CN104155664A - Satellite borne receiver timing functional test system and method - Google Patents

Abstract

The invention provides a satellite borne receiver timing functional test system and a method. The system is mainly applicable to the test and evaluation of the timing function of a satellite or spaceship borne navigation receiver in the aerospace field. The system has the following characteristics: (1) compared with the traditional approaches, the measuring accuracy is improved; when a high-stability clock and hardware are adopted to time and the zero value of the testing system is evaluated, the timing measuring accuracy reaches 10 nanosecond scale; (2) the testing coverage is good, the FPGA (Field Programmable Gate Array) is adopted to time and control, the time delay step length of the timing command can be set, in each progression, the full coverage in whole second moment is realized, and the requirement for the randomness testing of timing moment is satisfied; (3) the function integration test can be realized, when parameters are set, the test almost can be automatically executed by the equipment and no operation needs to be conducted by testing staff; when the test is over, the testing result can be generated automatically.

Description

Function test system and method when a kind of spaceborne receiver school

Technical field

Function test system and method for testing while the present invention relates to a kind of spaceborne receiver school, while having realized spaceborne receiver school, integrated, the automatic test of function, can reach higher measuring accuracy, belongs to satellite test technical field.

Background technology

Along with the development of space technology, spaceborne navigation neceiver is played the part of more and more important role, and time service function is one of Core Feature of navigation neceiver, is directly connected to the performance of whole star.

Function while testing the school of spaceborne navigation neceiver, is the important ring in integration test, and need to be to the school of receiver time, function be verified, its precision is carried out to Measurement accuracy.So that function is complete while guaranteeing receiver school, and then ensure that whole star normally works.The functional test modes that adopt artificial+all purpose instrument when traditional spaceborne receiver school more, test macro build process is comparatively loaded down with trivial details, test process is comparatively complicated, must be completed by veteran Test Engineer, and measuring accuracy is relatively low, test coverage deficiency, only can be in the time that comparatively the set time, (whole second) carries out school.

Along with user improves day by day to correcting delay precision and performance requirement, this method of testing exists bottleneck.

Summary of the invention

The problem that technology of the present invention solves is: the deficiency that overcomes existing means of testing, function test system and method for testing when a kind of spaceborne receiver school is provided, adopt embedded technology that test process is integrated in test macro, when while having realized school, the robotization of functional test is with output in real time high-ranking officers, the measuring accuracy of function is brought up to ten nanosecond, has the feature practical, efficiency is high.

Technical solution of the present invention is: function test system when a kind of spaceborne receiver school, comprising: instruction sending module, high steady clock module, difference statistical module, processing module, oscillograph and navigation signal emulator when timing code modular converter, decimal spider module second, null value calibration module, school;

Navigation signal emulator produces pulse per second (PPS) and the timing code corresponding with pulse per second (PPS), and pulse per second (PPS) is sent to decimal spider module second and oscillograph, and timing code is sent to timing code modular converter, second whole second value in the week that described timing code is GPS;

Timing code modular converter extracts the timecode information of navigation signal emulator output, and convert the timing code extracting to the UTC time, then instruction sending module while the UTC time after conversion being exported to school in real time, whole second part of director data during as school;

High steady clock module adopts high stability crystal oscillator module, high stability crystal oscillator during for school instruction sending module and decimal spider module second clock reference is provided;

Instruction sending module when decimal spider module second sent to school by predefined delay time value before the pulse per second (PPS) moment that receives the transmission of navigation signal emulator, decimal spider module second receives after the pulse per second (PPS) of navigation signal emulator transmission, according to predefined delay time value, pulse per second (PPS) is carried out to time delay, and the dominant frequency clock providing by the steady clock module of height carries out the cumulative of internal counter, in the time that the time value of internal counter equates with predefined delay time value, instruction sending module and null value calibration module when pulse per second (PPS) after time delay is exported to school,

