雷达电波环境特性

雷达系统需要在一个特定的环境中工作，而电波环境是雷达工作环境的重要组成部分。电波环境对雷达系统性能既有抑制作用，又有相辅作用。雷达系统的设计、研制、生产、试验和作战应用都要了解电波环境数据和实时状态。本书是《雷达技术丛书》的基础分册之一，其技术是为雷达提供设计所需的大量环境数据，它具有公用性和通用性。本书共6章，主要介绍雷达工作环境条件及雷达电波在其中的传播规律；并给出各种雷达电波环境的描述参数、参数估计方法；各波段雷达电波在各种电波环境中的传播现象、这些现象对雷达性能的影响以及这些影响的描述、估算方法和修正方法。本书附有大量曲线、图表和数据可供实际设计中使用。

第1 章 概论 ····················································································.001
1.1 引言 ····················································································.002
1.1.1 日地空间 ······································································.002
1.1.2 空间电波环境与电磁环境 ·················································.003
1.1.3 电波环境信息 ································································.004
1.2 电波环境信息技术 ··································································.005
1.2.1 电波环境与雷达的关系 ····················································.005
1.2.2 电波环境信息技术学科概要 ··············································.006
1.2.3 电波环境信息技术的应用与发展 ········································.008
1.3 雷达电波频段和雷达电波传播方式··············································.014
1.3.1 雷达电波频段 ································································.014
1.3.2 雷达电波传播方式 ··························································.016
1.3.3 常见各频段雷达的主要特点 ··············································.018
1.4 电波环境对雷达性能的影响 ······················································.021
1.4.1 电波环境各区域特征 ·······················································.022
1.4.2 雷达环境的电波传播效应 ·················································.024
1.4.3 传播效应对雷达的影响 ····················································.027
参考文献 ·····················································································.030
第2 章 地海面及其电波传播特性 ························································.031
2.1 描述地海面传播特性的几个重要概念 ···········································.032
2.1.1 方向图传播因子 ·····························································.032
2.1.2 后向散射系数 ································································.033
2.1.3 几种角度间的关系 ··························································.034
2.2 地海面的介电特性 ··································································.034
2.2.1 纯水的复介电常数 ··························································.035
2.2.2 冰的复介电常数 ·····························································.035
2.2.3 海水的复介电常数 ··························································.037
2.2.4 土壤的复介电常数 ··························································.038
2.2.5 典型地面的电参数 ··························································.040
2.3 地海面的地波传播衰减 ····························································.041
2.3.1 地波传播衰减计算 ··························································.041
2.3.2 均匀光滑球形地面衰减 ····················································.042
2.3.3 粗糙海面附加传播衰减 ····················································.042
2.4 地海面的反射系数 ··································································.061
2.4.1 平面反射系数和透射系数 ·················································.061
2.4.2 地海面的反射系数 ··························································.063
2.4.3 Fresnel 椭球和反射Fresnel 区 ············································.063
2.4.4 扩散因子 ······································································.074
2.4.5 表面粗糙度对反射系数的影响 ···········································.074
2.5 地面及障碍物绕射 ··································································.077
2.5.1 光滑地球表面绕射 ··························································.077
2.5.2 山脊绕射 ······································································.079
2.5.3 圆顶障碍的绕射计算 ·······················································.080
2.5.4 多重障碍绕射 ································································.082
2.6 多径干涉效应 ········································································.083
2.6.1 产生机制 ······································································.083
2.6.2 多径传播的天线方向图因子 ··············································.084
2.6.3 多径干涉效应引起的角度误差 ···········································.086
2.7 植被树林的衰减 ·····································································.088
2.8 地海杂波理论模型 ··································································.088
2.8.1 简单模型 ······································································.089
2.8.2 粗糙表面散射理论模型 ····················································.091
2.8.3 杂波的起伏特性 ·····························································.094
2.9 地海杂波的测量技术 ·······························································.098
2.9.1 测量原理 ······································································.098
2.9.2 测量技术 ······································································.100
2.10 地杂波的测量数据 ·································································.106
2.10.1 典型地形地物的散射系数和模型 ·······································.107
2.10.2 地杂波的统计特性 ·························································.117
2.11 海杂波 ················································································.126
