GNSS antenna performance testing system, method, device and readable storage medium

Abstract

The present invention provides a GNSS antenna performance testing system, method, apparatus, and readable storage medium, all of which pertain to GNSS technology. The system comprises: a standard GNSS antenna and a GNSS antenna under test receiving first and second GNSS satellite signals, respectively, from GNSS satellites; first and second GNSS radio frequency circuits acquiring first and second IQ digital signals, respectively, based on the first and second GNSS satellite signals; a GNSS baseband processing and analysis circuit acquiring first and second C / N0 sequences, respectively, based on the first and second IQ digital signals; and determining the gain and / or pattern performance of the GNSS antenna under test based on the first and second C / N0 sequences. The system is low-cost and easy to implement for GNSS antenna performance testing under a real starry sky. It can accurately evaluate the performance of the GNSS antenna under test, improving the effectiveness of evaluating the performance of the GNSS antenna under test.

Description

Technical Field

[0001] The present application relates to the field of GNSS technology, and in particular to a GNSS antenna performance testing system, method, device, and readable storage medium. Background Art

[0002] Currently, the most widely used Global Navigation Satellite Systems (GNSS) include the US Global Positioning System (GPS), the Russian Global Navigation Satellite System (GLONASS), the European Union's Galileo satellite navigation system (GALILEO), and China's BeiDou satellite navigation system.

[0003] GNSS antennas are a crucial component of GNSS receivers, and their performance directly impacts the receiver's positioning accuracy. GNSS antennas can be categorized as active or wireless. Existing testing requires a standard microwave anechoic chamber to test key GNSS antenna specifications. Testing GNSS antenna performance also requires at least the following equipment: a turntable, turntable controller, satellite signal simulator, transmitting antenna, spectrum analyzer, and vector signal generator, resulting in significant costs associated with establishing a GNSS antenna test environment. Summary of the Invention

[0004] In order to solve the above technical problems, the embodiments of the present application provide a GNSS antenna performance testing system, method, device and readable storage medium.

[0005] In a first aspect, an embodiment of the present application provides a GNSS antenna performance testing system, wherein the GNSS antenna performance testing method includes:

[0006] The invention comprises: an antenna device and a GNSS receiving and processing device, wherein the antenna device comprises a standard GNSS antenna and a GNSS antenna under test, and the GNSS receiving and processing device comprises a first GNSS radio frequency circuit, a second GNSS radio frequency circuit, and a GNSS baseband processing and analysis circuit;

[0007] The standard GNSS antenna is used to receive a first GNSS satellite signal from a GNSS satellite;

[0008] The GNSS antenna under test is used to receive a second GNSS satellite signal from the GNSS satellite;

[0009] The first GNSS radio frequency circuit is configured to obtain a first IQ digital signal according to the first GNSS satellite signal;

[0010] The second GNSS radio frequency circuit is configured to obtain a second IQ digital signal according to the second GNSS satellite signal;

[0011] The GNSS baseband processing and analysis circuit is configured to obtain a first C / N0 sequence based on the first IQ digital signal, and obtain a second C / N0 sequence based on the second IQ digital signal; and determine the gain and / or pattern performance of the GNSS antenna under test based on the first C / N0 sequence and the second C / N0 sequence.

[0012] In a second aspect, an embodiment of the present application provides a GNSS antenna performance testing method, which is applied to the GNSS antenna performance testing system provided in the first aspect. The GNSS antenna performance testing method includes:

[0013] receiving a first GNSS satellite signal from a GNSS satellite;

[0014] receiving a second GNSS satellite signal from the GNSS satellite;

[0015] Acquire a first IQ digital signal according to the first GNSS satellite signal;

[0016] Acquire a second IQ digital signal according to the second GNSS satellite signal;

[0017] Acquire a first C / N0 sequence according to the first IQ digital signal, and acquire a second C / N0 sequence according to the second IQ digital signal;

[0018] The gain and / or pattern performance of the GNSS antenna under test is determined according to the first C / N0 sequence and the second C / N0 sequence.

