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A digital phase coded ground probing radar

机译:数字相位编码地面探测雷达

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摘要

Ground probing short pulse radars are used for relatively shallow (less than 20 meters) subsurface mapping of geologic strata, ice sheets, depths of fresh water bodies and for locating underground utilities. One problem in particular, the ability to map the depth of rivers, is not currently possible because of the limited range capability of short pulse radars. Airborne depth measurement would be of great use in monitoring sedimentation and in planning dredging operations in waterways. Dredging operations in rivers are very expensive and improvements in river depth mapping could result in great cost savings for these programs.;This thesis describes the evolution, design and testing of a new kind of ground probing radar. It uses the pulse compression technique of digital phase coding to achieve both better resolution and range than current commercial ground probing radar systems. The transmitted signal consists of a complementary digital code which is phase modulated onto a sine wave carrier. The received signal is coherently detected to recover the code and digitized with a high speed analog to digital converter. The resulting sequence is then cross-correlated with the transmitted code yielding a close approximation to the desired reflectivity sequence of the ground.;Initial performance of the radar was tested in the laboratory with coaxial cable delays and attenuators to measure time performance and sensitivity. Theoretical calculations and field tests showed a range capability of up to 10 meters (depending on water resistivity) in typical river water, which is sufficient to map most areas where dredging is important.
机译:探地短脉冲雷达用于地质层,冰原,淡水体深度的相对浅(不到20米)地下测绘,以及用于地下设施的定位。由于短脉冲雷达的测距能力有限,目前尤其无法解决河流深度测绘这一问题。机载深度测量将在监测沉积物和规划水道疏dr作业中非常有用。河流中的疏ging操作非常昂贵,改进河流深度图可以为这些程序节省大量成本。;本文介绍了一种新型地面探测雷达的演变,设计和测试。它使用数字相位编码的脉冲压缩技术来实现比当前的商用地面探测雷达系统更好的分辨率和范围。发射的信号由一个互补数字码组成,该数字码被相位调制到正弦波载波上。相干检测接收到的信号以恢复代码,并用高速模数转换器将其数字化。然后,所得的序列与发射的代码互相关,从而与所需的地面反射率序列非常接近。;在实验室中用同轴电缆延迟器和衰减器测试了雷达的初始性能,以测量时间性能和灵敏度。理论计算和现场测试表明,典型河水中的测距能力可达10米(取决于水的电阻率),足以绘制疏dr十分重要的大多数区域的地图。

著录项

  • 作者

    Wills, Robert H.;

  • 作者单位

    Dartmouth College.;

  • 授予单位 Dartmouth College.;
  • 学科 Electrical engineering.
  • 学位 D.E.
  • 年度 1987
  • 页码 117 p.
  • 总页数 117
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

  • 入库时间 2022-08-17 11:50:57

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