Manyetik yöntemler, Dünya'nın manyetik alanının yönü, eğimi veya yoğunluğu ile ilgili bilgileri elde eder. Dünya yüzeyindeki manyetik alanın yoğunluğu, birincil dünya manyetik alanındaki gözlem noktasının konumunun yanı sıra en yaygın manyetik mineral olan manyetit gibi manyetik malzemenin yerel veya bölgesel varyasyonlarının katkılarının bir fonksiyonudur. Manyetik araştırmaların yorumlanması genellikle anomalilerin onları bilinen diğer jeolojik bilgilerle ilişkilendirerek ileriye doğru modellenmesini veya haritalanmasını içerir. Günümüzde karada ve deniz ortamında yeni nesil dron, gps ve hafif kuantum manyetik sensör teknolojileri sayesinde havadan ve denizden yapılan manyetik çalışmalarda daha hızlı, daha ekonomik ve yüksek çözünürlüklü veriler toplanabilmektedir. Gelişmiş İHA (İnsansız Hava Aracı) ve kuantum teknolojisiyle beraber jeofizik cihazları da gelişmektedir. Manyetik anomali veren yapıların araştırılması son 10 yılda gelişen yüksek teknoloji ile İHA ile havadan manyetik araştırmaları doğurmuştur. İHA ile havadan manyetik yöntemi hızlı ve daha geniş alanların taranmasında son 5 yıldır kullanılan en etkili yöntemler arasında gelmektedir. Özellikle topoğrafyanın çok değiştiği ve arazi şartlarının zor olduğu alanlarda en etkili yöntemdir. Ülkemizde öncelikle metalik maden aramalarında aktif olarak kullanılan bir yöntem olup, son zamanlarda arkeoloji, adli vakalar, eski petrol kuyularının tespiti ile patlamış-patlamamış mühimmat (UXO) aramaları için kullanılan yöntemlerin başında gelmektedir. Araştırma alanın genel jeolojisi kazan deresinin topladığı alüvyonal birimlerden oluşmaktadır. Etrafında ise ayrılmamış karasal kırıntılar, gölsel kireçtaşları, marn, şeyl vb. gibi birimler bulunmaktadır. Sahanın ortasında ise kuzey batı yönünde ASKİ'ye ait su demir boruları bulunmaktadır. Etrafında yüksek gerilimli elektrik hatları geçmektedir. Havadan manyetik araştırma için kullandığımız platform bir DJI M600 Pro model drone ile manyetik sensör olarak Geometrics firmasının MagArrow sezyum optik pompalı manyetometresi, hassas gps verileri için Emlid Reach M2 gps modülü ve dronun sürekli sabit yükseklikte uçması için SkyHub lazer altimetresi kullanılmıştır. Bunlara ek olarak arazide hareket ve enerji sağlamak için ek bir adet 4x4 arazi aracı, jeneratör ve ATV aracı kullanılmıştır. Bir metre yüksekliğinde ve bir metre aralıklı uçuş hatları hazırlanması ve bloklarının planlanması için açık kaynak kodlu QGIS programı, dron uçuşları için SHP Engineering 'in yazılımı olan UgCS programı, verilerin indirilmesinde ve farklı formatlara dönüştürülmesinde Geometrics firmasının paket programı olan Geometrics Survey Manager programı ile veri işleme ve haritalandırma aşamasında ise Amerikan Bentley grup firmasının Seequent adlı yerbilimleri yazılımları üreten firmasına ait Oasis Montaj 9.8 programı ve Google Earth programları kullanılmıştır. Çalışma alanında alınan havadan manyetik veriler sonucu yüksek manyetik anomali gösteren noktalarda 70-75, 90 ve 155 mm uzunluklarında tapasız, kör tapalı, hakiki tapalı mühimmatlar tespit edilmiştir. Farklı derinlikler bulunan 155 mm uzunluğundaki mühimmatların manyetik özellikleri karşılaştırılması sonucu yüzeye daha yakın mühimmatların daha yüksek ve yayvan manyetik anomali verdikleri belirlenmiştir. Bu çalışma sonucunda patlamış ve patlamamış mühimmatların belirlenmesinde dron ile yapılan havadan manyetik verilerinin kullanılması; hem ekonomik ve hız açısından avantajlı olup, gelişen manyetik sensörlerin veri kalitesini arttırması ve yeni teknolojilerin yönteme hızlı şekilde uyarlanması bu yöntemin en yüksek avantajları olup, bu yöntemin yüzeye yakın metalik mayın vb. nesnelerin aramasında ilk kullanılacak yöntem olduğu öngörülmüştür.
