Lineer örnekleme yöntemi ile uzaktaki cisimlerin şekillerin,n tespiti
Reconsructing the shapes of the objects based on linear sampling method
Yazar: GÜLÇİN YARIMAY
Danışman: PROF. DR. İBRAHİM AKDUMAN
İstanbul Teknik Üniversitesi / Bilişim Enstitüsü / İletişim Sistemleri Ana Bilim Dalı / Uydu Haberleşmesi ve Uzaktan Algılama Bilim Dalı
Derece: Yüksek Lisans, 2019
Konu: Elektrik ve Elektronik Mühendisliği = Electrical and Electronics Engineering

Özet:
LİNEER ÖRNEKLEME YÖNTEMİ İLE UZAKTAKİ CİSİMLERİN ŞEKİLLERİNİN TESPİTİ
ÖZET
Uzaktan algılama, yeryüzünden belli uzaklıkta, atmosferde veya uzaydaki platformlara yerleştirilmiş ölçüm aletleri aracılığıyla, yeryüzü ve nesneleri hakkında bilgi alma ve bunları analiz etme tekniği, ya da nesnelerle fiziksel temasta bulunmadan herhangi bir uzaklıktan yapılan ölçümlerle nesneler hakkında bilgi edinme bilim ve sanatı olarak ifade edilir. Cisimler hakkında bilgi verebilen bu bilim dalı ilerleyen zamanla beraber bir çok soru işaretine cevap bulmuştur. Geçen bu zaman diliminde, sorulara bulunan cevaplar her ne kadar bilim ve insanlık adına çok yararlı olsalar da, bu cevaplar kendi içlerinde çıkardıkları, kendi soru işaretlerini de gün yüzüne çıkarmaktadırlar. Böylesi gelişen teknoloji ve telekom, uzay, radyo astronomi, navigasyon, konumlandırma ve ölçme, gıda, savunma, tıp ve jeofizik gibi alanlardaki büyük devrimler, bir çok yol ayrımını kendileriyle beraber açığa çıkarmıştır. 
Ulaşılamayan bölgelerdeki cisimler hakkında bilgi edinmek, gerek yukardaki alanları, gerekse daha farklı bir çok alanı kapsayan farklı konularda olan etkisini büyük bir başlık altında topluyor. Kendi içinde bir çok devrim ve gelişime şahit olan bilim, bu konuda da bir çok yöntemi öne sunuyor.
Doğrusal örnekleme yöntemi, zaman harmonik ters saçılmadaki bir engelin şeklini, fiziksel özelliklerin veya saçılan maddenin kopuk bileşenlerinin sayısı hakkında önceden bir bilgi olmadan önceden yapılandırmak için bir yöntemdir. Her halükarda hızlı ve güvenilir bir yöntem olarak sayısal olarak kanıtlanmış olmasına rağmen, bunun neden böyle olduğunu kanıtlayacak bir matematiksel tartışma bulunamamıştır. 
Biz bu tezde, Lineer Örnekleme Yöntemini kullanarak uzaktaki cisimlerin şekillerini tespit ettik. Bu amaçla çok sayıda antenli bir görüntüleme sisteminin önüne çeşitli cisimlerin yerleştirilip bu saçıcılardan saçılan alanı Moment Yöntemi ile hesapladık. Saçılan alana Lineer Örneklenme Yöntemi uygulayarak saçıcıların şekilleri tespit edildi. Elde edilen sonuçlar gösterdi ki Lineer Örnekleme Yöntemi ile saçıcıların şekillerinin uzaktan tespiti gerçekçi koşullar altında dahi başarılabilmektedir.

Abstract:
RECONSTRUCTING THE SHAPES OF THE OBJECTS BASED ON LINEAR SAMPLING METHOD
SUMMARY
Remote sensing is defined as the science and art of acquiring information about objects by measurements made from any distance without physical contact with the objects or by means of measuring instruments and information on the earth and its objects by means of measuring instruments located at platforms, at a certain distance from the earth, in the atmosphere or space.This science, which can give information about the objects, has found answers to many question marks in the course of time.Although the answers to the questions are very useful for science and humanity, these answers bring out their own question marks.The major breakthroughs in such advanced technologies and areas as telecom, space, radio astronomy, navigation, positioning and measurement, food, defense, medicine and geophysics have led to many breaks.
Information on the objects in the unreachable regions, the above areas, or different areas covering a different subject covers the effect of a great title.Science, which witnessed many revolutions and developments in itself, offers many methods in this regard.
The linear sampling method is a method for preconfiguring the shape of an obstacle in the time harmonic inverse scatter without prior knowledge about the physical properties or the number of detached components of the scattered matter. In any case, although it has been numerically proven as a fast and reliable method, no mathematical argument has been found to prove why this is so.
When the literature review is considered, it is seen that various studies have been carried out under the headings of underground detection application, medical applications, military and civil applications with microwave frequency measurements. From this perspective, it was found that qualitative sampling methods used in microwave imaging had the ability to provide reconstruction of the scatter shape by observing the behavior of an indicator function, Linear Sampling method as an example. In many places, the name of the microwave is very consumable in terms of the basis of wavelength in the form of electromagnetic radiation ranging from one millimeter to one meter in the context of frequency; It covers frequencies in the range of 300 Mhz (100 cm) and 300 GHz (0.1 cm). 
The microwave is suitable for wireless transmission of signals with larger bandwidth. Microwave addressing wavelengths shorter than 1 meter is widely used in radar, telephone, satellite communication and navigation applications. Widely used in such fields, microwave dag has come to wide limits and is also used in applications such as food preparation, medical treatments and medical supplies. Suitable for signs with larger bandwidth, Microwaves are in the range of 1 GHz and 40 GHz and are also suitable for wireless data transmission.
Within the scope of microwave field boundaries, ie 300 MHz to 300 GHz, microwave imaging is primarily considered, using electromagnetic (EM) waves in the environment or so-called objects embedded or hidden in the structure for the purpose of evaluation, the literature, radar is an object derived from detection / placement applications. Microwave imaging, which is intended for application and engineering for the purpose of inspection without any disturbance or degradation, is referred to as microwave testing.

