Algorithms
and Methodologies of an Automated Spatial Change Informaiton Extraction
System based on Artificial Neural Networks
Siamak
Khorram and Xiaolong Dai
Funded
by Cray Research, Inc.
Computing resources provided by NC Supercomputing Center
OBJECTIVE
To develop and implement a cost-effective, efficient, and automated
technique for remotely sensed change detection with complete categorical
change information based on artificial neural network algorithms.
APPROACH
The algorithm for an automated land cover change detection system was
developed and implemented based on the current neural network techniques
for multispectral image classification. The suitability of application
of neural networks in change detection and its related network design
considerations unique to change detection were first investigated. A
neural network-based change detection system using the backpropagation
training algorithm was then developed.The experimental results using
multitemporal Landsat Thematic Mapper (TM) imagery of Wilmington, North
Carolina are provided. The results from the neural network method were
compared to that from other change detection techniques.
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Landsat
5 TM FCC Wilmington, NC, Winter 1988
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Landsat
5 TM FCC Wilmington, NC, Winter 1994
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RESULTS
The trained four-layered neural network is able to provide complete
categorical information about the nature of changes and detect land
cover changes with an overall accuracy of 95.6% for a four-class (i.e.,
16 change classes) classification scheme. Findings of this study demonstrated
the potential and advantages of using neural network models in change
detection. This method also holds potential to provide a reliable tool
for effectively integrating multisource remotely sensed data and existing
geographic data. The trained neural network for change detection can
perform change detection on a pixel-by-pixel basis in real-time. Therefore,
this method has implications for real-time operation in local or regional
applications.
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| The change map with
complete land cover changes produced by using the trained neural
network as a feed-forward network. |
Map Legend
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