, instruction sending module is added the delay time value of the UTC timing code of timing code modular converter output and the output of decimal spider module second when in the school, the content of instruction during as school, instruction sending module when pulse per second (PPS) after the time delay of decimal spider module second output triggers school, when high-ranking officers, command content sends to tested spaceborne navigation neceiver;

When tested spaceborne navigation neceiver receives school when the school of instruction sending module output after instruction, UTC timing code while extracting school in instruction and delay time value, and compare during with inner standard meter, draw time difference, then export to difference statistical module;

Difference statistical module is added up and is stored the time difference receiving, and the time difference after statistics is sent to processing module;

Pulse per second (PPS) after the time delay of null value calibration module reception decimal spider module second output is also exported to oscillograph, ripple device receives the pulse per second (PPS) of navigation signal emulator input and the pulse per second (PPS) of null value calibration module input, and calculate the mistiming between the pulse per second (PPS) of navigation signal emulator input and the pulse per second (PPS) of null value calibration module input, be test macro null value; Test macro null value is exported in real time processing module by oscillograph;

After time difference after the statistics of processing module reception difference statistical module input and the test macro null value of oscillograph input, remove the system zero error in the time difference after statistics according to test macro null value, also output of functional test results while obtaining school.

The correcting delay precision of described system is for being not more than 0.075 μ s.

A method of testing for function test system during based on spaceborne receiver school, step is as follows:

(1) whether judging treatmenting module receives the null value measurement result of test macro, if receive, enters step (2); If do not receive, enter step (9);

(2) the each module in test macro is carried out to initial parameter setting, each module is returned to initial parameter retaking of a year or grade parameter is set;

(3) judge whether configuration successful of initial parameter according to retaking of a year or grade parameter, if configuration successful enters step (4), if there is no configuration successful, enter step (2);

(4) decimal spider module second judges whether to receive the pulse per second (PPS) that navigation signal emulator sends, if receive pulse per second (PPS), enters step (5), if do not receive pulse per second (PPS), continues to judge, until receive pulse per second (PPS);

(5) timing code that test macro sends navigation signal emulator changes into UTC timing code, instruction sending module while then the UTC time after conversion being exported to school in real time, whole second part of director data during as school; Transmitting counter while simultaneously triggering school, enters step (6);

(6) delay duration that while judging school, whether the value of transmitting counter equals to set in advance, if the delay duration that the value of transmitting counter equals to set in advance when school enters step (7); If the value of transmitting counter is less than or equal to the delay duration setting in advance when in the school, the value of transmitting counter adds 1, the delay duration that while rejudging school, whether the value of transmitting counter equals to set in advance when school;

(7) instruction be transferred to tested spaceborne navigation neceiver when the UTC timing code that instruction sending module sends according to timing code modular converter when school and predefined delay time value generate school;

(8) test macro judges whether the time difference signal of receiving that tested spaceborne navigation neceiver sends, if receive, enter step (12), if do not receive, continue to judge, until receive the time difference signal that tested spaceborne navigation neceiver sends; Enter step (12);

(9) oscillograph receives the pulse per second (PPS) of navigation signal emulator transmission and the null value ranging pulse that null value calibration module sends, and calculates difference between the two, is null value measured value, and null value measured value is sent to processing module; Enter step (10);

(10) processing module judgement receives whether the number of times of null value measured value equals default number of times, if equal default number of times, enters step (11); If be less than default number of times, receive that the number of times of null value measured value adds 1, return to step (9);

(11) average of processing module output null value measured value, enters step (12);

(12) the difference statistical module in system and processing module are utilized the average of the null value measured value calculating in time difference signal that the tested spaceborne navigation neceiver receiving in step (8) sends and step (11), average to time difference signal and null value measured value compares, functional measurement result while obtaining school, and measurement result is exported.

