Clouds height classification using texture analysis of meteosat images.

number: 
940
English
department: 
Degree: 
Imprint: 
Physics
Author: 
: Alyaa Hussain Ali
Supervisor: 
Dr.Loay A. George
Dr. Laith A. Al-Ani
year: 
2004
Abstract:

In this study some digital image processing medmdUhne been applied on meteorological satellite images. The satellite (MEIHDSAT-7) takes this meteorological image, for the (D3) region, which The IR2 band and water vapour bands are taken from the "Internet" which offer these types of images the process techniques of the image were carried out. The preparation of computer uses the "Visual Basic Version 6.0" language. The language can provide all the required facilities to match the needs of applying the digital image processing methods. The sources of deformations implied by receiving weather images may due to the effect of weather conditions on the receiving system. A black and white mask has been designed to separate the white region from the image treating these deformations, which include the earth surface. A digital filter was used to improve the subjective quality of receiving the images. The existence of noise was reduced by using an enhancement technique (a median filter and neighborhood average). The segmentation (threshold), was used in order to isolate the clouds region from other features, then the classification process was applied by using the K- mean clustering algorithm. A digital image system was suggested to define the regions of cold and high clouds in these meteorological images and calculate their areas, center coordinates, and their horizontal and vertical extension. A comparison between the position and area of clouds detects in the successive images was utilized to calculate the motion distance of the detected clouds. In order to calculate the geographical locations (i.e. longitude and latitude coordinates), a theoretical treatment was performed to transform the coordinates from image coordinates to longitudes and latitudes. The Kmean method is adopted as an unsupervised classification. This method depends on the initial chosen seeds of cluster. Since, the initial seeds are chosen randomly, the user supply a set of means, or cluster centers in the n- dimensional space. The Kmean cluster has been applied on two bands (IR2 band) and (water vapour band), some calculations are done on these two bands, such as calculating the contrast, gray and temperature. The textural analysis is used where six parameters are calculated from the Co-occurrence matrix. These parameter were inserted in the K-mean. The best classifier feature is the angular second moment. When we use the angular second moment with any textural feature we get a good result of the cloud classification, since the angular second moment gives indication on the cloud homogeneity.