Description: 这是最新的卫星通信基础理论的Matlab仿真实现，pcma以及信号衰减和延迟的仿真。尽管不是我本人原创，但比较都经典。文件为*.m格式 -This is the latest in satellite communications theoretical basis Matlab Simulation, pcma and signal attenuation and delay in the simulation. Although it was not my original, but more are classics. M *. document format Platform: |
Size: 31985 |
Author:符以长 |
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Description: Global navigation satellite systems have been revolutionising surveying, geodesy, navigation and other position/location sensitive disciplines. However, there are two intrinsic shortcomings in such satellite-based positioning systems: signal attenuation and dependence on the geometric distribution of the satellites. Consequently, the system performance can decrease significantly under some harsh observing conditions. To tackle this problem, some new concepts of positioning with the use of pseudo-satellites have been developed and tested. Pseudo-satellites, also called pseudolites, are ground-based transmitters that can be easily installed wherever they are needed. They therefore offer great flexibility in positioning and navigation applications. Although some initial experimental results are encouraging, there are still some challenging issues that need to be addressed. This paper reviews the historical pseudolite hardware developments and recent progress in pseudolite-based positioning, and discusses the current technical issues. Platform: |
Size: 757629 |
Author:angyangxiang |
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Description: 这是最新的卫星通信基础理论的Matlab仿真实现，pcma以及信号衰减和延迟的仿真。尽管不是我本人原创，但比较都经典。文件为*.m格式 -This is the latest in satellite communications theoretical basis Matlab Simulation, pcma and signal attenuation and delay in the simulation. Although it was not my original, but more are classics. M*. document format Platform: |
Size: 31744 |
Author:符以长 |
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Description: 地面移动卫星信道仿真程序 考虑雨衰 阴影 和多径影响-Land mobile satellite communication channel simulation program to consider the shadow of rain attenuation and multipath effects Platform: |
Size: 1024 |
Author:张晓娟 |
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Description:
由于载体对象的高动态特点，其上装载的GNSS 接收机在捕获信号和跟踪定位上面临很大的挑战，因此致使 GNSS/INS 组合系统的定位效果受到严重影响。本论文以 MEMS IMU/GNSS 超紧组合为研究目标，并以 MEMS IMU 环路辅助的GNSS/INS 紧组合技术为研究重点，深入研究了 MEMS IMU 辅助的 GNSS 信号捕获、MEMS IMU 辅助的 GNSS 信号跟踪、MEMS IMU 辅助的 GNSS/INS 紧组合导航定位算法和基于矢量跟踪结构的 GNSS/INS 超紧组合算法，旨在改善MEMS IMU/GNSS 组合导航系统在卫星信号衰减场合中的性能。
-High dynamic characteristics of the carrier object loaded on GNSS receivers face a lot of challenges in the capture of the signal and track positioning on GNSS/INS positioning effect of the combined system, therefore resulting in severely affected. This thesis, MEMS IMU/GNSS super tight combination of research objectives, and to the MEMS IMU loop auxiliary GNSS/INS tight combination of technology with a focus on in-depth study the MEMS IMU Assisted GNSS signal acquisition, MEMS IMU auxiliary of GNSS signal tracking , the MEMS IMU Assisted GNSS/INS tightly integrated navigation positioning algorithm based on the structure of vector tracking GNSS/INS the super tight combination algorithm, designed to improve the performance of MEMS IMU/GNSS integrated navigation system of the satellite signal attenuation occasions. Platform: |
Size: 22207488 |
Author:LeeYJ |
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Description: 卫星通信链路中的雨衰动态特性分析，在卫星通信中，降雨衰减是非常值得关注的通信损耗，这篇论文讲述了雨衰的特点-The dynamic characteristics of rain attenuation in satellite communication link rain attenuation in satellite communications, communication loss is of great concern, this paper describes the characteristics of the rain attenuation Platform: |
Size: 125952 |
Author:leehom |
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Description: 卫星通信信道链路参数计算与模拟.由于降雨对不同频段下的卫星通信造成不同的衰减，通过计算与模拟卫星通信信 道链路参数，可以设计出可靠性更高的卫星通信系统。-Satellite communication channel link parameter calculation and simulation. Due rainfall in different frequency bands for satellite communications under different attenuation caused by calculation and simulation of satellite communication channel link parameters, you can design a higher reliability of satellite communications systems. Platform: |
Size: 2048 |
Author:claire |
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Description: magnetic field strength, making this approach unsuitable for
deep space missions, and also more suitable for low Earth orbits
as opposed to higher ones like the geosynchronous. The
dependence on the highly variable intensity of Earth’s magnetic
field is also problematic because the attitude control
problem becomes highly nonlinear. It is also impossible to control
attitude in all three axes even if the full three coils are used,
since the torque can be generated only perpendicular to the
Earth’s magnetic field vector (Samir, 2009 Vincent, 2010).