Magnetic methods obtain information about the direction, inclination, or intensity of the Earth's magnetic field. The intensity of the magnetic field at the Earth's surface is a function of the location of the observatory in the primary earth magnetic field, as well as the contribution of local or regional variations of the magnetic material, such as magnetite, the most common magnetic mineral. Interpretation of magnetic surveys often involves forward modeling or mapping of anomalies by correlating them with other known geological information. The main field produced by electromagnetic currents in the Earth's outer core accounts for about 98% or more of the geomagnetic field. The highly dynamic outer fields resulting from the interaction of solar plasmas with the core field contribute to most of the rest. The effects superimposed on the principal and outer fields are relatively minor static effects resulting from subsurface magnetization contrasts that are of interest in studies used to help determine compositional, structural and thermal properties, and thus the history of the earth's crust and upper mantle. Relatively simple procedures have been developed for measuring and separating the components of the geomagnetic field, making it perhaps Earth's most measured geophysical method from both aerial and satellite surveys. It involves modeling or mapping it forward by associating it with progress. Since the magnetic method was first used in the seventeenth century to locate buried, highly magnetic iron ore deposits, it has been used for a wide variety of problems related to mapping the ground. II. With the advent of precision air magnetometers during World War II, the use of the method has evolved from focusing largely on local exploration for mineral exploration to a regional tool for mapping the thickness of sedimentary basins and the geological structure and nature of buried crystalline rocks. The subsequent development of atomic (resonance) magnetometers, which can provide several times greater sensitivity than previously developed devices and require no orientation, has expanded and simplified the use of magnetic measurement. The magnetic properties of a substance depend on the type and grain size of the magnetic minerals it contains. There are three main types of magnetism. These are diamagnetism, paramagnetism and ferromagnetism. Ferromagnetic rocks are tried to be detected by geophysical magnetic methods. Earth's magnetic field is not always constant. These are changes that occur at different times. Some of these changes are important in the study of the structure and layers of the earth in applied geophysics. These changes are classified as magnetic storms, diurnal changes, secular changes, westward shift and magnetic reversals. Earth's geomagnetic poles can be thought of as the regions of the magnet where the magnetic field is strongest. Earth's geomagnetic poles are hypothetically located at the center of the Earth, from which the geomagnetic field is roughly calculated. The magnetic poles are the points on the compass where the magnetic needle becomes vertical. They are called geomagnetic north pole and geomagnetic south pole. The geomagnetic poles are represented by a hypothetical model and are not always aligned with the magnetic poles since dynamo currents are not symmetrical. Evidence from the rocks shows geomagnetic poles formed by convection currents as the Earth's core moves. Rocks formed from magma in the depths of the earth erupt as lava from the earth's crust. Many of these rocks contain iron-containing minerals that are formed when the lava cools. Magnetic minerals in the cooling lava align with Earth's magnetic field at the time, leaving a record for Earth's geomagnetic field. The magnetic minerals found in the lava move due to the movement of the geomagnetic poles. Magnetometers determine the direction, strength, or relative change in the magnetic field at a particular location. Magnetometers are also used to calibrate electromagnets and permanent magnets and to determine the magnetization of the material. The first magnetometer was invented in 1833 by Carl Friedrich Gauss, who could measure absolute magnetic density. There are two types of magnetometers. These are vector and scalar magnetometers. Modern magnetometers are deployed at drilling sites, mines, submarines and ships, ground surveys and observatories, rotary and fixed-wing aircraft, balloons, space shuttles, and satellites. In geological applications, geomagnetic surveys are mostly done on land and sea surface, by aircraft at altitudes of up to several kilometers and by satellites at roughly 350-650 km. These applications are capable of directly mapping the relatively shallow subsurface sourced geomagnetic field. It is used for a wide variety of applications, from archaeological and engineering field investigations to the exploration of underground