[0019] In a third aspect, an embodiment of the present application provides a GNSS antenna performance testing device, comprising: a first receiving module, configured to receive a first GNSS satellite signal from a GNSS satellite;

[0020] A second receiving module, configured to receive a second GNSS satellite signal from the GNSS satellite;

[0021] A first acquisition module, configured to acquire a first IQ digital signal according to the first GNSS satellite signal;

[0022] A second acquisition module, configured to acquire a second IQ digital signal according to the second GNSS satellite signal;

[0023] a third acquisition module, configured to acquire a first C / N0 sequence according to the first IQ digital signal, and acquire a second C / N0 sequence according to the second IQ digital signal;

[0024] A determination module is configured to determine the gain and / or pattern performance of the GNSS antenna under test according to the first C / N0 sequence and the second C / N0 sequence.

[0025] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium storing a computer program, which, when running on a processor, executes the GNSS antenna performance testing method provided in the second aspect.

[0026] The GNSS antenna performance testing system, method, apparatus, and readable storage medium provided by the present application include a standard GNSS antenna for receiving a first GNSS satellite signal from a GNSS satellite; a GNSS antenna under test for receiving a second GNSS satellite signal from a GNSS satellite; a first GNSS radio frequency circuit for acquiring a first IQ digital signal based on the first GNSS satellite signal; a second GNSS radio frequency circuit for acquiring a second IQ digital signal based on the second GNSS satellite signal; a GNSS baseband processing and analysis circuit for acquiring a first C / N0 sequence based on the first IQ digital signal and a second C / N0 sequence based on the second IQ digital signal; and determining the gain and / or pattern performance of the GNSS antenna under test based on the first C / N0 sequence and the second C / N0 sequence. Thus, the system is low-cost and easy to implement GNSS antenna performance testing under a real starry sky. By placing the GNSS antenna under test in a real starry sky environment and application scenario for testing, the performance of the GNSS antenna under test can be accurately evaluated, thereby improving the evaluation effect of the GNSS antenna under test performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of this application and should not be regarded as limiting the scope of protection of this application. In each of the drawings, similar components are numbered similarly.

[0028] Figure 1 A schematic structural diagram of a GNSS antenna performance test system provided in an embodiment of the present application is shown;

[0029] Figure 2 A schematic diagram of a C / N0 curve of a CO3 star provided in an embodiment of the present application is shown;

[0030] Figure 3 Another C / N0 curve of a CO3 star provided in an embodiment of the present application is shown;

[0031] Figure 4 It shows a partial starry sky of the BeiDou GEO satellite provided by the embodiment of the present application;

[0032] Figure 5 Another partial starry sky view of the BeiDou GEO satellite provided by an embodiment of the present application is shown;

[0033] Figure 6 It shows a partial starry sky of the BeiDou MEO satellite provided by the embodiment of the present application;

[0034] Figure 7 Another partial starry sky view of the BeiDou MEO satellite provided by an embodiment of the present application is shown;

[0035] Figure 8 It shows a partial starry sky of GPS satellites provided by an embodiment of the present application;

[0036] Figure 9 Another partial starry sky view of a GPS satellite provided by an embodiment of the present application is shown;

[0037] Figure 10 It shows a panoramic starry sky view of the GNSS antenna provided by an embodiment of the present application;

[0038] Figure 11 Another flow chart of the GNSS antenna performance testing system provided in an embodiment of the present application is shown;

[0039] Figure 12 A schematic diagram of a process for testing the performance of a GNSS antenna according to an embodiment of the present application is shown;

[0040] Figure 13 A structural schematic diagram of a GNSS antenna performance testing device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0042] The components of the embodiments of the present application generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but rather merely represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0043] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present application, are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0044] Furthermore, the terms “first,” “second,” “third,” etc., are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0045] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meaning as in the context of the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning unless clearly defined in the various embodiments of the present application.