The present invention's beneficial effect compared with prior art:

(1) system in the present invention is carried out each functional module integrated, adopts integrated design, and specialized equipment and the common apparatus of numerous and complicated that tradition is needed, integrates in modular mode; Tester only need operate a test macro, has improved testing efficiency, has reduced the complexity that test macro uses;

(2) system in the present invention adopts FPGA to carry out tasks interrupt triggering and time calibrating, is equipped with high steady clock, for measuring accuracy provides instrument guarantee; The design of this system, precision and the spreadability of during for raising school, testing provide effective guarantee;

(3) links of measuring when the method in the present invention is emphasized school carries out quantitatively calibrating, considers the factors such as self null value; Calibration to null value is counted to test process, the precision of having tested while significantly having improved school;

(4) the measurement when method in the present invention makes full use of FPGA and carries out school, while having realized school, function is measured in the traversal of whole second any time (millisecond stepping), has realized accurate timing simultaneously; Spreadability, validity and the measuring accuracy of test are improved;

(5) method in the present invention adopts the mode of automatic test, and tester writes test case, and test instruction is carried out to serializing layout, utilizes the advantage of integrated system, and manual operation is simplified, and substantially realizes one-touch test; Effectively improve testing efficiency, reduced the professional requirement to tester, while having improved school, tested consistance.

Brief description of the drawings

Function test system composition diagram when Fig. 1 school;

Test flow chart when Fig. 2 school;

Fig. 3 correcting delay precision is measured sequential chart.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is at length set forth.

Be illustrated in figure 1 system chart of the present invention, as shown in Figure 1, function test system when the spaceborne receiver of one school that the present invention proposes, comprising: instruction sending module when timing code modular converter, decimal spider module second, null value calibration module, school, high steady clock module, difference statistical module, processing module, oscillograph and navigation signal emulator;

Navigation signal emulator produces pulse per second (PPS) and the timing code corresponding with pulse per second (PPS), and pulse per second (PPS) is sent to decimal spider module second and oscillograph, and timing code is sent to timing code modular converter, second whole second value in the week that described timing code is GPS;

Timing code modular converter extracts the timecode information of navigation signal emulator output, and convert the timing code extracting to the UTC time, then instruction sending module while the UTC time after conversion being exported to school in real time, whole second part of director data during as school; UTC (the Coordinated Universal Time) time is the Coordinated Universal Time(UTC), it is a kind of universal time, universal time and International Atomic Time a kind of half-way house between the two, time format resolve as: 23: 59: 58 on the 31st Dec in 2005.

High steady clock module adopts high stability crystal oscillator module, high stability crystal oscillator during for school instruction sending module and little tree spider module second high precision clock benchmark is provided; The precision of selected high stability crystal oscillator is :≤± 0.2ppm; Degree of stability is :≤± 1ppm/year.

Instruction sending module when decimal spider module second sent to school by predefined delay time value before the pulse per second (PPS) moment that receives the transmission of navigation signal emulator, decimal spider module second receives after the pulse per second (PPS) of navigation signal emulator transmission, according to predefined delay time value, pulse per second (PPS) is carried out to time delay, and the dominant frequency clock providing by the steady clock module of height carries out the cumulative of internal counter, in the time that the time value of internal counter equates with predefined delay time value, instruction sending module and null value calibration module when pulse per second (PPS) after time delay is exported to school,

, instruction sending module is added the delay time value of the UTC timing code of timing code modular converter output and the output of decimal spider module second when in the school, the content of instruction during as school, instruction sending module when pulse per second (PPS) after the time delay of decimal spider module second output triggers school, when high-ranking officers, command content sends to tested spaceborne navigation neceiver;

When tested spaceborne navigation neceiver receives school when the school of instruction sending module output after instruction, UTC timing code while extracting school in instruction and delay time value, and compare during with inner standard meter, draw time difference, then export to difference statistical module;

Difference statistical module is added up and is stored the time difference receiving, and the time difference after statistics is sent to processing module; Described statistical method comprises averages and least square method, and statistical method can be configured at software interface, and tester can select wherein a kind of statistical method.Described precision is single measurement precision herein.

