论文总字数：18714字

摘 要

在传统的GNSS应用中，接收机附近的反射天线表面干扰接收到的信号。由此产生了一个新的概念，GNSS发射机连同有处理能力的接收机，GNSS产生的散射信号成为双基地雷达系统。星载GNSS-R观测值为延迟多普勒图（Delay - Doppler Map, DDM)，其生成原理为GNSS卫星信号照射到海面发生散射，不同时延和不同多普勒频移的散射信号在海面上形成相对较小的空间单元。DDM功率为镜面反射点附近的散射区域中各个散射点功率的叠加[^[1]]。星载GNSS-R具有十分广泛的工程应用价值。为了更好地利用星载GNSS-R的延迟多普勒图开展海面遥感探测，需要进行星载观测值的模拟仿真。

本文首先对GNSS-R理论模型进行了深入的了解和分析，然后基于GNSS-R理论模型，开展星载GNSS-R观测值的模拟仿真

文章主要包括的内容有：

1. 分别详尽的阐述了全球卫星导航系统是如何出现的，其在发展中的问题和目前国内外对于GPS的探索进程。

2）GPS卫星的位置坐标计算,并且用MATLAB程序模块实现了GNSS观测值仿真软件开发应用。深入分析Zavorotny和Voronovich提出的GNSS散射模型，海面坡度模型以及反射信号镜面反射点计算模型。

3)基于上述模型，利用MATLAB实现星载GNSS-R观测值的模拟仿真。

关键词： 散射模型 GNSS反射信号 仿真模拟

Development of satellite - borne GNSS-R observation simulation software

ABSTRART

In this paper, spaceborne DDM is generated based on GNSS reflection signals.The generation principle of satellite-borne DDM is that the scattering phenomenon occurs when GNSS satellite signals irradiate the sea surface, and the DDM power is actually the superposition of the power of each scattering point in the scattering area near the specular point (sp).Satellite-borne GNSS receiver has a wide range of engineering application value.

In order to use the delay-dopple map (DDM) of GNSS-R (global navigation satellite system-reflection) to realize the remote sensing detection of sea surface target location, we need to carry out simulation experiments of satellite observation.Firstly, the fuzzy function in DDM should be removed.In traditional GNSS applications, a reflective antenna surface near the receiver interferes with the received signal.This gave rise to a new concept, the GNSS transmitter together with a receiver capable of processing, the scattered signals generated by GNSS become a bistatic radar system.

Here we have carried on the thorough extension and the analysis to this theoretical model.Scattering signals with different time delay and different doppler frequency shift can form relatively small space units on the sea surface.The combination of a GPS transmitter and a GPS delay mapping receiver with a downward antenna can also be considered as a multi-static radar scatterometer.

Simulation results show that we can reconstruct the image of sea surface scattering region from DDM including target, and the target position obtained from the image is consistent with the sea surface target position input in simulation.We used actual data for simulation experiment analysis, and the following conclusions can be obtained:

1) the emergence and development process of global satellite navigation system and the research status at home and abroad are respectively described

2) the conversion mode and specific way of GNSS satellite in different coordinate systems, and the calculation of satellite position coordinates.And the MATLAB program module is used to realize the development and application of GNSS observation simulation software.The characteristics of the reflected signal are studied from the delayed doppler chart of GNSS-R.

3) it can be concluded from specific experiments that it is very necessary to study the reflection signal of GNSS-R.The continuous acquisition of analog signals can effectively improve the parameters of the receiver orbit loop.At the same time, the motion trajectory and positioning mode of GNSS-R satellite are simulated to influence various factors of the receiver to capture reflected signals.To a large extent, it can verify whether the newly generated positioning method can be applied in practical work.This provides many new ideas for practical observation.

目录

第一章 绪论 1

1.1 引言 1

1.2 GNSS-R可用的信号源 1

1.3 卫星定位的误差来源 3

1.4 GNSS-R信号 4

第二章 GNSS-R基本原理 8

2.1 GNSS-R基本几何关系 8

2.2 反射信号的极化特性 8

2.3 GNSS-R散射模型 9

2.4 Woodward模糊度函数 10

2.5 双基雷达截面 11

2.6 海面坡度模型 16

2.7 镜面反射点位置计算 17

第三章 观测值仿真软件开发 20

3.1 仿真系统模块介绍 20

3.2 界面设计 21

3.3 DDM模拟 23

第四章 结论与展望 26

4.1 结论 26

4.2 展望 27

参考文献 28

致谢 30

第一章 绪论

1.1 引言

全球导航卫星系统（Global Navigation Satellite System ,GNSS）不仅为用户提供了导航，定位和精确授时信息，还提供了高度稳定的电磁辐射信号[^[2]]。按照目前的研究过程和结果来讲，由于无线电通讯技术的不断成熟，计算机功能的不断强大，三维空间技术的不断发展，导致GNSS的研究迈向了新的阶梯。基于全球导航卫星系统的微波遥感技术（GNSS-Reflections）具有全天时，全天候，覆盖范围广，多信号源，高时空分辨率等应用优势。GNSS-R是指利用GNSS-R接收机接收经反射物表面反射后的信号，并从这些信号中提取反射面特征的技术[^[3]]。

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