Apparatus and method for minimizing multipath signal errors during tracking of GPS satellite signals
    1.
    发明授权
    Apparatus and method for minimizing multipath signal errors during tracking of GPS satellite signals 失效
    在GPS卫星信号跟踪期间最小化多径信号误差的装置和方法

    公开(公告)号:US06727846B1

    公开(公告)日:2004-04-27

    申请号:US09666111

    申请日:2000-09-20

    申请人: Alison K. Brown

    发明人: Alison K. Brown

    IPC分类号: G01S502

    CPC分类号: G01S19/22 G01S3/74 G01S19/36

    摘要: A digital GPS receiver includes electronics to detect the presence of multipath GPS signals, determine the direction from which they are received at a multi-element GPS phased array antenna, adaptively generate an antenna pattern to provide gain in the direction of the desired GPS satellite signal, and to apply nulls in the direction of the detected GPS multipath signals. This adaptively-generated antenna pattern is applied to the signals received at the elements of the GPS phased array antenna to provide a composite signal to each of the processing channels of the digital GPS receiver, optimized for the particular GPS satellite being tracked by a corresponding channel. The undesirable multipath GPS signals are thereby excised from the inputs to the processing channels of the digital GPS receiver, and the desired direct signal is reinforced, thus enabling tracking loops within the digital GPS receiver to make highly accurate observations of the code and carrier phase using conventional signal processing techniques.

    摘要翻译: 数字GPS接收机包括用于检测多径GPS信号的存在的电子装置,确定它们在多元素GPS相控阵列天线处的接收方向,自适应地产生天线方向图,以在所需的GPS卫星信号的方向上提供增益 并且在检测到的GPS多路径信号的方向上应用零点。 将这种自适应生成的天线方向图应用于在GPS相控阵天线的元件处接收到的信号,以向数字GPS接收机的每个处理通道提供复合信号,针对由相应信道跟踪的特定GPS卫星进行了优化 。 因此,不期望的多路径GPS信号从数字GPS接收机的处理通道的输入中被切除,并且加强期望的直接信号,从而使得能够在数字GPS接收器内跟踪回路,以使用代码和载波相位的高精度观测来使用 常规信号处理技术。

    Attitude sensing system
    2.
    发明授权
    Attitude sensing system 失效
    姿态感应系统

    公开(公告)号:US4754280A

    公开(公告)日:1988-06-28

    申请号:US416646

    申请日:1982-09-10

    CPC分类号: G01S19/54

    摘要: An attitude sensing system which incorporates the precision in attitude sensing of a satellite navigation system with the dynamic tracking capabilities of an inertial measurement unit. Optimally estimated attitude and system error signals are combined with the outputs of an inertial measurement unit to control the phase differences of signals received on an interferometer array from a navigation satellite. The outputs from the inertial measurement unit and the phase differences are processed in an optimal estimator filter to produce periodically updated attitude and system error signals. This permits inertial attitude sensing to benefit from the long term accuracy of attitude estimation based upon signals from the satellite navigation system. During conditions of high dynamic maneuvering in which attitude changes are rapid, the output of the inertial measurement unit continues to provide attitude information and controls the attitude sensing loop to insure that the system is not disoriented by such high dynamic conditions.

    摘要翻译: 一种姿态感测系统,其将卫星导航系统的姿态感测精度与惯性测量单元的动态跟踪能力相结合。 优化的姿态和系统误差信号与惯性测量单元的输出相结合,以控制从导航卫星在干涉仪阵列上接收的信号的相位差。 惯性测量单元的输出和相位差在最佳估计滤波器中进行处理,以产生周期性更新的姿态和系统误差信号。 这允许惯性姿态感测从基于来自卫星导航系统的信号的姿态估计的长期精度中受益。 在姿态变化快的高动态机动的条件下,惯性测量单元的输出继续提供姿态信息并控制姿态感测回路,以确保系统不被这种高动态条件迷失方向。