[0046] Example 1

[0047] The present application provides a GNSS antenna performance test system for testing GNSS antenna performance under a real starry sky. This system is low-cost and easy to implement under a real starry sky. By placing the GNSS antenna under test in a real starry sky environment and application scenario, it can accurately evaluate the performance of the GNSS antenna under test, thereby improving the evaluation effect of the GNSS antenna under test. The system is described below with reference to the accompanying figures.

[0048] See also Figure 1 The GNSS antenna performance test system includes: an antenna device 100 and a GNSS receiving and processing device 200, wherein the antenna device includes a standard GNSS antenna 101 and a GNSS antenna under test 102, and the GNSS receiving and processing device 200 includes a first GNSS radio frequency circuit 201, a second GNSS radio frequency circuit 202, and a GNSS baseband processing and analysis circuit 203.

[0049] Among them, the standard GNSS antenna 101 and the GNSS antenna under test 102 can synchronously receive satellite signals sent by various GNSS satellites. The standard GNSS antenna 101 is a GNSS antenna with pre-known technical indicators. Since the antenna performance of the standard GNSS antenna 101 is known, it serves as a reference antenna for comparison with the GNSS antenna under test 102. The GNSS antenna under test 102 is a GNSS antenna that needs to be tested to obtain antenna performance under real sky conditions. The first GNSS RF circuit 201 and the second GNSS RF circuit 202 are respectively connected to the GNSS baseband processing and analysis circuit 203. The first GNSS RF circuit 201 is also connected to the standard GNSS antenna 101, and the second GNSS RF circuit 202 is also connected to the second GNSS RF circuit 202. It should be noted that the various GNSS satellites can include various satellites in GPS, various satellites in GLONASS, and various satellites in China's BeiDou Satellite Navigation System.

[0050] In this embodiment, based on the actual application scenarios of GNSS antennas, it can be seen that the gain and radiation pattern of the GNSS antenna directly affect the C / N0 value resolved by the GNSS receiver to the satellite. Under the real starry sky, factors affecting GNSS antenna performance include the following: ionospheric refraction, tropospheric refraction, multipath effect, antenna phase center deviation, antenna polarization mode, weather factors, and other interference signals. The standard microwave anechoic chamber used in the existing technology cannot simulate these factors affecting GNSS antenna performance. Therefore, the GNSS antenna performance results measured in the standard microwave anechoic chamber are relatively ideal, and there is a significant difference between the antenna performance of GNSS antennas in actual application scenarios. In this embodiment, the GNSS antenna performance test system is placed under the real starry sky to perform performance testing on the GNSS antenna under test. This can comprehensively reflect the impact of various factors in the real starry sky on the performance of the GNSS antenna under test, and obtain more accurate performance test results for the GNSS antenna under test.

[0051] It is further explained that, under the real starry sky, the test location of the GNSS antenna performance test system can be selected to be closer to the actual application scenario of the GNSS antenna. Exemplarily, the actual application scenarios can be divided into the following three categories: the first category of scenarios is open space scenarios, such as the roof of an office building or a park square. The second category of scenarios is half-starry sky scenarios, such as the north-south scene or the east-west scene of a high-rise building. The third category of scenarios is an urban canyon scene, such as a street with high-rise buildings. Among them, the first category of scenarios is close to the standard microwave darkroom in the prior art. The present invention can select any one or all of the first, second and third category scenarios for testing according to actual needs, and the test results obtained have direct evaluation significance for the GNSS antenna under test.

[0052] For example, the GNSS antenna under test and a standard GNSS antenna can be placed in the same actual application scenario to perform a performance test on the GNSS antenna under test. Specifically, the GNSS antenna performance test system can be set up in any one or all of the aforementioned first, second, and third scenarios for testing. The following describes the process by which the GNSS antenna performance test system obtains the antenna performance of the antenna under test 102.

