Application of UAV Photogrammetry in Mining Areas

Application of UAV Photogrammetry in Mining Areas: Comparison

Please note this is a comparison between Version 1 by Yuanhao Zhu and Version 3 by Sirius Huang.

The geological environmental damage caused by coal mining has become a hot issue in current research. Especially in the western mining area, the size of the mining working face is large, the mining intensity is high, while the surface movement and deformation are more intense and wider. Therefore, it is necessary to effectively monitor the surface using appropriate means and carrying out research on the overlying strata structure of the stope.煤矿开采造成的地质环境破坏已成为热点问题。特别是在西部矿区，采矿工作面尺寸大，开采强度高，而地表运动和变形更剧烈、更宽。因此，有必要利用适当的手段对地表进行有效监测，并对采场上覆地层结构进行研究。无人机摄影测量在矿区的应用由来已久。

mining subsidence
UAV photogrammetry

1. Introduction简介

As an essential source of coal resources in China, coal mining in the western mining area has caused serious geological and environmental damage problems while meeting energy demands. Especially in recent years, with the rapid development of coal mining technology, large-scale, rapid, and high-intensity mining has become the norm. The mining area is mostly characterized by the continuous mining of multiple large-size (generally 150 m–400 m) adjacent working faces. The law of overlying strata and surface movement caused by mining is more complex than that of a single working face. Moreover, the surface movement and deformation show the characteristics of fast subsidence, large deformation, and wide influence range, which also brings specific difficulties and various challenges to the surface monitoring ^[1].

The monitoring technology of a mining area mainly includes conventional surface monitoring technology, unmanned aerial vehicle (UAV) photogrammetry technology, and 矿区的监测技术主要包括常规地表监测技术、无人机摄影测量技术、InSAR (interferometric synthetic aperture radar) monitoring technology. Among them, conventional surface monitoring technology arranges （干涉合成孔径雷达）监测技术。其中，常规表面监测技术在工作面走向或倾斜的主要部分布置“point–line” observation stations on the main section of the strike or inclination of the working face and carries out conventional measurements such as GNSS (global navigation satellite system), traverse, and/or leveling ^[2]. The observation accuracy of this technology is high点线”观测站，并进行常规测量，例如GNSS（全球导航卫星系统），横向和/或调平[2]。该技术的观察精度高; however it has the disadvantages of high cost, heavy workload, easy damage to measuring points, and ease of being limited by topography. Therefore, meeting the needs of surface damage monitoring for high-intensity and large-scale mining in the western mining area is challenging.但它具有成本高、工作量大、容易损坏测量点、易受地形限制等缺点。因此，满足西部矿区高强度、大规模采矿的地表损伤监测需求具有挑战性。

The application of UAV photogrammetry in mining areas has a long history. This technology was originally used for topographic mapping ^[3]. 无人机摄影测量在矿区的应用由来已久。该技术最初用于地形测绘[3]。D-InSAR (differential interferometric synthetic aperture radar) is a technology that uses the phase information of synthetic aperture radar complex images to obtain surface subsidence information. It has the advantages of monitoring all times of day, over a large area and at high precision. Similarly, the structure of overlying strata is key to clarifying the law and mechanism of mining subsidence. The existing literature has discussed various proposals based on field measurement, numerical simulations, and theoretical analysis.（差分干涉合成孔径雷达）是一种利用合成孔径雷达复杂图像的相位信息获取地表沉降信息的技术。它具有在一天中的所有时间，大面积和高精度监控的优点。同样，上覆地层结构是阐明采矿沉陷规律和机理的关键。现有文献基于现场测量、数值模拟和理论分析对各种建议进行了讨论。

