CN108459331A - The time delay absolute Calibrating Method of multimodal satellite navigation receiver - Google Patents

Abstract

Translated fromChinese

本发明提供了一种多模卫星导航接收机的时延绝对校准方法，首先接收机输出的伪距测量值，然后通过接收机复现1PPS信号从生成到实际输出的延迟，最终得到接收机时延。本发明利用卫星信号模拟器全面校准接收机在不同系统、不同频段、不同伪码下的绝对时延，包括接收通道时延和1PPS链路时延，同时还能够校准接收机在不同参考信号相位差下的时延偏差。这种方法不仅适用于各种类型的接收机，还可应用于导航卫星及综合基带的时延校准。

The invention provides an absolute time delay calibration method of a multi-mode satellite navigation receiver. Firstly, the receiver outputs the pseudorange measurement value, and then reproduces the delay of the 1PPS signal from generation to actual output through the receiver, and finally obtains the time delay of the receiver. delay. The invention utilizes the satellite signal simulator to fully calibrate the absolute time delay of the receiver under different systems, different frequency bands and different pseudo codes, including the receiving channel time delay and 1PPS link time delay, and can also calibrate the receiver in different reference signal phases The time delay deviation under the difference. This method is not only applicable to various types of receivers, but also can be applied to the time delay calibration of navigation satellites and integrated basebands.

Description

Translated fromChinese

多模卫星导航接收机的时延绝对校准方法Delay Absolute Calibration Method for Multi-mode Satellite Navigation Receiver

技术领域technical field

本发明涉及一种多模卫星导航接收机的高精度时延标定方法，尤其是能精确校准接收机在不同系统、不同频段、不同伪码下的绝对时延。The invention relates to a high-precision time-delay calibration method for a multi-mode satellite navigation receiver, in particular, it can accurately calibrate the absolute time-delay of the receiver under different systems, different frequency bands and different pseudo-codes.

背景技术Background technique

接收机的时延校准一直是导航领域的一个难点，目前较为普遍的方法有相对时延校准，通过同源零基线比对的手段获取接收机之间的时延偏差。这种方法虽然操作简单，但只能获得待测接收机与参考接收机的相对时延，且校准误差难以从系统差中分离，主要应用于卫星双向、共视比对等时间传递方面。对于多模卫星导航接收机而言，很多场合(如地面站时差监测、卫星通道零值标定等)需要获得接收机的绝对时延，这是相对时延校准所无法做到的。The time delay calibration of receivers has always been a difficult point in the navigation field. At present, the more common method is relative time delay calibration, and the time delay deviation between receivers is obtained by means of homologous zero baseline comparison. Although this method is simple to operate, it can only obtain the relative delay between the receiver under test and the reference receiver, and it is difficult to separate the calibration error from the system error. It is mainly used in time transfer such as satellite two-way and common-view comparison. For multi-mode satellite navigation receivers, in many occasions (such as ground station time difference monitoring, satellite channel zero value calibration, etc.), it is necessary to obtain the absolute time delay of the receiver, which cannot be achieved by relative time delay calibration.

发明内容Contents of the invention

为了克服现有技术的不足，本发明提供一种多模卫星导航接收机的时延绝对校准方法，利用卫星信号模拟器实现接收机时延的绝对校准，接收机接收卫星信号模拟器发送的导航信号，通过伪距测量和1PPS信号比对综合得到接收机的绝对时延。In order to overcome the deficiencies of the prior art, the present invention provides an absolute calibration method for time delay of a multi-mode satellite navigation receiver, which utilizes a satellite signal simulator to achieve absolute calibration of receiver time delay, and the receiver receives the navigation data sent by the satellite signal simulator. Signal, the absolute time delay of the receiver is obtained through pseudo-range measurement and 1PPS signal comparison.

本发明解决其技术问题所采用的技术方案包括以下步骤：The technical solution adopted by the present invention to solve its technical problems comprises the following steps:

(1)接收机输出的伪距测量值ρ_u＝ρ_s+c·τ_chan+TtC，其中ρ_s为模拟器输出的伪距参考值，c为电波传播速度，τ_chan为接收通道时延，TtC为信号到达接收端的发射时延；(1) The pseudo-range measurement value output by the receiver ρ_u = ρ_s + c τ_chan + TtC, where ρ_s is the pseudo-range reference value output by the simulator, c is the wave propagation speed, and τ_chan is the receiving channel delay , TtC is the transmission delay when the signal arrives at the receiving end;

