Earth and Space Science Essay Example | Topics and Well Written Essays - 2000 words

Earth and Space Science - Essay Example Instruments connected to aircrafts and space based platforms of satellite devises perform the function of remote sensing with the analysis of the electronic data recorded during the emission of such radiation for the establishment of forecast ideas. This is a process involving the transmission of radio waves of different frequency through different zones of the atmosphere, some of whom are absorbents of the radiation with the presence of atmospheric gases such as water vapor, carbon dioxide and ozone (Remote sensing, n.d.). Therefore the areas of electromagnetic spectrum where these gases are present are known as absorption bands. Absorption bands are represented by a low transmission value associated with specific ranges of wavelengths. On the other hand, the electromagnetic spectrum of the atmosphere with little or no absorption of the radiation due to the absence of atmospheric gases is called atmospheric windows. They are transparent to radiation and allow the transmission of spe cific wavelengths to the earth’s surface. The instrumentation of new devices is of great effect with the aviation and weather forecasting as they collect data from the reflections of sunlight from a line-of-sight with an object as well as record the frequency modulations on the basis of presence of carbon dioxide and other gases. ... The essential purpose of this classification is meant for the optimum use of all the brightness levels available in the data. The photo integrated wavelength data are classified into two categories; supervised classification and unsupervised classification. The former is used for extracting quantitative information from remotely sensed photo data in order to separately allocate the available data into different known pixels to produce agent parameters for separate classes of interest. Most scientists use the MLC (maximum likelihood classification) classification with advantage of the mean vectors and multivariate spreads of each class. The effectiveness of supervised classification under MLC depends largely on the reasonable levels of accurate estimation of the mean vector m and the covariance matrix for arriving at each spectral data. The problem posed by this classification tool is that the accuracy of the estimation depletes when the classes are of a multimodal distribution (Liu, n.d.). The other classification model is the unsupervised classification. The basic feature of this classification is its independence to human interface by using some clustering algorithm to classify the image data. This classification model is essential for the identification of the number and location of the unimodal spectral classes on the basis of the image data. MMC or migrated means clustering classifier is the tools used in this model for labeling each pixel to unknown cluster centers with intend to move the pixel form one cluster center to another for accurate analysis of the image (ibid). 3. The radiation used for image analysis of the remote sensing function falls subject to the interaction between electromagnetic radiation and the