    GPS precision approach and landing system for aircraft
    3.
    发明授权
    GPS precision approach and landing system for aircraft 失效
    飞机GPS精准进近系统

    公开(公告)号:US5311194A

    公开(公告)日:1994-05-10

    申请号:US945300

    申请日:1992-09-15

    申请人: Alison K. Brown

    发明人: Alison K. Brown

    CPC分类号: G01S19/11 G01S19/07

    摘要: A GPS precision approach and landing system for aircraft employs a fixed ground facility and a single satellite navigation receiver on board the aircraft. The fixed ground facility includes a reference receiver that measures differential corrections to the satellite code and carrier measurements and a pseudolite that is employed to transmit these corrections to a broadband GPS receiver on board the aircraft and to provide an additional code and carrier measurement to assist in the navigation solution. The pseudolite signal is broadcast at a frequency offset from the L1 GPS frequency in order to prevent interference with the satellite navigation system. The broadband GPS receiver on board the aircraft is capable of making phase coherent measurements from the GPS satellites, the pseudolite signal, and the GLONASS satellites. These phase coherent measurements are combined to form a precise differential carrier ranging (DCR) solution that is used to provide three-dimensional position guidance of the aircraft throughout a precision approach and landing procedure.

    摘要翻译: 用于飞机的GPS精密接近和着陆系统在飞机上使用固定地面设施和单个卫星导航接收机。 固定的地面设施包括一个参考接收机,用于测量对卫星编码和载波测量的差分校正,以及用于将这些校正传输到飞机上的宽带GPS接收机的伪卫星,并提供附加的码和载波测量来协助 导航解决方案。 为了防止与卫星导航系统的干扰,伪卫星信号以与L1 GPS频率偏移的频率广播。 飞机上的宽带GPS接收机能够从GPS卫星,伪卫星信号和GLONASS卫星进行相位相干测量。 这些相位相干测量被组合以形成精确的差分载波范围(DCR)解决方案,其用于在精确进近和着陆过程中提供飞行器的三维位置引导。

    Digital system for codeless phase measurement
    4.
    发明授权
    Digital system for codeless phase measurement 失效
    用于无代码相位测量的数字系统

    公开(公告)号:US4862178A

    公开(公告)日:1989-08-29

    申请号:US211814

    申请日:1988-06-27

    IPC分类号: G01S19/11 G01S5/14

    CPC分类号: G01S19/32 G01S2013/466

    摘要: A codeless digital method and apparatus for obtaining measured phase from a plurality of L2 signal transmissions. An intermediate frequency signal is derived by mixing the L2 transmissions with a local oscillator. That signal is hardlimited and employed to terminate the count of a divide-by-32 counter that is clocked by the local oscillator signal and initiated by a signal in synchronization therewith whose frequency is a fraction of the local oscillator. The state of the counter is applied to a four bit latch. The state of the latch, which effectively discards the most significant bit of the count, provides the measured phase of the L2 transmissions from which position can be obtained by reference to the satellite phase and delta range values derived therefrom.

    Method and apparatus for reducing quantization error in laser gyro test
data through high speed filtering
    5.
    发明授权
    Method and apparatus for reducing quantization error in laser gyro test data through high speed filtering 失效
    用于通过高速滤波减少激光陀螺测试数据中的量化误差的方法和装置

    公开(公告)号:US4634283A

    公开(公告)日:1987-01-06

    申请号:US590111

    申请日:1984-03-19

    IPC分类号: G01C19/66 G01C25/00 G01C19/64

    CPC分类号: G01C19/66 G01C25/00

    摘要: The use of a high speed moving average filter is shown to filter high speed errors, including white noise in angle and quantization errors, from the output data of a ring laser gyro while it is being tested. The filtered data permits investigation of the lower speed, random walk in angle error of the gyro being tested. For best results, several moving average filters are connected in series.