Recently, the possibility of using laser power for space
applications becomes of great interest. There are several
advantages of lasers over other techniques of beamed power
the laser receiver is the solar array, so no new receiver technology
is needed. Moreover, space laser beam suffers a less
amount of atmospheric attenuation also it is safe in use where
it cannot produce damage in the satellite surface (El-saftawy-magnetic field strength, making this approach unsuitable for
deep space missions, and also more suitable for low Earth orbits
as opposed to higher ones like the geosynchronous. The
dependence on the highly variable intensity of Earth’s magnetic
field is also problematic because the attitude control
problem becomes highly nonlinear. It is also impossible to control
attitude in all three axes even if the full three coils are used,
since the torque can be generated only perpendicular to the
Earth’s magnetic field vector (Samir, 2009 Vincent, 2010).
Recently, the possibility of using laser power for space
applications becomes of great interest. There are several
advantages of lasers over other techniques of beamed power
the laser receiver is the solar array, so no new receiver technology
is needed. Moreover, space laser beam suffers a less
amount of atmospheric attenuation also it is safe in use where
it cannot produce damage in the satellite surface (El-saftawy Platform: |
Size: 8199168 |
Author:Punith M |
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Description: 在无线通信体系中,由于开放的通信信道条件,卫星通信系统中通信链路容易受到平均大气条件的影响,尤其是采用Ka波段的高频信号的系统,容易受到降雨造成的雨衰影响,严重影响了系统的有效性和可靠性。(In a wireless communication system, the communication channel open, average atmospheric conditions vulnerable to the communication link in satellite communication system, especially the system of high frequency signal using Ka band, vulnerable to the influence of rain attenuation caused by rainfall, seriously affect the validity and reliability of the system. In digital systems, channel coding is often used to improve reliability, while modulation is used to ensure effectiveness. Low order modulation and large redundancy coding are adopted to improve the reliability.) Platform: |
Size: 70656 |
Author:zdjh-3156
|
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Description: SGP是第一个轨道传播器。它是由希尔顿和库尔曼于1966年开发的，这要归功于Kozai在1959年所做的一项研究工作。它是为绕地球轨道运行的卫星制造的，其中包括轨道周期小于225分钟的卫星。该模型假定偏心率低，并且近地点的高度恒定。
SGP4由肯·克兰福德（Ken Cranford）于1970年开发。它是对之前的传播器的改进，目的是跟踪此时轨道上不断增长的卫星数量。它也用于近地卫星。
SGP8也用于近地卫星，几乎类似于SGP4传播器，但计算方法不同。但是，对于大气和重力效应，它遵循相同的模型。
SDP8是适用于深空效果的SGP8传播器。此外，SGP8和SDP8更好地管理了轨道衰减(SGP is the first orbital propagator. It was developed by Hilton and kurman in 1966, thanks to a study by Kozai in 1959. It is made for satellites orbiting the earth, including those with an orbital period of less than 225 minutes. The model assumes low eccentricity and constant perigee height.
SDP4, developed by hujsak in 1979, is a SGP4 propagator for deep space objects. This includes satellites with orbital periods greater than 225 minutes. For a time period higher than this value, the orbit of the satellite will be interfered by the moon and the sun, as well as by some resonance effects in the 12 and 24-hour orbital periods.
Sgp8 is also used in near earth satellites, almost similar to SGP4 propagator, but the calculation method is different. However, it follows the same model for atmospheric and gravitational effects.
Sdp8 is a sgp8 propagator for deep space effects. In addition, sgp8 and sdp8 better manage orbital attenuation) Platform: |
Size: 1718272 |
Author:DLUhch |
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