对于外部有1PPS信号输入的接收机而言，接收通道时延τ_chan＝(ρ_u-ρ_s)/c-TtC；对于外部无1PPS信号输出的接收机而言，接收通道时延τ_chan＝(ρ_u-ρ_s)/c；For a receiver with an external 1PPS signal input, the receiving channel delay τ_chan =(ρ_u -ρ_s )/c-TtC; for a receiver without an external 1PPS signal output, the receiving channel delay τ_chan = (ρ_u -ρ_s )/c;

(2)1PPS链路时延指接收机复现1PPS信号从生成到实际输出的延迟，利用计数器测量模拟器1PPS信号与接收机输出1PPS信号的偏差τ_TIC；接收机跟踪导航信号，解算的钟差t_u-t_s为接收机时间与导航信号零值的偏差，得到1PPS链路时延τ_1PPS＝τ_TIC+(t_u-t_s)-TtC；(2) 1PPS link delay refers to the delay from generation to actual output of the 1PPS signal reproduced by the receiver, using a counter to measure the deviation τ_TIC between the 1PPS signal of the simulator and the 1PPS signal output by the receiver; the receiver tracks the navigation signal, and the calculated The clock difference t_u -t_s is the deviation between the receiver time and the zero value of the navigation signal, and the 1PPS link delay τ_1PPS =τ_TIC +(t_u -t_s )-TtC is obtained;

(3)计算接收机时延τ_REV＝τ_chan+τ_1PPS。(3) Calculate receiver time delay τ_REV =τ_chan +τ_1PPS .

本发明的有益效果是：(1)可以精确校准多模卫星导航接收机在不同导航系统信号体制下的绝对时延；(2)并且能够标较接收机在不同参考信号相位差下的时延偏差；(3)这种方法不仅适用于接收机的时延校准，反过来还可应用于卫星端的时延校准。The beneficial effects of the present invention are: (1) the absolute time delay of the multi-mode satellite navigation receiver under different navigation system signal systems can be calibrated accurately; (2) and the time delay of the receiver under different reference signal phase differences can be compared (3) This method is not only applicable to the delay calibration of the receiver, but also can be applied to the delay calibration of the satellite terminal in turn.

附图说明Description of drawings

图1是模拟器自校准的原理图；Figure 1 is a schematic diagram of the simulator self-calibration;

图2是绝对校准的原理图；Figure 2 is a schematic diagram of absolute calibration;

图3是GPS L1/L2通道时延示意图；Figure 3 is a schematic diagram of GPS L1/L2 channel delay;

图4是GLONASS L1频间偏差示意图；Figure 4 is a schematic diagram of GLONASS L1 inter-frequency deviation;

图5是GPS/GLONASS内部系统偏差示意图；Figure 5 is a schematic diagram of GPS/GLONASS internal system deviation;

图6是1PPS链路时延示意图；Fig. 6 is a schematic diagram of 1PPS link delay;

图7是外部参考信号相位差(TtP)的定义示意图；7 is a schematic diagram of the definition of the external reference signal phase difference (TtP);

图8是不同TtP下的通道时延偏差示意图；FIG. 8 is a schematic diagram of channel delay deviation under different TtPs;

图9是不同TtP下的1PPS链路时延偏差示意图；Fig. 9 is a schematic diagram of 1PPS link delay deviation under different TtPs;

图10是1PPS信号输出链路时延的校准方法示意图。FIG. 10 is a schematic diagram of a method for calibrating time delay of a 1PPS signal output link.

具体实施方式Detailed ways

下面结合附图和实施例对本发明进一步说明，本发明包括但不仅限于下述实施例。The present invention will be further described below in conjunction with the accompanying drawings and embodiments, and the present invention includes but not limited to the following embodiments.

绝对校准前需要对模拟器进行自校准，测量模拟器输出信号到达接收机的时延。待接收机定位成功后，接收机与模拟器输出的伪距测量值计算得到接收机的通道时延，而计数器测量接收机与模拟器输出1PPS信号的时差得到1PPS链路时延，通道时延加上1PPS链路时延就是接收机的绝对时延。同时改变接收机外部参考信号的相位关系，标较接收机在不同参考信号相位差下的时延偏差。上述操作每次只能校准接收机在一种信号类型下的时延，对模拟器输出的信号体制进行调整，多次校准即可得到接收机在不同信号类型下的时延。Before absolute calibration, the simulator needs to be self-calibrated, and the time delay between the output signal of the simulator and the receiver is measured. After the receiver is positioned successfully, the channel delay of the receiver is calculated by calculating the pseudo-range measurement value output by the receiver and the simulator, and the counter measures the time difference between the receiver and the simulator output 1PPS signal to obtain the 1PPS link delay and channel delay Adding 1PPS link delay is the absolute delay of the receiver. At the same time, the phase relationship of the external reference signal of the receiver is changed, and the delay deviation of the receiver under different reference signal phase differences is compared. The above operations can only calibrate the time delay of the receiver under one signal type at a time, adjust the signal system output by the simulator, and perform multiple calibrations to obtain the time delay of the receiver under different signal types.

