سال انتشار: ۱۳۸۱

محل انتشار: پنجمین همایش بین المللی سواحل، بنادر و سازه های دریایی

تعداد صفحات: ۱

نویسنده(ها):

reza Javidan – Faculty Member of Indostrial Maleke Ashtar University- Hydrophysic Research Center
Mohammad reza Khosravi – Faculty Member of Indostrial Maleke Ashtar University- Hydrophysic Research Center

چکیده:

One the best modrern method in the ships terrific control science is satellite remote sensing. Satellites generally using sensors which are sensitive to the electromagnetic spectra. This kind of images is lnown as multispectral images. The precision of the images is related to their resolutions. the more resolution the more precision we have in the ship detection and classification algorithm.
The TM (thematic mapper) imageries of the Landsat 4,5 satellites are the base of this research. The images were taken from the strait of Hormoz in Persian Gulf. These kind of image is composed of 7 multispectral bands. The forth band is not so applicable in extraction of the sea characteristics, but the wake of the ship in this band is well detected. At the same time the same time the signal to noise ratio in this band is very well. The third band is also applicable for extracting the ships wake.
In this article at first, the history of ships traffic control using satellite imageries is mentioned. After that, the introduction to possibility theory is discussed. Finally, the method extraction of the ship characteristics using satellite images is discussed as bellow.
1- Discrimination of the sea from the land using threshold method.
2- Amplification of the edges using spatial high pass filter.
3- Omitting of the registered islands by region growing method.
4- Constructing one image by mixing of the remained objects in two bands.
5- Extracting the characteristics of the object such as area, maximum intensity, main axes of the ship and its wakes.
6- Classification of the objects using fuzzy logic and rule based system such as:
R1: If (AREA is HIGH) and (INTENSITY is HIGH) then OBJECT is SHIP
R2: If (AREA is LOW) and (INTENSITY is HIGH) then OBJECT is NOISE
R3: If (AREA is HIGH) and (INTENSITY is HIGH) then OBJECT is NOISE
The result of the experiments was good enough, thet all the ships tested images were detected. Beacause of using wakes in the calculations, if the size of the ship be less than 60m, with no movement, it will be more difficult to extract the ship characteristics by this mathod. but for moving ships, this mathod has a very good results and can be used in a computer program for controlling the traffic of the ships in the ports and various parts of sea like strait of hormoz.