    摘要翻译: 显示使用高速移动平均滤波器来测试来自环形激光陀螺仪的输出数据的高速误差,包括角度上的白噪声和量化误差。 滤波后的数据允许调查正在测试的陀螺仪的较低速度,随机游走角度误差。 为了获得最佳效果,几个移动平均滤波器串联连接。

    Miniature phased array antenna system
    6.
    发明授权
    Miniature phased array antenna system 失效
    微型相控阵天线系统

    公开(公告)号:US06246369B1

    公开(公告)日:2001-06-12

    申请号:US09395550

    申请日:1999-09-14

    IPC分类号: H01Q302

    摘要: A miniature phased array antenna system employs a substrate having a high dielectric constant. A plurality of antenna elements are located on a surface of the substrate, and a superstrate having a high dielectric constant covers the antenna elements. The dielectric constant, thickness, and shape of the superstrate enable it to act as a dielectric lens for controlling the phase relationship of a signal received by the antenna elements. The design of the superstrate dielectric lens permits a reduction in the physical spacing between the antenna elements while maintaining spatial diversity in phase between signals arriving from different directions. Thus, the antenna array may be significantly smaller than conventional phased array antennas while maintaining a similar phase relationship to that achieved using conventional phased array antennas. Electronic circuitry coupled to each of the plurality of antenna elements applies complex weights to received signals prior to a summation thereof in order to reconstruct a desired signal and to deconstruct an undesired signal. SAW filters employed in the electronic circuitry are temperature controlled to maintain group-delay and phase-offset stability.

    摘要翻译: 微型相控阵天线系统采用具有高介电常数的衬底。 多个天线元件位于基板的表面上,并且具有高介电常数的覆盖层覆盖天线元件。 覆盖层的介电常数,厚度和形状使其能够用作用于控制由天线元件接收的信号的相位关系的介电透镜。 上覆电介质透镜的设计允许减少天线元件之间的物理间隔,同时保持从不同方向到达的信号之间的相位的空间分集。 因此,天线阵列可以显着小于常规相控阵列天线,同时保持与使用常规相控阵列天线所达到的相似的相位关系。 耦合到多个天线元件中的每一个的电子电路在其求和之前对接收的信号应用复加权,以便重建期望的信号并解构不期望的信号。 在电子电路中使用的SAW滤波器是温度控制的,以保持组延迟和相位偏移的稳定性。

    Satellite communication system
    7.
    发明授权
    Satellite communication system 失效
    卫星通信系统

    公开(公告)号:US6157621A

    公开(公告)日:2000-12-05

    申请号:US938015

    申请日:1997-09-10

    摘要: The Satellite Communication System disclosed in the specification is a dynamic constellation (C) of satellites (S). The present invention is capable of offering continuous voice, data and video service to customers across the globe on the land, on the sea, or in the air. The preferred embodiment of the invention comprises a low Earth orbit satellite system that includes 40 spacecraft (S) traveling in each of 21 orbital planes at an altitude of 700 km (435 miles). This relatively large number of satellites employed by the preferred embodiment was selected to provide continuous coverage of the Earth's surface at a high minimum mask angle (1230a) of forty degrees. Each of the individual 840 spacecraft (S) functions as an independent sovereign switch of equal rank which knows the position of its neighbors, and independently handles traffic without ground control. The satellites (S) are capable of transporting calls to millions of customers using portable (P), mobile (M) and fixed (F) residential and business terminals, and gateways (G) to public phone networks. The constellation uses the 20 and 30 GHz frequency bands for communications between Earth and the constellation (C), and the 60 GHz band for communicating among the satellites (S). The present invention is designed to support in excess of 2,000,000 simultaneous connections, representing over 20,000,000 users at typical business usage levels, and over 350 billion minutes of use per year. Only a system such as the preferred embodiment, which utilizes 840 satellites at a preferred minimum mask angle of forty degrees, can accomplish these challenging objectives.