[0053] In this embodiment, the standard GNSS antenna 101 is used to receive a first GNSS satellite signal from a GNSS satellite; the GNSS antenna under test 102 is used to receive a second GNSS satellite signal from the GNSS satellite;

[0054] The first GNSS radio frequency circuit 201 is configured to obtain a first IQ digital signal according to the first GNSS satellite signal;

[0055] The second GNSS radio frequency circuit 202 is configured to obtain a second IQ digital signal according to the second GNSS satellite signal;

[0056] The GNSS baseband processing and analysis circuit 203 is configured to obtain a first C / N0 sequence based on the first IQ digital signal and a second C / N0 sequence based on the second IQ digital signal; and determine the gain and / or pattern performance of the GNSS antenna under test based on the first C / N0 sequence and the second C / N0 sequence.

[0057] It should be noted that since there are many types of GNSS satellites, the C / N0 values ​​of the analyzed GNSS satellites can be first categorized and sorted by satellite number. The C / N0 value represents the ratio of carrier power to noise power spectral density, expressed in dBHz, and can be referred to as the carrier-to-noise ratio. Satellites with C / N0 values ​​greater than a first preset carrier-to-noise ratio threshold are then selected for evaluating the gain of the GNSS antenna under test. For example, the first preset carrier-to-noise ratio threshold is 40 dBHz. The first preset carrier-to-noise ratio threshold can also be other values ​​and is not limited here.

[0058] In this embodiment, a corresponding local sky map can be obtained based on the first C / N0 sequence and the second C / N0 sequence, and the directional pattern performance of the GNSS antenna under test can be determined based on the obtained local sky map. The process of obtaining the gain of the GNSS antenna under test is described below.

[0059] In one embodiment, the GNSS baseband processing and analysis circuit 203 is further configured to determine whether each C / N0 value in the second C / N0 sequence is greater than a first preset carrier-to-noise ratio threshold; and if so, determine the gain of the GNSS antenna under test based on the C / N0 difference between the first C / N0 sequence and the second C / N0 sequence.

[0060] Exemplarily, if the first preset carrier-to-noise ratio threshold is 40 dBHz, then the relevant data of GNSS satellites with C / N0 values ​​greater than 40 dBHz are selected to evaluate the gain of the GNSS antenna under test.

[0061] In one embodiment, the GNSS baseband processing and analysis circuit 203 is further configured to generate a first C / N0 curve and a second C / N0 curve according to the first C / N0 sequence and the second C / N0 sequence, respectively; and determine the C / N0 difference according to the first C / N0 curve and the second C / N0 curve.

[0062] In this embodiment, the C / N0 values ​​of the same GNSS satellite obtained by the tested GNSS antenna 102 and the standard GNSS antenna 101 are plotted and compared based on Coordinated Universal Time (UTC) seconds. The number of satellites for which the C / N0 value plots are to be obtained can be selected as needed, thereby obtaining multiple sets of C / N0 value comparison curves.

[0063] See also Figure 2 and Figure 3 , Figure 2 To use the above steps, the first C / N0 curve of BeiDou C03 satellite is obtained based on the standard GNSS antenna. Figure 3 In order to adopt the above steps, the second C / N0 curve of BeiDou C03 satellite is obtained based on the GNSS antenna under test. Figure 2 and Figure 3 The C / N0 difference between the tested GNSS antenna and the standard GNSS antenna is shown. The average difference is approximately 2 dBhz. Under the same conditions, this difference can be equivalent to the gain difference between the two tested GNSS antennas and the standard GNSS antenna.

[0064] In one embodiment, the GNSS baseband processing and analysis circuit 203 is further used to determine multiple comparison satellites of the GNSS satellite, obtain the C / N0 difference of each comparison satellite, and determine the arithmetic mean of the C / N0 differences of each comparison satellite as the total gain difference of the GNSS antenna under test; and determine the gain of the GNSS antenna under test based on the gain of the standard GNSS antenna and the total gain difference.

