İnsansız hava aracı ile anten ışıma diyagramının elde edilmesi
Obtaining radiation diagrams with  unmanned aerial vehicle
Yazar: ERHAN GÜLEÇ
Danışman: YRD. DOÇ. DR. MUSTAFA EMRE AYDEMİR
Hava Harp Okulu Komutanlığı / Havacılık ve Uzay Teknolojileri Enstitüsü / Elektronik Mühendisliği Ana Bilim Dalı / Haberleşme Bilim Dalı
Derece: Yüksek Lisans, 2013
Konu: Elektrik ve Elektronik Mühendisliği = Electrical and Electronics Engineering

Özet:
Bu çalışmanın amacı; mini insansız hava aracıyla anten ışıma diyagramının gerçek ortamda uygulamalı olarak elde edilmesidir. Son yıllarda, havacılıkta kullanılan elektronik sistemlerin maliyetlerinin düşmesi ve performanslarının artmasına bağlı olarak, araştırma merkezleri ve üniversitelerin insansız hava aracı uygulamalarına olan ilgisi artmış ve kendi geliştirdikleri elektronik sistemleri test etmek için küçük boyutlu İHA çalışmaları yapmaya başlamışlardır. Bu çalışmada uzaktan kumandalı ve oto pilot ile uçuş özelliğine sahip, elektrik motorlu insansız hava aracı kullanılarak anten ışıma diyagramının çıkartılması sağlanmıştır.
Antenin ışıma diyagramının çıkarılması için araştırma hedeflerini destekleyecek ve kolaylık sağlayacak en uygun hava  platformunun seçimi için literatür taranmış ve performans incelemeleri yapılmıştır. Ardından mini insansız hava aracı belirlenmiş ve yapımına geçilmiştir. Mini insansız hava aracının belirlenmesinden sonra, yer kontrol istasyonu ile testler esnasında parametrelerin eş zamanlı olarak takip edilmesi ve değiştirebilmesi, uçuş öncesinde ve esnasında uçuş noktalarının belirlemesi, testler esnasında irtifa ve hızın otomatik olarak kontrol edilebilmesi, önceden belirlenen koordinat etrafında dairesel uçuş yapılabilmesi, yer kontrol  istasyonu  sayesinde uçağın  test esnasında ana batarya voltaj durumunun takip edilebilmesi için mini insansız hava aracının uçuşu esnasında oto pilot kullanılmıştır. Ardından 400mhz çıkış gücüne sahip monopol verici anten dikey polarizasyonda uçağa monte edilmiş ve yerde konumlu logaritmik periyodik alıcı anten ve spektrum analizör yardımıyla  yapılan  testler sonucunda uzak alan anten ışıma diyagramı elde edilmiştir.
Öncelikle bu çalışmada, araştırmanın gelecekte de rahatlıkla kullanılabilmesi ve başka araştırmacıların da üzerinde çalışabilmelerini kolaylaştırmak maksadıyla mini insansız hava aracının seçimi ve  yapım aşaması ayrıntılı olarak ele alınmıştır. Mini insansız hava aracında kullanılan oto pilot ve yer sistemi de yine aynı şekilde ayrıntılı olarak  açıklanmıştır.
Bu tez çalışması kapsamında anten ışıma diyagramının oluşumundaki temel kuramsal tanımlar anlatılmıştır. Testlerde kullanılan verici ve alıcı anten  tanıtılmıştır. Uzak alan anten ölçümünde verici antenin uçağa yerleştirilmesi,  alıcı logaritmik periyodik antenin ve spektrum  analizörün  test ortamında nasıl kullanıldığı anlatılmıştır. Anten test sonuçlarının elde edilmesi ile sonuçlar değerlendirilmiştir. Anten ışıma diyagramının  mini insansız hava aracı yardımıyla elde edilebilmesiyle, araştırmacıların bu yöntemi anten ışıma diyagramının çıkartılmasında bir hava platformu yardımıyla yapabileceği ve hâlihazır da kullanılan sistemlerin testlerinde  kullanılabileceği değerlendirilmektedir.

Abstract:
The purpose of this study is to obtain antenna radiation diagram through unmanned air vehicle. To support the research various performance tests were performed to identify the ideal unmanned air vehicle that will yield the most accurate antenna radiation diagrams. 
UAV is the acronym of Unmanned Aerial Vehicle and refers to a class of aircrafts that can fly without the onboard presence of the pilot. They can be flown by an electronic equipment present on the vehicle and at a GCS (Ground Control Station), or directly from the ground. In recent years, electronic systems used in aviation due to the increased costs are reduced. Research centers and universities increased interest in applications of unmanned aerial vehicles and to test the self-developed electronic systems via small-sized unmanned air vehicle. In this study, the autopilot and remote control capable of an unmanned air vehicle are used.
