CN108459331A

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

Info

Publication number: CN108459331A
Application number: CN201810256745.2A
Authority: CN
Inventors: 朱峰; 张慧君; 李孝辉; 黄璐希; 许龙霞
Original assignee: National Time Service Center of CAS
Current assignee: National Time Service Center of CAS
Priority date: 2018-03-27
Filing date: 2018-03-27
Publication date: 2018-08-28
Anticipated expiration: 2038-03-27
Also published as: CN108459331B

Abstract

The present invention provides a kind of time delay absolute Calibrating Methods of multimodal satellite navigation receiver, the first pseudo-range measurements of receiver output, then reappear 1PPS signals from the delay for being generated to reality output by receiver, finally obtain receiver time delay.Absolute time delay of the present invention using satellite signal simulator general calibration receiver under different system, different frequency range, different pseudo-codes, including receiving channel time delay and 1PPS chain-circuit time delays, while time-delay deviation of the receiver under different reference signal phase differences can also be calibrated.This method is applicable not only to various types of receivers, applies also for the time-delay calibration of navigation satellite and synthetical baseband.

Description

The time delay absolute Calibrating Method of multimodal satellite navigation receiver

Technical field

The present invention relates to a kind of high-precision time-delay scaling methods of multimodal satellite navigation receiver, especially can accurate calibration Absolute time delay of the receiver under different system, different frequency range, different pseudo-codes.

Background technology

The time-delay calibration of receiver is always a difficult point of navigation field, and more universal method has relative time delay at present Calibration obtains the time-delay deviation between receiver by the means that homologous zero base line compares.This method is although easy to operate, but The relative time delay of receiver and reference receiver to be measured can only be obtained, and calibration error is difficult to detach from System level gray correlation, mainly answers In terms of the Time Transmissions such as, common-view mode two-way for satellite.For multimodal satellite navigation receiver, many occasions are (as The monitoring of the face station time difference, the calibration of satellite channel zero etc.) it needs to obtain the absolute time delay of receiver, this is relative time delay calibration institute nothing What method was accomplished.

Invention content

For overcome the deficiencies in the prior art, the present invention provides a kind of time delay absolute calibration of multimodal satellite navigation receiver Method realizes that the absolute calibration of receiver time delay, receiver receive satellite signal simulator and send using satellite signal simulator Navigation signal, integrate to obtain the absolute time delay of receiver by pseudo range measurement and 1PPS signal fusings.

The technical solution adopted by the present invention to solve the technical problems includes the following steps：

(1) the pseudo-range measurements ρ of receiver output_u=ρ_s+c·τ_chan+ TtC, wherein ρ_sFor the pseudorange ginseng of simulator output Value is examined, 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；It is right For the receiver that outside 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 Measure the deviation τ of simulator 1PPS signals and receiver output 1PPS signals_TIC；Receiver tracking navigation signal, the clock correction of resolving t_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。

The beneficial effects of the invention are as follows：(1) can be believed in different navigation system with accurate calibration multimodal satellite navigation receiver Absolute time delay under number system；(2) and the time-delay deviation compared with receiver under different reference signal phase differences can be marked；(3) This method is applicable not only to the time-delay calibration of receiver, applies also for the time-delay calibration of satellite end in turn.

Description of the drawings

Fig. 1 is the self-alignment schematic diagram of simulator；

Fig. 2 is the schematic diagram of absolute calibration；

Fig. 3 is GPS L1/L2 channel time delay schematic diagrames；

Fig. 4 is GLONASS L1 inter-frequency deviation schematic diagrames；

Fig. 5 is GPS/GLONASS built-in system deviation schematic diagrames；

Fig. 6 is 1PPS chain-circuit time delay schematic diagrames；

Fig. 7 is the definition schematic diagram of external reference signal phase difference (TtP)；

Fig. 8 is the channel time delay deviation schematic diagram under different TtP；

Fig. 9 is the 1PPS chain-circuit time delay deviation schematic diagrames under different TtP；

Figure 10 is the calibration method schematic diagram of 1PPS signal output link time delays.

Specific implementation mode

Present invention will be further explained below with reference to the attached drawings and examples, and the present invention includes but are not limited to following implementations Example.

