Extraction of Information from Multispectral and PAN of Landsat Image for Land Use Classification in the Case of Sodozuria Woreda, Wolaita Sodo, Ethiopia

High-resolution and multispectral remote sensing images are an important data source for acquiring geospatial information for a variety of applications. The satellite images at different spectral and spatial resolutions with the aid of image processing techniques can improve the quality of information. More specifically, image fusion is very helpful to extract the spatial information from two images of different spatial and spectral images of same area. The Image fusion techniques are also helpful in providing classification accurately. In order to improve the information contents of the remote sensing satellite images at a specific spatial resolution, the different resolution image fusion techniques like Wavelet, PC and IHS have been used to combine panchromatic and multispectral datasets of Landsat ETM+ for the purpose of information extraction. The image under study has been used to identify existing Land use types and perform supervised classification. It has then been identified that forest land, farm land, bare land and built-up area are the most dominant land uses in the study area. Based on the supervised classification, classification accuracy assessment has indicated that Original image (MS) produced 83.33% overall accuracy and 0.7500 Kappa coefficient, PC fused image produced 91.67% overall accuracy and 0.875 Kappa coefficient, IHS fused image produced 86.67% overall accuracy and 0.800 Kappa coefficient, Wavelet-PC based transformation produced 91.67% overall accuracy  and   0.875 Kappa coefficient and Wavelet-HIS based  transformation produced 98.33% overall accuracy and 0.975 Kappa coefficient. Moreover, Wavelet-HIS based transformation method has produced relatively higher accuracy. Generally, based on the overall accuracy and kappa coefficient, fused images in terms of classification accuracy at the expense of information content perform by far better than the original image.

Multisource and Multitemporal Data Fusion in Remote Sensing

The sharp and recent increase in the availability of data captured by different sensors combined with their considerably heterogeneous natures poses a serious challenge for the effective and efficient processing of remotely sensed data. Such an increase in remote sensing and ancillary datasets, however, opens up the possibility of utilizing multimodal datasets in a joint manner to further improve the performance of the processing approaches with respect to the application at hand. Multisource data fusion has, therefore, received enormous attention from researchers worldwide for a wide variety of applications. Moreover, thanks to the revisit capability of several spaceborne sensors, the integration of the temporal information with the spatial and/or spectral/backscattering information of the remotely sensed data is possible and helps to move from a representation of 2D/3D data to 4D data structures, where the time variable adds new information as well as challenges for the information extraction algorithms. There are a huge number of research works dedicated to multisource and multitemporal data fusion, but the methods for the fusion of different modalities have expanded in different paths according to each research community. This paper brings together the advances of multisource and multitemporal data fusion approaches with respect to different research communities and provides a thorough and discipline-specific starting point for researchers at different levels (i.e., students, researchers, and senior researchers) willing to conduct novel investigations on this challenging topic by supplying sufficient detail and references

JERS-1 SAR and LANDSAT-5 TM image data fusion: An application approach for lithological mapping

Satellite image data fusion is an image processing set of procedures utilise either for image optimisation for visual photointerpretation, or for automated thematic classification with low error rate and high accuracy. Lithological mapping using remote sensing image data relies on the spectral and textural information of the rock units of the area to be mapped. These pieces of information can be derived from Landsat optical TM and JERS-1 SAR images respectively. Prior to extracting such information (spectral and textural) and fusing them together, geometric image co-registration between TM and the SAR, atmospheric correction of the TM, and SAR despeckling are required. In this thesis, an appropriate atmospheric model is developed and implemented utilising the dark pixel subtraction method for atmospheric correction. For SAR despeckling, an efficient new method is also developed to test whether the SAR filter used remove the textural information or not. For image optimisation for visual photointerpretation, a new method of spectral coding of the six bands of the optical TM data is developed. The new spectral coding method is used to produce efficient colour composite with high separability between the spectral classes similar to that if the whole six optical TM bands are used together. This spectral coded colour composite is used as a spectral component, which is then fused with the textural component represented by the despeckled JERS-1 SAR using the fusion tools, including the colour transform and the PCT. The Grey Level Cooccurrence Matrix (GLCM) technique is used to build the textural data set using the speckle filtered JERS-1 SAR data making seven textural GLCM measures. For automated thematic mapping and by the use of both the six TM spectral data and the seven textural GLCM measures, a new method of classification has been developed using the Maximum Likelihood Classifier (MLC). The method is named the sequential maximum likelihood classification and works efficiently by comparison the classified textural pixels, the classified spectral pixels, and the classified textural-spectral pixels, and gives the means of utilising the textural and spectral information for automated lithological mapping