CN106054217A - Code observation method of GNSS receiver - Google Patents

Abstract

The invention discloses a code observation method of a GNSS receiver. The method comprises the steps of: 1, calculating a code observation equation which is shown in the specification; 2, setting a clock error [delta]tr of the receiver, a clock error [delta]ts of a satellite since a satellite clock and the receiving clock are not synchronous, and obtaining the following formulas which are shown in the specification; 3, substituting the formulas in the step 2 into the code observation equation, and obtaining the following formula which is shown in the specification; 4, calculating [tau]<s><r> and [delta][tau]<s><r>, and obtaining the following formulas which are shown in the specification; and 5, substituting the formulas in the step 4 into the formula in the step 3, and obtaining the following formula which is shown in the specification. By adopting the code observation method of the GNSS receiver, the code observation distance precision can be greatly improved.

Description

A kind of method of GNSS receiver code observation

Technical field

The method that the present invention relates to the observation of a kind of GNSS receiver code, belongs to technical field of navigation and positioning.

Background technology

GNSS is the abbreviation of Global Navigation Satellite System.Chinese translation is global navigational satellite System.At present, GNSS contains the GPS of the U.S., Muscovite GLONASS, the Galileo system of European Union, the Compass of China (Big Dipper), after all building up, its available number of satellite reaches more than 100.

The basic observation of GNSS receiver is the signal propagation time from satellite to receiver, produces inside receiver Replica code, and postpone reasonable time and align with the satellite-signal received, propagate by measuring this retardation signal calculated Time.Owing to code measurement observation is by many impacts such as satellite clock, receiver clock and atmosphere errors, so being found range From with actual distance unequal, how improving surveyed range accuracy is our urgent problem.

Summary of the invention

Purpose: in order to overcome the deficiencies in the prior art, the present invention provides the side that a kind of GNSS receiver code is observed Method.

Technical scheme: for solving above-mentioned technical problem, the technical solution used in the present invention is:

The method of a kind of GNSS receiver code observation, comprises the following steps that

Step one: calculating code observational equation:

In formulaFor the code observed quantity in satellite s to receiver r；T is Observation time；C is the light velocity in vacuum；t_rThe time received by receiver r for signal；t^sFor signal when satellite s is launched Between；For signal from satellite s to the propagation time of receiver r；For code measurement error；

Step 2: owing to satellite clock is asynchronous with reception clock, if receiver clock-offsets δ t_r, satellite clock correction δ t^s, obtain following formula:

$\begin{array}{c}{t}_r\left(t\right)=t+{\mathrm{\&delta;t}}_r\left(t\right)\\ t^s(t-{\mathrm{\&tau;}}_r^s)=t-{\mathrm{\&tau;}}_r^s+{\mathrm{\&delta;t}}^s(t-{\mathrm{\&tau;}}_r^s)\end{array};$

Step 3: the formula in step 2 is substituted into code observational equation, obtains following formula:

$P_r^s\left(t\right)={\mathrm{c\&tau;}}_r^s+c\&lsqb;{\mathrm{\&delta;t}}_r\left(t\right)-{\mathrm{\&delta;t}}^s(t-{\mathrm{\&tau;}}_r^s)\&rsqb;+{\mathrm{\&epsiv;}}_r^s\left(t\right);$

Step 4: calculateObtain following formula:

In formula, δ τ is the signal propagation time from satellite antenna to receiver antenna； d_rHardware code for receiver end postpones；d^sHardware code for satellite end postpones；ρ is the geometric distance between satellite and receiver；For ionosphere delay；For tropospheric delay；Postpone for multipath；

Step 5: the formula in step 4 substitutes into the formula in step 3, obtains following formula:

$P_r^s\left(t\right)={\mathrm{\&rho;}}_r^s(t,t-{\mathrm{\&tau;}}_r^s)+I_r^s\left(t\right)+T_r^s\left(t\right)+{\mathrm{\&delta;m}}_r^s\left(t\right)+c\&lsqb;{\mathrm{\&delta;t}}_r\left(t\right)-{\mathrm{\&delta;t}}^s(t-{\mathrm{\&tau;}}_r^s)\&rsqb;+c\&lsqb;d_r\left(t\right)+d^s(t-{\mathrm{\&tau;}}_r^s)\&rsqb;{\mathrm{\&epsiv;}}_r^s\left(t\right).$

Beneficial effect: the method for a kind of GNSS receiver code observation that the present invention provides, by the investigation to different variablees, The precision of yard observed range can be greatly improved.