Pulse per second (PPS) after the time delay of null value calibration module reception decimal spider module second output is also exported to oscillograph, ripple device receives the pulse per second (PPS) of navigation signal emulator input and the pulse per second (PPS) of null value calibration module input, and calculate the mistiming between the pulse per second (PPS) of navigation signal emulator input and the pulse per second (PPS) of null value calibration module input, be test macro null value; Test macro null value is exported in real time processing module by oscillograph;

After time difference after the statistics of processing module reception difference statistical module input and the test macro null value of oscillograph input, remove the system zero error in the time difference after statistics according to test macro null value, also output of functional test results while obtaining school.

Be illustrated in figure 2 the method flow diagram in the present invention, as shown in Figure 2, the present invention propose a kind of spaceborne receiver school based on test macro time function test method, step is as follows:

(1) judge whether test macro has completed null value and measured, and measures if completed null value, enters step (2); Measure if do not complete null value, enter step (9);

(2) the each module in test macro is carried out to initial parameter setting, each module is returned to initial parameter retaking of a year or grade parameter is set;

(3) judge whether configuration successful of initial parameter according to retaking of a year or grade parameter, if configuration successful enters step (4), if there is no configuration successful, enter step (2);

(4) decimal spider module second judges whether to receive the pulse per second (PPS) that navigation signal emulator sends, if receive pulse per second (PPS), enters step (5), if do not receive pulse per second (PPS), continues to judge, until receive pulse per second (PPS);

(5) timing code that test macro sends navigation signal emulator changes into UTC timing code, instruction sending module while then the UTC time after conversion being exported to school in real time, whole second part of director data during as school; Transmitting counter while simultaneously triggering school, enters step (6);

(6) delay duration that while judging school, whether the value of transmitting counter equals to set in advance, if the delay duration that the value of transmitting counter equals to set in advance when school enters step (7); If the value of transmitting counter is less than or equal to the delay duration setting in advance when in the school, the value of transmitting counter adds 1, the delay duration that while rejudging school, whether the value of transmitting counter equals to set in advance when school;

(7) instruction be transferred to tested spaceborne navigation neceiver when the UTC timing code that instruction sending module sends according to timing code modular converter when school and predefined delay time value generate school;

(8) test macro judges whether the time difference signal of receiving that tested spaceborne navigation neceiver sends, if receive, enter step (12), if do not receive, continue to judge, until receive the time difference signal that tested spaceborne navigation neceiver sends; Enter step (12);

(9) oscillograph receives the pulse per second (PPS) of navigation signal emulator transmission and the null value ranging pulse that null value calibration module sends, and calculates difference between the two, is null value measured value, and null value measured value is sent to processing module; Enter step (10);

(10) processing module judgement receives whether the number of times of null value measured value equals default number of times, if equal default number of times, enters step (11); If be less than default number of times, receive that the number of times of null value measured value adds 1, return to step (9);

(11) average of processing module output null value measured value, enters step (12);

(12) the difference statistical module in system and processing module are utilized the average of the null value measured value calculating in time difference signal that the tested spaceborne navigation neceiver receiving in step (8) sends and step (11), average to time difference signal and null value measured value compares, functional measurement result while obtaining school, and measurement result is exported.

Principle of work of the present invention:

, the enforcement of function integrated test system mainly when in the school: system chassis is that standard C pci bus interface cabinet, the controller of buying is the standard main control module of buying; Timing code modular converter and decimal spider module second during mainly by school the FPGA in functional module realize; Null value calibration module during mainly by school the FPGA in functional module realize; High steady clock module is the high steady clock chip of technical grade; Difference statistical module and analysis software are that host computer develops software from grinding.

, the method for testing of function is mainly when in the school: emulator sends pulse per second (PPS), through test macro processing, and instruction while sending school, then return to difference by receiver, difference is proofreaied and correct to assessment correcting delay precision.Sequential chart as shown in Figure 3.