economic resources and the determination of crustal-tectonic features and processes. Today, faster, more economical and high-resolution data can be collected in magnetic studies from air and sea, thanks to new generation drone, GPS and light quantum magnetic sensor technologies in land and sea environment. Along with advanced UAV (Unmanned Aerial Vehicle) and quantum technology, geophysical devices are also developing. Investigation of structures that give magnetic anomalies has given birth to aerial magnetic researches with UAV, with the development of high technology in the last 10 years. Airborne magnetic method with UAV is one of the most effective methods used for the last 5 years in scanning faster and wider areas. It is the most effective method especially in areas where topography changes a lot and terrain conditions are difficult. It is a method that is actively used primarily in metallic mineral exploration in our country, and recently it is one of the leading methods used for archeology, forensic cases, detection of old oil wells, and exploded-unexploded ordnance (UXO) surveys. The general geology of the research area consists of alluvial units collected by the Kazan Stream. It is surrounded by unseparated terrestrial fragments, lacustrine limestones, marl, shale, etc. units such as In the middle of the field, there are water iron pipes belonging to ASKİ in the northwest direction. High voltage power lines run around it. The platform we use for aerial magnetic research is a DJI M600 Pro model drone, with Geometrics company MagArrow cesium optical pump magnetometer as magnetic sensor, Emlid Reach M2 gps module for sensitive gps data, and SkyHub laser altimeter for continuous flying of the drone at constant height. An additional 4x4 off-road vehicle, generator and ATV vehicle were used to provide movement and energy to them in the field. The open source QGIS program for the preparation of one-meter-high and one-meter-spaced flight lines and the planning of their blocks, the UgCS program, which is the software of SHP Engineering for drone flights, the data processing with the Geometrics Survey Manager program, which is the package program of Geometrics for downloading and converting data into different formats. and in the mapping phase, the Oasis Assembly 9.8 program of the American Bentley group company, Seequent, which produces geoscience software, and Google Earth programs were used. After the magnetic data taken with the UAV at 1m intervals in the research area, it was subjected to a few corrections. These are line level correction, micro level correction and heading correction. In the data processing phase, using Oasis Montaj 9.8 software, using classical methods for calculating anomalies, a number of different filters were applied to obtain anomaly maps. First, erroneous values due to drone position, takeoff, landing, smoothing and delay errors between the sensor and the drone were deleted. Finally, the daily variation of Earth's magnetic field values due to solar activity was used to correct the data obtained during the research period. As a result of the magnetic data from the air taken in the study area, the result of the magnetic data obtained in the B4 parcel; Magnetic anomalies greater than 10 nT were detected at points B4-U2-10 and B4-U2-11, and ammunitions numbered UX022-232 and UX022-233 were found at 130 and 70 cm depths at these points, which were later excavated. These ammunition are 90 mm long blind cap artillery shells. When we examine the magnetic anomaly carefully, it is seen that the ammunition numbered UX022-232 coming out of the point B4-U2-10 gives a stronger and more widespread magnetic anomaly because it is more oxidized. Unplugged, blind capped and genuine fused ammunitions in 70-75, 90 and 155 mm lengths were detected at other anomaly points. In this parcel numbered B1, 70, 75, 90 and 155 mm long ammunition were detected, and ammunition with large dimensions, closer to the surface and highly oxidized ammunition, especially 155 mm long ammunition, gave wider magnetic anomalies. At points with high magnetic anomalies, ammunitions with 70-75, 90 and 155 mm lengths, without fuse, with blind fuse, and with genuine fuse were detected. Comparing the magnetic properties of 155 mm long ammunition with different depths, it was determined that ammunition closer to the surface generally gave higher and broader magnetic anomalies. As a result of this study, the use of airborne magnetic data by drone in the determination of exploded and unexploded munitions; It is advantageous both in terms of economy and speed, increasing the data quality of the developing magnetic sensors and the rapid adaptation of new technologies to the method are the highest advantages of this method. It is envisaged that it is the first method to be used in searching for objects.
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