[0065] It should be noted that, considering the characteristics of the GNSS antenna's orientation and gain, other GNSS satellites within the same navigation system can be selected as comparison satellites. For example, in the BeiDou system, satellites other than BeiDou C03 can be used as comparison satellites. The number of comparison satellites can be selected as needed. The arithmetic mean of the C / N0 differences among the selected comparison satellites is equivalent to the total antenna gain difference. The final gain obtained by adding or subtracting the total antenna gain difference based on the known gain parameters of a standard GNSS antenna is used as the gain of the GNSS antenna under test.

[0066] In one embodiment, the GNSS baseband processing and analysis circuit 203 is further configured to determine each first comparison C / N0 sequence based on each first comparison IQ digital signal, and determine each second comparison C / N0 sequence based on each second comparison IQ digital signal; and determine a C / N0 difference between each first comparison C / N0 sequence and each second comparison C / N0 sequence as a C / N0 difference of the corresponding comparison satellite.

[0067] Among them, each first comparison IQ digital signal is obtained by the first GNSS radio frequency circuit according to each first comparison satellite signal, each second comparison IQ digital signal is obtained by the second GNSS radio frequency circuit according to each second comparison satellite signal, each first comparison satellite signal is received by the standard GNSS antenna from each comparison satellite, and each second comparison satellite signal is received by the tested GNSS antenna from each comparison satellite.

[0068] In this way, the C / N0 difference of each comparison satellite can be obtained, and the gain of the measured GNSS antenna can be determined based on the arithmetic mean of the C / N0 differences of each comparison satellite, thereby improving the accuracy of the gain of the measured GNSS antenna.

[0069] The following describes the process of obtaining the directional pattern performance of the GNSS antenna under test.

[0070] It's understandable that a typical antenna's radiation pattern is typically spherical, with the unevenness of the spherical surface reflecting the antenna's gain in that direction. Anechoic chamber testing can generally provide a rough estimate of the antenna's radiation pattern. This is because microwave anechoic chamber testing involves rotating the antenna multiple times, obtaining measurements in multiple planes. Software processing then overlays and connects these measurements to create a spherical radiation pattern. The angle of each rotation determines the resolution of the antenna's radiation pattern.

[0071] In addition, since the GNSS antenna is facing the sky when working to obtain the best receiving capability, the directional pattern of the GNSS antenna is usually hemispherical, which is significantly different from antennas for other purposes. The directional pattern of the GNSS antenna is ultimately reflected in the power value of the initial signal transmitted by GNSS satellites at different positions under the real starry sky. Based on this, a method for testing the equivalent GNSS antenna directional pattern is proposed in this embodiment. The GNSS antenna under test is placed under the real starry sky, and the GNSS satellite signals within a certain time period are received. The C / N0 value of the GNSS satellite at each moment (in units of 1 second) is analyzed and obtained, and a GNSS antenna star map is accumulated. The GNSS antenna star map is used instead of the GNSS directional pattern performance to evaluate the performance. It has obvious advantages. By observing the size distribution characteristics of the C / N0 value, the difference in the GNSS antenna receiving GNSS satellite signals in various directions can be evaluated.

[0072] In one embodiment, the GNSS baseband processing and analysis circuit 203 is further configured to obtain a first azimuth sequence and a first elevation sequence according to the first IQ digital signal, and obtain a first local star map of the standard GNSS antenna according to the first azimuth sequence, the first elevation sequence, and the first C / N0 sequence;

[0073] acquiring a second azimuth sequence and a second elevation sequence according to the second IQ digital signal, and acquiring a second local star map of the GNSS antenna under test according to the second azimuth sequence, the second elevation sequence, and the second C / N0 sequence;

[0074] The directional pattern performance of the measured GNSS antenna is determined according to the first local star map and the second local star map.

[0075] In this embodiment, the first azimuth angle sequence, the first elevation angle sequence, and the first C / N0 sequence may be an azimuth angle time sequence, an elevation angle time sequence, and a C / N0 time sequence arranged in chronological order within a preset time period. The second azimuth angle sequence, the second elevation angle sequence, and the second C / N0 sequence may be an azimuth angle time sequence, an elevation angle time sequence, and a C / N0 time sequence arranged in chronological order within the same preset time period.