2.11.1 海面状态描述 ·······························································.126
2.11.2 海杂波的一般特性 ·························································.130
2.11.3 实测海杂波散射系数 ······················································.137
2.11.4 海杂波的统计特性 ·························································.140
2.11.5 海杂波的频谱特性 ·························································.148
2.11.6 影响海面杂波特性的其他因素 ··········································.158
2.11.7 短波频段海杂波特性 ······················································.158
2.12 飞鸟昆虫和气象杂波 ······························································.161
2.12.1 飞鸟昆虫杂波 ·······························································.161
2.12.2 气象杂波 ·····································································.162
参考文献 ·····················································································.163
第3 章 对流层及其电波传播特性 ························································.167
3.1 对流层特性 ···········································································.168
3.2 大气无线电气象参数与折射率 ···················································.169
3.2.1 大气折射率的变化 ··························································.170
3.2.2 对流层大气折射率模型 ····················································.177
3.2.3 降雨率分布 ···································································.184
3.2.4 水蒸气含量分布 ·····························································.189
3.3 大气波导 ··············································································.191
3.3.1 大气波导的形成原因 ·······················································.192
3.3.2 大气波导结构和特征 ·······················································.194
3.3.3 中国大气波导出现率及特征量 ···········································.194
3.3.4 全球大气波导出现率及特征量 ···········································.200
3.3.5 大气波导传播条件 ··························································.215
3.3.6 大气波导传播计算方法 ····················································.217
3.3.7 大气波导预报 ································································.225
3.4 对流层顶与临近空间 ·······························································.233
3.4.1 平流层特性 ···································································.233
3.4.2 中间层与低热层特性 ·······················································.239
3.5 对流层电波传播衰减 ·······························································.244
3.5.1 大气气体吸收 ································································.244
3.5.2 水凝物衰减 ···································································.248
3.5.3 云雾、沙尘衰减 ·····························································.253
3.5.4 对流层波导传播损耗 ·······················································.256
3.6 对流层闪烁 ···········································································.258
3.7 大气折射误差修正 ··································································.260
3.7.1 大气折射基本概念 ··························································.260
3.7.2 大气折射误差及修正 ·······················································.265
3.8 无线电气象参数测量技术 ·························································.285
3.8.1 无线电气象参数的接触式测量 ···········································.285
3.8.2 无线电气象参数的遥感探测 ··············································.287
参考文献 ·····················································································.293
第4 章 电离层及其电波传播特性 ························································.297
4.1 电离层概述 ···········································································.298
4.1.1 电离层结构 ···································································.298
4.1.2 电离层的电离源 ·····························································.300
4.1.3 电离层的主要特征参数 ····················································.303
4.1.4 电离层的测量方法 ··························································.310
4.2 电离层特征参数估算 ·······························································.319
4.2.1 E 层参数估算 ·································································.320
4.2.2 F2 层参数估算 ································································.321
4.3 电离层电子浓度剖面模型 ·························································.322
4.3.1 模型种类 ······································································.323
4.3.2 中国典型电离层数据 ·······················································.328
4.4 电离层不均匀性与不规则变化 ···················································.332
4.4.1 Es 层 ···········································································.332
4.4.2 扩展F 层 ······································································.333
4.4.3 电离层行波式扰动 ··························································.334
4.4.4 突然电离层骚扰 ·····························································.334
4.4.5 电离层暴 ······································································.335
4.4.6 极盖吸收与极光吸收 ·······················································.336
4.5 电离层电波传播特性 ·······························································.336
4.5.1 电离层折射指数 ·····························································.336