It needs to carry out self calibration to simulator before absolute calibration, measures the time delay that simulator output signal reaches receiver. After machine to be received positions successfully, the channel time delay of receiver is calculated in the pseudo-range measurements of receiver and simulator output, and Counter measures receiver and the time difference of simulator output 1PPS signals obtain 1PPS chain-circuit time delays, and channel time delay adds 1PPS chains Road time delay is exactly the absolute time delay of receiver.The phase relation of receiver external reference signal is changed simultaneously, mark exists compared with receiver Time-delay deviation under different reference signal phase differences.Aforesaid operations can only calibrate every time receiver under a kind of signal type when Prolong, to simulator output signal system be adjusted, repeatedly calibration can be obtained receiver under unlike signal type when Prolong.

In Fig. 1, simulator only opens 1 satellite, and each channel satellitosis is arranged to GEO, close navigation message and Atmospheric model, navigation signal only modulate the carrier wave of pseudo-code and a frequency range.Consider that the power of simulator output signal is too low to lead Cause oscillograph that can not capture actual signal, therefore in simulator output end one amplifier of series connection, by leading after power amplification Boat signal and simulator 1PPS signals are respectively fed to the A of oscillograph, channel B.Pass through oscilloscope measurement simulator output signal code Time delay (also known as TtC of the phase bit flipping point with respect to 1PPS signal rising edges：Time-to-Code), simulator is obtained to output signals to Up to the transmitting time delay TtC of receiver, to complete the self calibration of simulator.

In fig. 2, rubidium clock provides external 10MHz clock references for simulator and receiver, and wherein delayer is to being input to The 10MHz external reference signals of receiver are postponed.Simulator exports navigation signal and 1PSS signals to receiver, receives Simulator self calibration first is completed with oscillograph before machine booting, the pseudorange of acquisition reception machine output is surveyed after machine to be received is stable Magnitude is used in combination counter measures simulator to export the time difference value of 1PPS signals with receiver.Fig. 3 to Fig. 6 is respectively that certain money receives GPS L1/L2 channel time delay that machine is tested, GLONASS L1 inter-frequency deviations, GPS/GLONASS built-in systems deviation and 1PPS chain-circuit time delays.

Certain receivers need to receive external reference 1PPS time signals and 10MHz frequency signals, since reference may not The influence of the reasons such as homologous, transmission cable delay, the two can have phase difference, referred to as TtP (Time-to-Phase), TtP meetings Receiver time delay is had an impact, as shown in Figure 7.In the figure 7, change the phase of 10MHz external reference signals by delayer, Mark 10MHz and 1PPS signal phase difference (the also known as TtP for reaching receiver end：Time-to-Phase), then record respectively The absolute time delay of receiver under different TtP values (0~100ns) states, conversion obtain time-delay deviation.Fig. 8 and Fig. 9 receives for certain money Channel time delay deviation and 1PPS chain-circuit time delay deviation of the machine at different TtP.

The present invention is as follows：

(1) pseudo-range measurements of receiver output can be expressed as with formula：

ρ_u=ρ_s+c·τ_sim+TtC (1)；

Wherein ρ_sFor the pseudorange reference value of simulator output, τ_chanFor receiving channel time delay, TtC is that signal reaches receiving terminal Transmitting time delay；

(2) for the receiver that outside has 1PPS signals to input, receiver channel delay, τ_chanFor：

τ_chan=(ρ_u-ρ_s)/c-TtC (2)；

(3) for the receiver that outside is exported without 1PPS signals, receiver time was controlled to the navigation system time, with Transmitting time delay is unrelated, then receiving channel time delay is：

τ_chan=(ρ_u-ρ_s)/c (3)；

(4) 1PPS chain-circuit time delays refer to receiver reproduction 1PPS signals from the delay for being generated to reality output, utilize counter Measure the deviation τ of simulator 1PPS signals and receiver output 1PPS signals_TIC, computational methods are as shown in Figure 10.

Receiver tracking navigation signal, the clock correction (t of resolving_u-t_s) practical to be receiver time inclined with navigation signal zero Difference, if there is no delay, τ for the 1PPS signals of receiver output_TIC+(t_u-t_s)=TtC, but chain-circuit time delay τ_1PPSInfluence, Lead to τ_TIC+(t_u-t_s) ＞ TtC, therefore 1PPS chain-circuit time delays are：

τ_1PPS=τ_TIC+(t_u-t_s)-TtC (4)；

(5) two parts results added is obtained into receiver delay, τ_REV：

τ_REV=τ_chan+τ_1PPS (5)。

Claims

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 outer For 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 measures The deviation τ of simulator 1PPS signals and receiver output 1PPS signals_TIC；Receiver tracking navigation signal, the clock correction t of resolving_u-t_s For 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。