在图1中，模拟器仅开通1颗卫星，将各通道卫星状态设置成GEO，关闭导航电文和大气层模型，导航信号仅调制伪码与一个频段的载波。考虑模拟器输出信号的功率过低导致示波器无法捕获到真实信号，因此在模拟器输出端串联一个放大器，将功率放大后的导航信号和模拟器1PPS信号分别送入示波器的A，B通道。通过示波器测量模拟器输出信号码相位翻转点相对1PPS信号上升沿的时延(又称TtC：Time-to-Code)，得到模拟器输出信号到达接收机的发射时延TtC，从而完成模拟器的自校准。In Figure 1, the simulator only opens one satellite, sets the satellite status of each channel to GEO, turns off the navigation message and the atmospheric model, and the navigation signal only modulates the pseudo code and the carrier of one frequency band. Considering that the power of the output signal of the simulator is too low, the oscilloscope cannot capture the real signal, so an amplifier is connected in series at the output of the simulator, and the amplified navigation signal and the 1PPS signal of the simulator are respectively sent to the A and B channels of the oscilloscope. Measure the time delay (also known as TtC: Time-to-Code) of the code phase inversion point of the simulator output signal relative to the rising edge of the 1PPS signal by an oscilloscope, and obtain the transmission time delay TtC of the simulator output signal reaching the receiver, thereby completing the simulation of the simulator self-calibration.

在图2中，铷钟为模拟器和接收机提供外部10MHz时钟参考，其中延迟器对输入到接收机的10MHz外部参考信号进行延迟。模拟器将导航信号和1PSS信号输出给接收机，接收机开机前先用示波器完成模拟器自校准，待接收机运行稳定后采集接收机器输出的伪距测量值，并用计数器测量模拟器与接收机输出1PPS信号的时差值。图3至图6分别为某款接收机测试得到的GPS L1/L2通道时延、GLONASS L1频间偏差，GPS/GLONASS内部系统偏差和1PPS链路时延。In Figure 2, the rubidium clock provides an external 10MHz clock reference for the simulator and receiver, and the delayer delays the 10MHz external reference signal input to the receiver. The simulator outputs the navigation signal and 1PSS signal to the receiver. Before the receiver starts up, use the oscilloscope to complete the simulator self-calibration. After the receiver runs stably, collect the pseudo-range measurement value output by the receiving machine, and use the counter to measure the simulator and the receiver. Output the time difference value of 1PPS signal. Figure 3 to Figure 6 respectively show the GPS L1/L2 channel delay, GLONASS L1 inter-frequency deviation, GPS/GLONASS internal system deviation and 1PPS link delay obtained by a certain receiver test.

某些接收机需要接收外部参考1PPS时间信号与10MHz频率信号，由于参考可能不同源、传输电缆延迟等原因的影响，二者会存在相位差，称之为TtP(Time-to-Phase)，TtP会对接收机时延产生影响，如图7所示。在图7中，通过延迟器改变10MHz外部参考信号的相位，标记出到达接收机端的10MHz与1PPS信号相位差(又称TtP：Time-to-Phase)，随后分别记录不同TtP值(0～100ns)状态下接收机的绝对时延，换算得到时延偏差。图8和图9为某款接收机在不同TtP下的通道时延偏差和1PPS链路时延偏差。Some receivers need to receive an external reference 1PPS time signal and a 10MHz frequency signal. Due to the influence of different reference sources and transmission cable delays, there will be a phase difference between the two, which is called TtP (Time-to-Phase), TtP It will have an impact on the receiver delay, as shown in Figure 7. In Figure 7, the phase of the 10MHz external reference signal is changed by the delayer, and the phase difference between the 10MHz and 1PPS signals arriving at the receiver is marked (also known as TtP: Time-to-Phase), and then different TtP values (0-100ns ) state, the absolute time delay of the receiver is converted to obtain the time delay deviation. Figure 8 and Figure 9 show the channel delay deviation and 1PPS link delay deviation of a certain receiver under different TtP.

