Automatic observation of cloudiness: Analysis of all-sky images

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TECO - 2012 |
Brussels (Belgium) |
16-18 October 2012
Automatic observation
of cloudiness: Analysis
of all-sky images
Yézer González1
César López1
Emilio Cuevas2
1. Sieltec Canarias S.L.
3. Izaña Atmospheric Research Center (AEMET) Spain
TECO - 2012 | Brussels (Belgium) | 16-18 October 2012
Cloud cover estimation
- The influence of clouds on Earth´s radiation balance is a key component
of the atmospheric system.
- Cloud monitoring is important for aeronautical purposes and weather
forecast.
- Cloud cover estimation is an
activity traditionally performed
by human observations. These
observations are subject to
subjective errors.
- Poor espacial and temporal
resolution.
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
2
SONA
Automatic System of Cloud Observation
SONA features
- CCD sensor. 640x480 pixels, 8 bit, color response from 400 to 700nm
and monochrome response from 400 to 1000nm.
- Very durable aluminium housing.
- Borosilitate dome.
- Rotating shadow band.
- Cooling/heating system (-10º to +50ºC).
- Fast frame rates (up to 70 fps).
- Adjustable JPEG compressed still-images or live MJPEG streaming video.
- Transfer of images via FTP, RTP or HTTP.
- Camera control via HTTP, XML-RPC, Telnet
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
3
SONA
Automatic System of Cloud Observation
SONAs in Spain
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
4
The site
- SONA has been developed and tested at the Izaña
Atmospheric Observatory (IZO; 28.5ºN 16ºW;
2,400 m a.s.l.)
- IZO is a Global Atmospheric Watch (GAW)
observatory (www.aemet.izana.org) of global
importance with a complete atmospheric
components measurement program.
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
5
Cloud Detection Procedure
Accurate cloud detection and monitoring is a challenge
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
6
Cloud Detection Procedure
Accurate cloud detection and monitoring is a complex problem
(A) Biological neuron. (B) Computer neuron model or perceptron. (C) Multilayer neural network with and
input layer, two hidden neuron layers and a neuron output layer.
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
7
Cloud Detection Procedure
Calibration and training
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
8
Cloud Detection Procedure
Detection
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
9
Cloud Detection Procedure
Image cloud detection in progress…
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
10
Aerosols and Haze
Single photo analysis
Multiphoto analysis
Saharan
dust
More
uncorrelated
inputs
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
11
Aerosols and Haze
Original photo
Single analysis
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
Multiphoto analysis
12
Results
SONA vs. human observations
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
13
Ongoing and Future Activities
Cloud Nowcasting
SONA + photovoltaic system
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
14
Ongoing and Future Activities
Cloud flow determination
Implement last developments of High Resolution Winds Products (Atmospheric
motion vectors -AMVs- from MSG/HRVIS) achieved by NWC SAF.
Goal: perform cloud nowcasting using all sky camera images.
J. García-Pereda
AEMET
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
15
Ongoing and Future Activities
Cloud Nowcasting. NWC SAF products
Cloud Mask
Cloud Type
Cloud Top Height
Cloud Top Pressure
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
16
Ongoing and Future Activities
Cloud base height estimation
Goal: Estimate type of clouds and corresponding solar radiation attenuation coefficients
Two SONA cameras
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
17
Acknowledgements
-SONA project has received a grant from Consejería de
Hacienda, Canary Islands Government, FEDER funds.
-CIAI´s Basic System Unit (Ramón Ramos, Rubén del
Campo, Cándida Hernández, Virgilio Carreño, Fernando
de Ory, Enrique Reyes, Antonio Cruz, Rocío López y
Néstor Castro)
-NWC SAF information for cloud Nowcasting
-Engineers and technicians from SIELTEC
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
18
Thank You
Automatic observation of cloudiness: Analysis of all-sky images
Yézer González, César López and Emilio Cuevas
TECO-2012 | Brussels | 16-18 October 2012
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