulting...

Page 40: ...mages demonstrate how the image content evolves with zenith angle For 60 projection there are only small gaps that need to be filled For 80 it is clear to see that from half the image radius on large...

Page 41: ...n M Blumthaler All sky imaging a simple versatile system for atmospheric research Applied Optics Vol 48 No 7 1 March 2009 3 M S Ghonima B Urquart C W Chow J E Shields A Cazorla J Kleissl A method for...

Page 42: ...6719 www eko co jp EKO North America 95 South Market Street Suite 300 San Jos CA 95113 USA P 1 408 977 7751 F 1 408 977 7741 www eko eu com EKO Europe Middle East Africa South America Lulofsstraat 55...

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