本发明的具体步骤如下：Concrete steps of the present invention are as follows:

(1)接收机输出的伪距测量值用公式可以表达为：(1) The pseudorange measurement value output by the receiver can be expressed as:

ρ_u＝ρ_s+c·τ_sim+TtC (1)；ρ_u = ρ_s + c τ_sim + TtC (1);

其中ρ_s为模拟器输出的伪距参考值，τ_chan为接收通道时延，TtC为信号到达接收端的发射时延；Among them, ρ_s is the pseudorange reference value output by the simulator, τ_chan is the receiving channel delay, and TtC is the transmission delay when the signal reaches the receiving end;

(2)对于外部有1PPS信号输入的接收机而言，接收机通道时延τ_chan为：(2) For a receiver with an external 1PPS signal input, the receiver channel delay τ_chan is:

τ_chan＝(ρ_u-ρ_s)/c-TtC (2)；τ_chan = (ρ_u - ρ_s )/c - TtC (2);

(3)对于外部无1PPS信号输出的接收机而言，接收机时间驾驭至导航系统时间，与发射时延无关，则接收通道时延为：(3) For a receiver without external 1PPS signal output, the time of the receiver is controlled to the time of the navigation system, which has nothing to do with the transmission delay, and the delay of the receiving channel is:

τ_chan＝(ρ_u-ρ_s)/c (3)；τ_chan = (ρ_u - ρ_s )/c (3);

(4)1PPS链路时延指接收机复现1PPS信号从生成到实际输出的延迟，利用计数器测量模拟器1PPS信号与接收机输出1PPS信号的偏差τ_TIC，计算方法如图10所示。(4) 1PPS link delay refers to the delay from generation to actual output of the 1PPS signal reproduced by the receiver. A counter is used to measure the deviation τ_TIC between the 1PPS signal of the simulator and the 1PPS signal output by the receiver. The calculation method is shown in Figure 10.

接收机跟踪导航信号，解算的钟差(t_u-t_s)实际为接收机时间与导航信号零值的偏差，如果接收机输出的1PPS信号不存在延迟，则τ_TIC+(t_u-t_s)＝TtC，但链路时延τ_1PPS的影响，导致τ_TIC+(t_u-t_s)＞TtC，因此1PPS链路时延为：The receiver tracks the navigation signal, and the calculated clock error (t_u -t_s ) is actually the deviation between the receiver time and the zero value of the navigation signal. If there is no delay in the 1PPS signal output by the receiver, then τ_TIC +(t_u - t_s )=TtC, but the influence of the link delay τ_1PPS leads to τ_TIC +(t_u -t_s )>TtC, so the 1PPS link delay is:

τ_1PPS＝τ_TIC+(t_u-t_s)-TtC (4)；τ_1PPS = τ_TIC +(t_u -t_s )-TtC (4);

(5)将两部分结果相加得到接收机时延τ_REV：(5) Add the two parts of the results to get the receiver time delay τ_REV :

τ_REV＝τ_chan+τ_1PPS (5)。τ_REV = τ_chan + τ_1PPS (5).

Claims (1)

1. a kind of time delay absolute Calibrating Method of multimodal satellite navigation receiver, it is characterised in that include the following steps：

(1) the pseudo-range measurements ρ of receiver output_u=ρ_s+c·τ_chan+ TtC, wherein ρ_sFor simulator output pseudorange reference value,C is radio wave propagation speed, τ_chanFor receiving channel time delay, TtC is the transmitting time delay that signal reaches receiving terminal；

For the receiver that outside has 1PPS signals to input, receiving channel delay, τ_chan=(ρ_u-ρ_s)/c-TtC；For outerFor the receiver that portion is exported without 1PPS signals, receiving channel delay, τ_chan=(ρ_u-ρ_s)/c；

(2) 1PPS chain-circuit time delays refer to receiver reproduction 1PPS signals from the delay for being generated to reality output, utilize counter measuresThe deviation τ of simulator 1PPS signals and receiver output 1PPS signals_TIC；Receiver tracking navigation signal, the clock correction t of resolving_u-t_sFor the deviation of receiver time and navigation signal zero, 1PPS chain-circuit time delays τ is obtained_1PPS=τ_TIC+(t_u-t_s)-TtC；

(3) receiver delay, τ is calculated_REV=τ_chan+τ_1PPS。