T _td1: pulse per second (PPS) transmission delay, emulator is to the cable transmission time delay of test macro;

T _rz: test macro receives null value, and test macro receives pulse per second (PPS) to the time delay of decimal spider module second;

T _pd: the processing time delay of test macro decimal spider module second;

T _tz: test macro sends null value, instruction time delay when bus sends school;

T _td2: command time delay, instruction time delay when bus transfer school;

T _b: return to difference: school time difference value, for comparing with receiver rreturn value;

Receiver receives the time delay of bus command to inter-process module, will measure or assess (null value is measured and theoretical calculating combines) result offer Test Engineer by spaceborne navigation neceiver designer.

From sequential chart:

t _b＝t _td1+t _rz+t _tz+t _td2

Functional test while carrying out school according to the method, supposes that the difference that receiver returns is t _rb, measurement result t while in fact testing the school that will obtain _sfor

t _s＝|t _rb-t _b|

T _pdnot in computing formula, because t _pdbe the numerical value that test macro is known,, instruction meeting is by t when in test macro sends the school _pdnumerical value count, the difference that therefore receiver returns does not comprise t _pd.But due to t _pdfor actual program time delay, with theoretical programming time delay t ' _pddifference can impact correcting delay precision measurement.

Further arranging formula obtains:

t _s＝t _rb+t′ _pd-t _pd-t _td1-t _rz-t _td2

If y=f is (x ₁, x ₂..., x _m) m independent variable x of expression ₁, x ₂..., x _mfunction, if independent variable x ₁, x ₂..., x _mmaximum error be respectively Δ x ₁, Δ x ₂..., Δ x _m, the computing formula of the maximum absolute error Δ y of function y is:

$\mathrm{\Δy}=\left|\frac{\∂f}{{\∂x}_1}\right|{\mathrm{\Δx}}_1+\left|\frac{\∂f}{{\∂x}_2}\right|{\mathrm{\Δx}}_2+...+\left|\frac{\∂f}{{\∂x}_m}\right|{\mathrm{\Δx}}_m$

During due to school, the relation of the time difference and each variable is cumulative, and therefore above formula can be reduced to formula:

Δ(x ₁±x ₂±…±x _m)≤Δx ₁+Δx ₂+…+Δx _m

T _td1for cable transmission precision, suppose that pulse per second (PPS) transmission cable length is 2 meters (being generally no more than 5 meters), t _td1result of calculation is:

t _td1＝2/c

In formula, c is the light velocity, t _td1estimation error is less than 5ns.

T _rzwith t _tzinterrupt relevantly with treatment mechanism to the inner embedded program of printed board cabling, test macro, theoretical calculating cannot accurate evaluation, need survey it.Measurement method is as follows: test macro adopts null detection program, and pulse per second (PPS) is inputed to test macro, instruction when test macro receives and sends school immediately after pulse per second (PPS), instruction the first bit leading edge time while surveying pulse per second (PPS) and school by oscillograph.According to oscillographic performance, estimation error is less than 10ns.

T _td2instruction time delay when bus transfer school,, instruction is made up of some bytes when in bus the school, and, the transmission of instruction needs the time when in the school, therefore needs t _td2assess., bus mainly contains 1553B bus and CAN bus when in the conventional school of spaceborne navigation neceiver, and the byte length of instruction during according to school, can send required time to it and calculate comparatively accurately.Estimation error is less than 50ns.

While carrying out fixed response time due to employing FPGA, and the clock source adopting is high steady clock, therefore actual program time delay t _pdwith theoretical programming time delay t ' _pddifference estimation error be less than 10ns.