4.5.2 电离层反射与折射 ··························································.338
4.5.3 电离层法拉第旋转 ··························································.340
4.5.4 电离层色散 ···································································.341
4.5.5 多普勒效应 ···································································.342
4.5.6 电离层传播时延 ·····························································.342
4.6 电离层闪烁 ···········································································.343
4.6.1 闪烁指数 ······································································.344
4.6.2 闪烁信号强度的瞬时分布及功率谱特性 ·······························.345
4.6.3 闪烁全球形态分布及其变化特性 ········································.346
4.6.4 中国、东亚地区电离层闪烁衰落统计 ··································.349
4.7 电离层返回散射传播 ·······························································.351
4.7.1 传播机理与应用 ·····························································.351
4.7.2 返回散射扫频电离图 ·······················································.352
4.7.3 返回散射定频电离图 ·······················································.356
4.7.4 最小时延线 ···································································.359
4.7.5 天波超视距雷达的坐标变换 ··············································.362
4.7.6 返回散射回波能量 ··························································.366
4.8 电离层传播衰减 ·····································································.370
4.8.1 天波雷达路径传播衰减 ····················································.370
4.8.2 穿过电离层的电波传播衰减 ··············································.375
参考文献 ·····················································································.376
第5 章 无线电噪声与干扰 ·································································.379
5.1 无线电噪声与干扰 ··································································.380
5.1.1 无线电噪声 ···································································.380
5.1.2 无线电干扰 ···································································.381
5.1.3 噪声强度及其相关术语 ····················································.381
5.2 0.1Hz～100GHz 范围的Fa 预期值 ···············································.383
5.2.1 0.1 Hz～10 kHz 频段Fa 预期值 ···········································.383
5.2.2 10kHz～100MHz 频段Fa 预期值 ·········································.384
5.2.3 100 MHz～100 GHz 频段Fa 预期值 ·····································.384
5.3 地球表面及其大气层辐射噪声 ···················································.386
5.3.1 晴空大气亮温（噪声） ····················································.386
5.3.2 地球表面亮温 ································································.388
5.4 地球以外的噪声源 ··································································.390
5.4.1 银河系噪声 ···································································.391
5.4.2 天体辐射 ······································································.396
5.5 人为无线电噪声 ·····································································.396
5.5.1 预期值 ·········································································.397
5.5.2 场强与极化 ···································································.399
5.6 大气无线电噪声 ·····································································.399
5.6.1 雷电特性 ······································································.400
5.6.2 预期值 ·········································································.401
5.6.3 中国大气噪声实际测量数据 ··············································.453
5.7 无线电干扰 ···········································································.457
5.7.1 非蓄意干扰 ···································································.457
5.7.2 蓄意干扰 ······································································.458
参考文献 ·····················································································.459
第6 章 电波环境信息的应用 ······························································.460
6.1 电波折射修正的实际应用 ·························································.461
6.1.1 雷达垂直面作用范围图修正 ··············································.461
6.1.2 雷达测量值修正 ·····························································.473
6.2 电波衰减的实际应用 ·······························································.477
6.2.1 雷达最大探测距离修正 ····················································.477
6.2.2 目标回波功率密度计算 ····················································.479
6.2.3 短波地波超视距雷达传播衰减计算 ·····································.480
6.2.4 短波天波超视距雷达传播衰减计算 ·····································.481
6.2.5 超短波雷达传播衰减计算 ·················································.481
6.2.6 微波、毫米波雷达传播衰减计算 ········································.482
6.3 电波环境中雷达性能评估 ·························································.483
6.3.1 大气波导中微波雷达性能评估 ···········································.483
6.3.2 地波超视距雷达电离层污染分析 ········································.490
6.3.3 合成孔径雷达（SAR）电离层影响分析 ································.493
6.3.4 杂波环境中雷达探测性能分析 ···········································.499
6.3.5 探地雷达探测性能分析 ····················································.518
参考文献 ·····················································································.525