二、无人机摄影测量在矿区的应用

2. UAV Photogrammetry in Mining Areas

In terms of UAV monitoring, relevant scholars have also carried out a number of studies. In previous studies ^[4][5], UAV aerial survey technology was used to obtain 在无人机监测方面，相关学者也开展了多项研究。在以往的研究中[4，5]，利用无人机航测技术获取采煤沉陷区表面DEM (digital elevation model) data on the surface of coal mining subsidence areas, which demonstrates and verifies that the data accuracy could reach to the centimeter level. （数字高程模型）数据，证明并验证了数据精度可以达到厘米级。Paweł et al. ^[6] used UAV photogrammetry technology to monitor the surface discontinuous deformation of the mining area and verified the practicability of the UAV in the domain of mining area monitoring. 等人[6]利用无人机摄影测量技术对矿区表面不连续变形进行监测，验证了无人机在矿区监测领域的实用性。Ge et al. ^[7] used drones to observe the surface of the Tahmoor mining area in New South Wales, Australia, and plotted the subsidence curve of the surface of the mining area. 等人[7]利用无人机观测澳大利亚新南威尔士州塔穆尔矿区的表面，绘制了矿区表面的沉降曲线。Zhou et al. ^[8][9] used the UAV photogrammetry approach to monitor the surface subsidence of a coal mining area, inverted the subsidence prediction parameters, and verified that the accuracy of the subsidence basin was 等[8，9]采用无人机摄影测量方法监测某煤矿区地表沉降，反演沉降预测参数，验证沉降盆地精度为81 mm. 。Puniach et al. ^[10] obtained high等人[10]利用无人机摄影测量法获得了矿区地表变形前后的高分辨率数字正射影像。此外，采用加权归一化互相关算法约束匹配结果，并将得到的水平运动与地面三维激光观测结果进行比较。作者观察到精度可以达到3-resolution digital orthophoto images before and after surface deformation in the mining area using UAV photogrammetry. Furthermore, a weighted, normalized cross-correlation algorithm was used to constrain the matching results, and the obtained horizontal movement was compared with ground 31像素。D laser observations. The authors observed that the accuracy can reach up to 1–2ai等[2]利用无人机技术获取尾矿坝正射影像，监测最大沉降范围在11.0 pixels. Dai et al. ^[11] used UAV technology to obtain orthophoto images of tailings dams and monitored the maximum subsidence range within 0.16 m. However, UAV technology is still limited by factors such as cost and accuracy in mine monitoring.以内。然而，无人机技术仍然受到地雷监测成本和准确性等因素的限制。 In terms of 在D-InSAR monitoring, 监测方面，Gabriel et al. ^[12] first used 等[12]首先利用D-InSAR technology to separate the deformation phase from the terrain phase in the interferometric phase and confirmed that the monitoring accuracy of surface deformation can reach centimeter or even millimeter level. In 技术将干涉相的变形阶段与地形相位分离，证实了表面变形的监测精度可以达到厘米甚至毫米级。1996, 年，Carnec et al. ^[13] first used the 等人[13]首次使用D-InSAR method to monitor the surface subsidence of the mining area near 方法监测Gardanne; the maximum subsidence value obtained was 42 mm, and the root mean square error of monitoring was approximately 附近矿区的地表沉降;得到的最大沉降值为42 mm，监测的均方根误差约为459 mm. Moreover, it was found that the differential SAR interferometry was not suitable for monitoring large gradient deformation areas in a short time. Similarly, Yang et al. ^[14][15][16] monitored the surface deformation caused by mining in the mining area based on monorail 。此外，发现差分SAR干涉测量不适用于短时间内监测大梯度变形区域。同样，Yang等人[14，15，16]基于单轨InSAR, time series 、时间序列InSAR, and the combination of InSAR technology and leveling. The authors verified that the root mean square error was between the predicted surface subsidence value and the InSAR monitoring is 以及InSAR技术与找平相结合的方式监测了矿区采矿引起的地表变形。验证了地表沉降预测值与InSAR监测2.15 cm and analyzed its subsidence law. Zhang et al. ^[17] proposed the fusion of 之间的均方根误差，并分析了其沉降规律。Zhang等人[17]提出将“D-InSAR measurement (space)测量（空间）” and “radon monitoring (ground)” to monitor surface mining cracks in mining areas. However, due to the influence of space–time decoherence, atmospheric delay, and orbital error, 和“氡监测（地面）”相结合，以监测矿区的露天采矿裂缝。然而，由于时空退相干、大气延迟和轨道误差的影响，D-InSAR technology could not reliably obtain the large deformation in the central area of the subsidence basin.技术无法可靠地获得沉降盆地中心区的大变形。 Scholars have made some achievements in the study of overlying strata structure学者在上覆地层结构研究方面取得了一些成果; these proposals and the obtained results are largely related to a single working face and multiple working faces are relatively unexplored. In addition to this shortcoming, all previous studies have collectively shown that there is vertical zoning and horizontal zoning in the mining strata of the working face ^[18]. In terms of rock mechanical structure, cantilever beam theory, pressure arch theory ^[19][20], hinged rock block hypothesis ^[21], and key stratum and voussoir beam theory ^[22][23] are the main contributions. 这些建议和获得的结果主要与单个工作面有关，多个工作面相对未被探索。除了这个缺点之外，之前的所有研究都共同表明，工作面的采矿地层存在垂直分区和水平分区[18]。在岩石力学结构方面，悬臂梁理论、压力拱理论[19，20]、铰链岩块假说[21]和关键地层和伏索尔梁理论[22，23]是主要贡献。Wu et al. ^[24] proposed the supporting plate theory in strip or room-and-pillar mining prediction theory. Aiming at the problem of mining pressure behavior in adjacent mining, 等人[24]在条形或室柱采矿预测理论中提出了支撑板理论。针对相邻采采的开采压力行为问题，Jiang ^[25] proposed four types of overly[25]提出了<>种上覆地层空间结构，即（ing strata spatial structure, i.e., (i) ）θ-shaped, (ii) O-shaped, (iii) S-shaped, and (iv) C-shaped.形、（ii）O形、（iii）S形和（iv）C形。 He et al. ^[26][27] proposed the dynamic evolution process of overlying strata 他等[26，27]提出了上覆地层“OX–-F–T” structure, and provided the mechanical conditions for the instability of key stratum in adjacent goafs. Yang et al. ^[28] studied the stability of a goaf roadway in adjacent working faces of the same coal seam. Based on the key stratum theory and -T”结构的动态演化过程，并为相邻采空区关键地层的不稳定提供了力学条件。Yang等人[28]研究了同一煤层相邻工作面中采空区巷道的稳定性。基于关键地层理论和3DEC numerical simulation, 数值模拟，Yu et al. ^[29] put forward their observations under the conditions of fully mechanized top等人[29]提出了在采深较大的综采顶煤崩落开采条件下的观测结果。作者观察到，随着工作面开采总量的增加，地表在极不充分-不足-coal caving mining with large mining depth. The authors observed that with the increase in the total quantity of working face mining, the surface experiences the breaking form of the key stratum in the extremely insufficient–insufficient–sufficient process, which has a direct impact on surface movement and deformation. 充分过程中经历关键地层的断裂形式，这对地表运动和变形有直接影响。