Therefore t _serror, the precision result of measuring when school is:

t _s≤0.075μs

Embodiment

(1) carry out initial parameter setting; For example, the output pulse per second (PPS) of navigation signal source emulator and timing code are set, bus interface parameter when school is set, the RT subaddressing of 1553B bus is that the speed of 31, CAN bus is 500Kbps etc., and it is 10ms that pulse per second (PPS) step-length is set, and it is average that difference statistical method is set;

(2) carry out the judgement of retaking of a year or grade parameter, click " retaking of a year or grade " button of software, parameters initial parameter is presented in corresponding text box, judges that whether the numerical value of retaking of a year or grade conforms to configuration, conforms to and can start null value measurement;

(3) measure when school, time delay is carried out in the pulse per second (PPS) that decimal spider module second of test macro sends signal simulation device, time delay is for arranging step-length 10ms, during through school, instruction interface circuit sends to oscillograph, oscillograph is compared the pulse per second (PPS) of this signal and the transmission of signal simulation device, show that difference deducts step value and is null value, and for example difference is 10.001ms, null value is 1us, and null value can repeatedly be measured and average.

(4) whether observed and had null value measured value to return by software interface, return if any null value, for example, rreturn value, can start test while carrying out school, otherwise wait for and return to null value measured value always if being 1us;

(5) test process starts when school, and test macro receives the pulse per second (PPS) of signal simulation device output, the low pulse that pulsewidth is 10ms, and the timing code of output be second in week, for example, be 1000;

(6) timing code that test macro sends navigation signal emulator changes into UTC timing code, it is for example 12: 30: 30 on the 1st May in 2013, instruction sending module when this numerical value is sent to the school of test macro inside as whole second part, instruction sending module while simultaneously the step-length 10ms of setting being sent to school equally; Trigger decimal counter second simultaneously and open, judge whether timing equals the step-length arranging, and while equating to trigger school, instruction sending module starts;

(7) instruction is sent to tested navigation neceiver when instruction sending module high-ranking officers when test macro school, then receives the difference that navigation neceiver returns, for example, be 11us; The result of single measurement is that difference deducts null value, is 11us-1us=10us, and according to precision analysis before, the measuring accuracy of this measurement result 10us can reach ten nanosecond.

(8) repeatedly measure situation about being averaged, the judgement of test macro processing module receives whether the number of times of null value measured value equals default number of times, and for example, number of times all equals 100 times, carries out result statistics, and the result drawing is effective result.

Adopt the system and method in the present invention, the accurate test of function and precision thereof can complete spaceborne navigation neceiver school time, when, the robotization of functional test is with output in real time high-ranking officers when in the school, the measuring accuracy of function is brought up to ten nanosecond, during to receiver school, the checking of function and the measurement of its precision thereof and raising all provide the data basis of science, have the feature practical, efficiency is high.

The present invention not detailed description is known to the skilled person technology.

Claims (3)

1. function test system when spaceborne receiver school, is characterized in that comprising: instruction sending module, high steady clock module, difference statistical module, processing module, oscillograph and navigation signal emulator when timing code modular converter, decimal spider module second, null value calibration module, school;

Navigation signal emulator produces pulse per second (PPS) and the timing code corresponding with pulse per second (PPS), and pulse per second (PPS) is sent to decimal spider module second and oscillograph, and timing code is sent to timing code modular converter, second whole second value in the week that described timing code is GPS;

Timing code modular converter extracts the timecode information of navigation signal emulator output, and convert the timing code extracting to the UTC time, then instruction sending module while the UTC time after conversion being exported to school in real time, whole second part of director data during as school;

High steady clock module adopts high stability crystal oscillator module, high stability crystal oscillator during for school instruction sending module and decimal spider module second clock reference is provided;

Instruction sending module when decimal spider module second sent to school by predefined delay time value before the pulse per second (PPS) moment that receives the transmission of navigation signal emulator, decimal spider module second receives after the pulse per second (PPS) of navigation signal emulator transmission, according to predefined delay time value, pulse per second (PPS) is carried out to time delay, and the dominant frequency clock providing by the steady clock module of height carries out the cumulative of internal counter, in the time that the time value of internal counter equates with predefined delay time value, instruction sending module and null value calibration module when pulse per second (PPS) after time delay is exported to school,

