Mathematical modeling of disprersive distortions of the wideband chirp signal during its propogation in the ionospheric radiochannel
Theoretical description of the chirp ionosonde operation has been made. Ionosonde registers spectrum sequence of window received-signal sampling. Mathematical modeling of dispersive distortions of spectra registered has been carried out.
Chirp Ionosonde and Its Application in the Ionospheric Research
We present a review of materials related to a chirp ionosonde and its application in the ionospheric research. The principle of operation of an ionosonde radiating a continuous signal with linear frequency modulation is described. The chirp-ionosonde resolution and gain in the signal-to-noise ratio are estimated. Examples of applying a chirp ionosonde to problems of ionospheric HF-wave propagation are considered. Prospects for ionospheric research on the basis of a network of oblique chirp-sounding paths are discussed.
Texture Feature Extraction of RGB, HSV, YIQ and Dithered Images using GLCM, Wavelet Decomposition Techniques
When changing the format of an image from simple RGB to HSV, YIQ and Dithered image, the characteristics of image also change. In this paper, the similar images in the above formats are retrieved using statistical and structural retrieving techniques i.e. GLCM (Gray Level Co-occurrence Matrix) and Wavelet Decomposition techniques. The best results are coming for dithered, HSV images by using GLCM technique for feature extraction and by using Wavelet decomposition; HSV images are giving the best results. While other formats also give the correct retrieval but from the accuracy point of view, HSV images are retrieved with better accuracy using both techniques.