【摘要】：礦產對人類的生產生活至關重要,隨著國民經濟飛速發(fā)展,各行各業(yè)對礦產資源的需求量日益增大。無人機半航空瞬變電磁法是近年來提出的一種新的勘查方式,其采用了地面發(fā)射、空中接收的模式,將地面瞬變電磁的大發(fā)射功率和航空電磁的空中大范圍靈活接收的優(yōu)勢相結合,是一種高效的地球物理勘測方法。因此研發(fā)實用型的半航空瞬變電磁接收機系統(tǒng),對于研究半航空瞬變電磁探測方法、提升我國礦產資源勘查能力、推廣應用于生產實踐具有重要意義。本文依托于國土資源部公益性項目“基于無人機的半航空瞬變電磁勘查技術研究”(項目編號:201311037),分析了半航空瞬變電磁法原理及信號特征,并對基于無人機的半航空瞬變電磁接收機關鍵技術進行研究。首先介紹了半航空瞬變電磁法的研究背景和瞬變電磁接收機的研究現(xiàn)狀;其次,從理論上分析了半航空瞬變電磁信號特征及數(shù)據處理方法;剖析國內外半航空瞬變電磁或瞬變電磁儀器功能,綜合分析半航空瞬變電磁接收機的功能需求和技術指標,研究了GPS同步技術和存儲技術;然后針對半航空瞬變電磁信號的特點,提出了以FPGA和ARM作為邏輯和控制中心的半航空瞬變電磁接收機設計方案;在GPS同步技術的基礎上,通過學習恒溫晶振的漂移特點,設計了基于FPGA和恒溫晶振的高精度秒脈沖同步系統(tǒng);在信號采集上,通過前置低噪聲差分放大器調理線圈傳感器輸出的微弱信號,使用∑-?型結構24位高精度A/D轉換器進行數(shù)據采集;在數(shù)據存儲上,通過ARM控制SD卡存儲采集的數(shù)據,除了存儲瞬變電磁信號數(shù)據外,同時根據后期數(shù)據處理的正反演需求,將GPS時間位置、線圈姿態(tài)和相對高度數(shù)據同步處理打包后存儲。半航空瞬變電磁接收機一般采用連續(xù)采集方式進行數(shù)據采集,并采用本地方式進行數(shù)據存儲。最后,為了驗證接收機的性能,對半航空瞬變電磁接收機的各項性能指標進行測試分析,并進行了野外實驗;通過分析測試結果可知,接收機的GPS同步精度達到100ns,信號的最小分辨率為50μV,接收機初步滿足了采集半航空瞬變電磁信號的需求,但接收機的整體性能仍有待進一步提高。
[Abstract]:With the rapid development of national economy, the demand for mineral resources is increasing day by day. The semi-aeronautical transient electromagnetic method of UAV is a new exploration method proposed in recent years. It adopts the mode of ground launching and receiving in the air. It is an efficient geophysical survey method to combine the large transmitting power of ground transient electromagnetism with the advantage of large range flexible receiving in the air of aeronautical electromagnetic field. Therefore, the development of a practical semi-aeronautical transient electromagnetic receiver system is of great significance for the study of semi-aeronautical transient electromagnetic detection methods, the enhancement of mineral resources exploration capability in China, and the popularization and application in production practice. This paper is based on the public welfare project of Ministry of Land and Resources, "the Research of Semi-Aeronautical transient electromagnetic Prospecting Technology based on UAV" (item number: 201311037), and analyzes the principle and signal characteristics of semi-aeronautical transient electromagnetic method. The key technology of semi-aeronautical transient electromagnetic receiver based on UAV is studied. Firstly, the background of the semi-aeronautical transient electromagnetic method and the research status of the transient electromagnetic receiver are introduced, secondly, the characteristics of the semi-aeronautical transient electromagnetic signal and the data processing method are analyzed theoretically. This paper analyzes the functions of semi-aeronautical transient electromagnetic or transient electromagnetic instruments at home and abroad, synthetically analyzes the functional requirements and technical specifications of semi-aeronautical transient electromagnetic receiver, and studies the synchronization technology and storage technology of GPS. Then, according to the characteristics of semi-aeronautical transient electromagnetic signal, a semi-aeronautical transient electromagnetic receiver with FPGA and ARM as logic and control center is proposed. On the basis of GPS synchronization technology, a high precision second pulse synchronization system based on FPGA and thermostatic crystal oscillator is designed by studying the drift characteristics of thermostatic crystal oscillator. In signal acquisition, a low noise differential amplifier is used to adjust the weak signal output from the coil sensor, using 鈭，

本文編號：2301421