, instruction sending module is added the delay time value of the UTC timing code of timing code modular converter output and the output of decimal spider module second when in the school, the content of instruction during as school, instruction sending module when pulse per second (PPS) after the time delay of decimal spider module second output triggers school, when high-ranking officers, command content sends to tested spaceborne navigation neceiver;

When tested spaceborne navigation neceiver receives school when the school of instruction sending module output after instruction, UTC timing code while extracting school in instruction and delay time value, and compare during with inner standard meter, draw time difference, then export to difference statistical module;

Difference statistical module is added up and is stored the time difference receiving, and the time difference after statistics is sent to processing module;

Pulse per second (PPS) after the time delay of null value calibration module reception decimal spider module second output is also exported to oscillograph, ripple device receives the pulse per second (PPS) of navigation signal emulator input and the pulse per second (PPS) of null value calibration module input, and calculate the mistiming between the pulse per second (PPS) of navigation signal emulator input and the pulse per second (PPS) of null value calibration module input, be test macro null value; Test macro null value is exported in real time processing module by oscillograph;

After time difference after the statistics of processing module reception difference statistical module input and the test macro null value of oscillograph input, remove the system zero error in the time difference after statistics according to test macro null value, also output of functional test results while obtaining school.

2. function test system when the spaceborne receiver of one according to claim 1 school, is characterized in that: the correcting delay precision of described system is for being not more than 0.075 μ s.

3. function test method when the spaceborne receiver school of the test macro based in claim 1, is characterized in that step is as follows:

(1) whether judging treatmenting module receives the null value measurement result of test macro, if receive, enters step (2); If do not receive, enter step (9);

(2) the each module in test macro is carried out to initial parameter setting, each module is returned to initial parameter retaking of a year or grade parameter is set;

(3) judge whether configuration successful of initial parameter according to retaking of a year or grade parameter, if configuration successful enters step (4), if there is no configuration successful, enter step (2);

(4) decimal spider module second judges whether to receive the pulse per second (PPS) that navigation signal emulator sends, if receive pulse per second (PPS), enters step (5), if do not receive pulse per second (PPS), continues to judge, until receive pulse per second (PPS);

(5) timing code that test macro sends navigation signal emulator changes into UTC timing code, instruction sending module while then the UTC time after conversion being exported to school in real time, whole second part of director data during as school; Transmitting counter while simultaneously triggering school, enters step (6);

(6) delay duration that while judging school, whether the value of transmitting counter equals to set in advance, if the delay duration that the value of transmitting counter equals to set in advance when school enters step (7); If the value of transmitting counter is less than or equal to the delay duration setting in advance when in the school, the value of transmitting counter adds 1, the delay duration that while rejudging school, whether the value of transmitting counter equals to set in advance when school;

(7) instruction be transferred to tested spaceborne navigation neceiver when the UTC timing code that instruction sending module sends according to timing code modular converter when school and predefined delay time value generate school;

(8) test macro judges whether the time difference signal of receiving that tested spaceborne navigation neceiver sends, if receive, enter step (12), if do not receive, continue to judge, until receive the time difference signal that tested spaceborne navigation neceiver sends; Enter step (12);

(9) oscillograph receives the pulse per second (PPS) of navigation signal emulator transmission and the null value ranging pulse that null value calibration module sends, and calculates difference between the two, is null value measured value, and null value measured value is sent to processing module; Enter step (10);

(10) processing module judgement receives whether the number of times of null value measured value equals default number of times, if equal default number of times, enters step (11); If be less than default number of times, receive that the number of times of null value measured value adds 1, return to step (9);

(11) average of processing module output null value measured value, enters step (12);

(12) the difference statistical module in system and processing module are utilized the average of the null value measured value calculating in time difference signal that the tested spaceborne navigation neceiver receiving in step (8) sends and step (11), average to time difference signal and null value measured value compares, functional measurement result while obtaining school, and measurement result is exported.