Detailed description of the invention

The method of a kind of GNSS receiver code observation, comprises the following steps that

Step one: calculating code observational equation:

In formulaFor the code observed quantity in satellite s to receiver r；T is Observation time；C is the light velocity in vacuum；t_rThe time received by receiver r for signal；t^sFor signal when satellite s is launched Between；For signal from satellite s to the propagation time of receiver r；For code measurement error；

Step 2: owing to satellite clock is asynchronous with reception clock, if receiver clock-offsets δ t_r, satellite clock correction δ t^s, under obtaining Formula:

$\begin{array}{c}{t}_r\left(t\right)=t+{\mathrm{\&delta;t}}_r\left(t\right)\\ t^s(t-{\mathrm{\&tau;}}_r^s)=t-{\mathrm{\&tau;}}_r^s+{\mathrm{\&delta;t}}^s(t-{\mathrm{\&tau;}}_r^s)\end{array};$

Step 3: the formula in step 2 is substituted into code observational equation, obtains following formula:

$P_r^s\left(t\right)={\mathrm{c\&tau;}}_r^s+c\&lsqb;{\mathrm{\&delta;t}}_r\left(t\right)-{\mathrm{\&delta;t}}^s(t-{\mathrm{\&tau;}}_r^s)\&rsqb;+{\mathrm{\&epsiv;}}_r^s\left(t\right);$

Step 4: calculateObtain following formula:

In formula, δ τ is the signal propagation time from satellite antenna to receiver antenna； d_rHardware code for receiver end postpones；d^sHardware code for satellite end postpones；ρ is the geometric distance between satellite and receiver；For ionosphere delay；For tropospheric delay；Postpone for multipath；

Step 5: the formula in step 4 substitutes into the formula in step 3, obtains following formula:

$P_r^s\left(t\right)={\mathrm{\&rho;}}_r^s(t,t-{\mathrm{\&tau;}}_r^s)+I_r^s\left(t\right)+T_r^s\left(t\right)+{\mathrm{\&delta;m}}_r^s\left(t\right)+c\&lsqb;{\mathrm{\&delta;t}}_r\left(t\right)-{\mathrm{\&delta;t}}^s(t-{\mathrm{\&tau;}}_r^s)\&rsqb;+c\&lsqb;d_r\left(t\right)+d^s(t-{\mathrm{\&tau;}}_r^s)\&rsqb;{\mathrm{\&epsiv;}}_r^s\left(t\right).$

The above is only the preferred embodiment of the present invention, it should be pointed out that: for the ordinary skill people of the art For Yuan, under the premise without departing from the principles of the invention, it is also possible to make some improvements and modifications, these improvements and modifications also should It is considered as protection scope of the present invention.

Claims (1)

1. the method for a GNSS receiver code observation, it is characterised in that: comprise the following steps that

Step one: calculating code observational equation:

In formulaFor the code observed quantity in satellite s to receiver r；T is observation Time；C is the light velocity in vacuum；t_rThe time received by receiver r for signal；t^sThe time launched from satellite s for signal； For signal from satellite s to the propagation time of receiver r；For code measurement error；

Step 2: owing to satellite clock is asynchronous with reception clock, if receiver clock-offsets δ t_r, satellite clock correction δ t^s, obtain following formula:

$\begin{array}{c}{t}_r\left(t\right)=t+{\mathrm{\&delta;t}}_r\left(t\right)\\ t^s(t-{\mathrm{\&tau;}}_r^s)=t-{\mathrm{\&tau;}}_r^s+{\mathrm{\&delta;t}}^s(t-{\mathrm{\&tau;}}_r^s)\end{array};$

Step 3: the formula in step 2 is substituted into code observational equation, obtains following formula:

$P_r^s\left(t\right)={\mathrm{c\&tau;}}_r^s+c\&lsqb;{\mathrm{\&delta;t}}_r\left(t\right)-{\mathrm{\&delta;t}}^s(t-{\mathrm{\&tau;}}_r^s)\&rsqb;+{\mathrm{\&epsiv;}}_r^s\left(t\right);$

Step 4: calculateObtain following formula:

In formula, δ τ is the signal propagation time from satellite antenna to receiver antenna；d_rFor The hardware code of receiver end postpones；d^sHardware code for satellite end postpones；ρ is the geometric distance between satellite and receiver； For ionosphere delay；For tropospheric delay；Postpone for multipath；

Step 5: the formula in step 4 substitutes into the formula in step 3, obtains following formula:

$P_r^s\left(t\right)={\mathrm{\&rho;}}_r^s(t,t-{\mathrm{\&tau;}}_r^s)+I_r^s\left(t\right)+T_r^s\left(t\right)+{\mathrm{\&delta;m}}_r^s\left(t\right)+c\&lsqb;{\mathrm{\&delta;t}}_r\left(t\right)-{\mathrm{\&delta;t}}^s(t-{\mathrm{\&tau;}}_r^s)\&rsqb;+c\&lsqb;d_r\left(t\right)+d^s(t-{\mathrm{\&tau;}}_r^s)\&rsqb;{\mathrm{\&epsiv;}}_r^s\left(t\right).$