Microwave imaging for said application and engineering can be divided into two major classes; these classes are quantitative and qualitative imaging techniques. Quantitative imaging techniques, also known as açılma inverse opening method laştır, solve a nonlinear inverse problem and give the geometrical properties of an imaged object that can be defined as electrical properties such as shape, size and position. This non-linear inverse problem can be transformed into a linear inverse problem by the effect of using Born or skewed Born approaches. In order to clarify the situation, it can convert to an equation of type Mx = y where M and y are known, where x symbolized as the image is unknown. As is well known in the literature, the matrix inversion method can be applied directly in such a case, but the case of said inversion method will be much more difficult, as can be seen if a situation in which the M matrix can be large and dense is considered.
In another context, qualitative microwave imaging methods calculate the qualitative profile, which is also referred to as the reflection function or qualitative image, which represents the object that is stored or hidden in other words. The above-mentioned techniques use approaches to simplify the imaging problem and, after the process of using this approach, use the back propagation, also called back migration, phase compensation, or time reversal, to reconstruct the unknown image profile. Some of the qualitative microwave imaging methods are frequency wave count migration algorithm, SAR (Synthetic Aperature Radar) and GPR (Ground Penetration Radar). A microwave imaging system consists of hardware and software components on a generalized basis. The hardware in these two classes on a generalized basis is the part of data collection from the model being tested. In view of the human body model, which is a model under medical imaging, the main event begins with an emitting antenna transmitting electromagnetic (EM) waves towards the model being tested. Based on the logic of the electromagnetic wave (EM) in the literature, the electromagnetic wave (EM) cannot reflect any wave back if the model is made of homogeneous material or is of infinite dimension. When compared to the surrounding homogeneous environment, the presence of any abnormality with different characteristics such as electric or magnetic may reflect a certain part of the electromagnetic wave (EM). The difference between the characteristics of the mentioned abnormality and the surrounding environment is large and the power of the reflected wave is its own. is directly proportional. This reflection, which has a direct proportion to the medium, can be collected by the same antenna in a monstatically designed system or by a different receiving antenna in bistatic configurations. The work should be distributed to a lesser hollow area, also called a sampling area, in order to increase the cross-spaced resolution of the imaging system. With this step taken to increase the cross-spaced resolution, the interconnection between the antennas located close to one another may reveal the falsity of the signals that are intended to collect. Together with this, this will create confusion of the receiver and transmitter systems. In order to overcome such problems that may open the door to big problems, multiple antennas planned to be used may be replaced by a single scanning antenna. A single scanning antenna will help to solve the problem. In configuring the use of a scanning antenna that closes the problem of multiple antennas, the single scanning antenna scans the entire sampling area, and the data collected by the scanning antenna is mapped to the antenna location coordinates. Essentially, if the antenna is moved with a purpose similar to the principle of SAR (Synthetic Aperature Radar), a synthetic aperture is produced for you. In this case, based on the principle of SAR (Synthetic Aperature Radar), aggregated data, sometimes also referred to as safe input, is sent to the software for processing purposes. Depending on the process algorithm applied, microwave imaging techniques can be classified as quantitative and qualitative. 
Qualitative inverse scattering methods attempt to reconstruct the shapes of targets that cannot be reached from scattered areas without any assumptions about the number of targets or the electrical properties of the targets. These methods have been successfully applied in many subjects such as NDT (Nondestructive Testing), medical imaging or underground imaging.
In this thesis, Linear Sampling Method is used to determine the shape of distant objects. For this purpose, we have calculated the area scattered from these scatterers with Moment Method. Noise was added to the scattered area and linear sampling method was applied to the area. The results showed that the linear sampling method can be achieved even under realistic conditions.