    摘要翻译: 本说明书中公开的卫星通信系统是卫星(S)的动态星座(C)。 本发明能够在陆地,海上或空中的全球各地的客户提供连续的语音,数据和视频服务。 本发明的优选实施例包括低地球轨道卫星系统,其包括在高度为700公里(435英里)的21个轨道平面中的每一个中行进的40个航天器(S)。 选择由较佳实施例采用的相对较多数量的卫星以40度的最小掩模角度(1230a)提供对地球表面的连续覆盖。 每个840飞船(S)作为独立的主权交换机,具有相等的等级,它知道其邻居的位置,并且独立地处理没有地面控制的交通。 卫星(S)能够使用便携式(P),移动(M)和固定(F)住宅和商业终端以及网关(G)向公众电话网络传送数百万客户的呼叫。 星座使用20和30 GHz频带进行地球和星座(C)之间的通信,以及60 GHz频段用于在卫星(S)之间进行通信。 本发明旨在支持超过2,000,000个并发连接,在典型业务使用水平上代表超过20,000,000个用户,并且每年使用超过350亿分钟。 只有采用840个优选最小掩模角度为40度的卫星的优选实施例的系统可以实现这些具有挑战性的目标。

    GPS tracking system
    8.
    发明授权
    GPS tracking system 失效
    GPS追踪系统

    公开(公告)号:US5379224A

    公开(公告)日:1995-01-03

    申请号:US800850

    申请日:1991-11-29

    摘要: A low cost tracking system employing satellites of the global positioning system (GPS) is suitable for applications involving radiosondes, sonobuoys, and other objects. The tracking system includes a sensor mounted on each object which digitally samples the GPS satellite signals and records them in a data buffer. The digital samples are then transmitted, at a rate lower than that at which the GPS satellite signals were sampled, over a data telemetry link, interleaved with other telemetry data from the object. The GPS data is processed in a data processing workstation where the position and velocity of the sensor, at the time the data was sampled, is computed. The data buffer in the sensor is periodically refreshed, and the workstation periodically computes the new position and velocity of the sensor. Differential corrections are also provided at the workstation to aid in signal acquisition and to increase the precision of the position fix.

    摘要翻译: 采用全球定位系统(GPS)卫星的低成本跟踪系统适用于涉及无线电探空仪,声波和其他物体的应用。 跟踪系统包括安装在每个物体上的传感器,对GPS卫星信号进行数字采样并将其记录在数据缓冲器中。 然后,数字样本以比GPS卫星信号被采样的速率低的速率通过数据遥测链路传输,与来自对象的其他遥测数据交错。 GPS数据在数据处理工作站中进行处理,其中计算出数据采集时传感器的位置和速度。 定期刷新传感器中的数据缓冲区,工作站周期性地计算传感器的新位置和速度。 工作站还提供差分校正,以帮助信号采集并提高定位精度。

    Vehicle tracking system employing global positioning system (GPS)
satellites
    9.
    发明授权
    Vehicle tracking system employing global positioning system (GPS) satellites 失效
    使用全球定位系统(GPS)卫星的车辆跟踪系统

    公开(公告)号:US5225842A

    公开(公告)日:1993-07-06

    申请号:US697754

    申请日:1991-05-09

    CPC分类号: G01S19/51 G01S5/0009

    摘要: A tracking system employing global positioning system (GPS) satellites provides extremely accurate position, velocity, and time information for vehicles or any other animate or inanimate object within any mobile radio communication system or information system, including those operating in high rise urban areas. The tracking system includes a sensor mounted on each object, a communication link, a workstation, and a GPS reference receiver. The sensor operates autonomously following initialization by an external network management facility to sequence through the visible GPS satellites, making pseudo range and delta range or time difference and frequency difference measurements. No navigation functions are performed by the sensor, thereby permitting significant reductions in the cost thereof. The raw satellite measurements, with relevant timing and status information, are provided to the communication link to be relayed periodically back to the workstation. Differential corrections may also be provided at the workstation to increase the accuracy of the object location determination. In normal operation, three satellite measurements are required to compute the location of the object, but for a short time period a minimum of two satellite measurements are acceptable with time, altitude, and map aiding information being provided by the workstation.