Firstly, the mini-unmanned air vehicle was determined and construction began. According to the task, unmanned air  vehicle needs to carry for the test materials. Unmanned air vehicle must accourding to task needs to reach the required altitude and complete the radius of 50-100 meters task. Easy takeoff and landing capability is required. Unmanned air vehicle must be capable of auto-pilot and remain in the air for the time required by the task. Also it must have a stable flight.
Auto pilot and flight parameters via Ground Control Station was used for testing. Flight points, altitude and the speed was controlled via. these stations. A circular flight around the predetermined coordinate, during flight to follow the status of the main battery voltage of mini-unmanned air vehicle.
Electromagnetic radiation is a form of energy, emitted and absorbed by charged particles which exhibits wave-like behavior as it travels through space. Electromagnetic radiation has both electric and magnetic field components, which stand in a fixed ratio of intensity to each other, and which oscillate in phase perpendicular to each other and perpendicular to the direction of energy and wave propagation. In a vacuum, electromagnetic radiation propagates at a characteristic speed, the speed of light.
Electromagnetic radiation is a particular form of the more general electromagnetic field , which is produced by moving charges. Electromagnetic radiation is associated with electromagnetic fields that are far enough away from the moving charges that produced them, that absorption of the electromagnetic radiation no longer affects the behavior of these moving charges. These two types or behaviors of electromagnetic field are sometimes referred to as the near and far field. In this language, electromagnetic radiation is merely another name for the far-field.  
In general, electromagnetic is classified by wavelength into radio, microwave, infrared, the visible spectrum we perceive as visible light, ultraviolet, X-rays, and gamma rays. Arbitrary electromagnetic waves can always be expressed by Fourier analysis in terms of sinusoidal monochromatic waves, which in turn can each be classified into these regions of the electromagnetic radiation spectrum. 
The polarization of an electromagnetic wave is defined as theorientation of the electric field vector. Recall that the electric field vector is perpendicular to both the direction of travel and the magnetic field vector. The polarization is described by thegeometric figure traced by the electric field vector upon a stationary plane perpendicular to the direction ofpropagation, as the wave travelsthrough that plane. 
An electromagnetic wave is frequently composed of two orthogonal components. This may be due to the arrangement of power input leads to various points on a flat
antenna, or due to an interaction of active elements in an array, or many other reasons. 
An antenna radiation pattern or antenna pattern is de?ned as a mathematical function or a graphical representation of the radiation properties of the antenna as a function of space coordinates.
The beamwidth of an antenna is a very important ?gure of merit and often is used as a trade-off between it and the side lobe level; that is, as the beamwidth decreases, the side lobe increases and vice versa.The beamwidth of the antenna is also used to describe the resolution capabilities of the antenna to distinguish between two adjacent radiating sources or radar targets.
In this study, vertical polarization monopoly transmitter antenna which has 400Mhz output power, then mounted on a plane. With the help of log periodic antenna and spectrum analyzer antenna which situated on the ground, far-field radiation pattern is obtained as a result of the tests.
In this thesis are covered, the selection of the unmanned aerial vehicle, the construction of unmanned aerial vehicle, the methodology of auto-pilot, the basic theoretical formation of the antenna radiation diagrams, the antenna used for transmitting and receiving, the measurement of the far-field antenna, the strategic placement of the transmitting antenna, the use of logarithmic periodic antenna and spectrum analyzer, the gathering and evaluation of antenna test results, the antenna radiation diagrams obtained.
 Primarily in this study, for the other researchers on the study can be handled easily able to work in the future , selection and construction of unmanned aerial vehicle is discussed in detail. Auto-pilot which  is used on the unmanned air vehicle is also described in detail in the same way.In this thesis  the basic theoretical formation of the antenna radiation diagrams are discussed. Transmitting and receiving antenna used in the tests described. 
Measurement of the far-Field antenna how to placed  and  used transmitting antenna on the plane and  how to placed and used  logarithmic periodic antenna and spectrum analyzer  in the test environment. Antenna test results are obtained  and evaluated. Antenna radiation diagrams obtained with the help of mini-unmanned aerial vehicle,  Researchers, with the help of this method, can  use an aerial platform to obtain antenna radiation patern.
Test results can easily be used in future research and other researchers and researchers able to work on the mini-unmanned aerial vehicle used for the measurement of the antenna. Especially very good level of stability is desirable.
Receiving antenna and a logarithmic periodic antenna far-field radiation diagrams can be obtained with the help of the spectrum analyzer. Mini unmanned aerial vehicle?s stability and environmental conditions are the real obstacles. Radiation source signal level is considered to be weak in some areas. Also during the flight regarding a further weakening the stability of mini-unmanned air vehicle is considered to be the wind.
Researchers with the help of this method can get antenna radiation diagram via an aerial platform, are evaluated.