[0076] In one embodiment, the GNSS baseband processing and analysis circuit 203 is further configured to determine a test validity period based on the operating speed and orbital parameters of the GNSS satellite, and determine an azimuth angle change value and an elevation angle change value of the GNSS satellite within the test validity period;

[0077] Dividing the test scene space into a plurality of local space regions according to the azimuth angle change value and the elevation angle change value;

[0078] obtaining a C / N0 average value of the standard GNSS antenna in each local space region according to the first azimuth angle sequence, the first elevation angle sequence, and the first C / N0 sequence, marking the C / N0 average value of the standard GNSS antenna in each local space region on the corresponding local space region, to obtain the first local star map;

[0079] Obtain a C / N0 average value of the measured GNSS antenna in each local spatial area according to the second azimuth sequence, the second elevation sequence, and the second C / N0 sequence, mark the C / N0 average value of the measured GNSS antenna in each local spatial area in the corresponding local spatial area, and obtain the second local star map.

[0080] In one embodiment, the GNSS baseband processing and analysis circuit 203 is further configured to use the horizon as a 0-degree line, a zenith directly above the standard GNSS antenna or the GNSS antenna under test as the zenith, determine an elevation angle range of 90° between the 0-degree line and the standard GNSS antenna or the GNSS antenna under test, and determine an azimuth angle range of 360°.

[0081] The azimuth angle range is divided into N azimuth angle division areas according to the azimuth angle change value, and the elevation angle range corresponding to each azimuth angle division area is divided into M elevation angle division areas according to the elevation angle change value, thereby obtaining N×M local space areas.

[0082] For example, in the selected test scenario (preferably an open field scenario), the elevation angle range is 90°, with the horizon representing the 0-degree line and the zenith directly above the GNSS antenna under test or the standard antenna. Based on the estimated test duration of 30 minutes, based on GNSS satellite operating speed and orbital parameters, most GNSS satellites experience elevation variations greater than 10° or azimuth variations greater than 15°. Therefore, the azimuth angle is divided into 15-degree zones, resulting in 24 azimuth zones within a total range of 360 degrees. The elevation angle is divided into 10-degree zones, resulting in 9 elevation zones within a total range of 90 degrees. Using the aforementioned azimuth and elevation division method, a total of 216 zones are obtained. The more zones divided, the higher the resolution of the resulting GNSS sky map; the fewer zones divided, the lower the resolution of the resulting GNSS sky map. In this embodiment, the sky map is divided into 216 zones, based on a single test duration of 30 minutes. Other combinations are possible in other situations and are not limiting.

[0083] In one embodiment, the GNSS baseband processing and analysis circuit 203 is further used to draw a color-changing mark in the corresponding local spatial area according to the C / N0 average value of the standard GNSS antenna in each local spatial area; and draw a color-changing mark in the corresponding local spatial area according to the C / N0 average value of the tested GNSS antenna in each local spatial area; wherein the color-changing mark changes according to a preset color gradient sequence as the C / N0 average value of the standard GNSS antenna in each local spatial area or the C / N0 average value of the tested GNSS antenna in each local spatial area increases.

[0084] It should be noted that the preset color gradient sequence can be a gradient sequence of light and dark shades of a single color, or a gradient sequence of light and dark shades between multiple colors, without limitation. For example, a gradient sequence of light and dark shades of gray, or a gradient sequence of light and dark shades between blue, green, and yellow.

[0085] In one embodiment, the GNSS baseband processing and analysis circuit 203 is further configured to determine, based on the first azimuth angle sequence and the first elevation angle sequence, a first C / N0 subsequence of the first C / N0 sequence located in each local spatial region, determine at least one first target C / N0 value greater than a second preset carrier-to-noise ratio threshold in each first C / N0 subsequence, and calculate an average C / N0 value of the standard GNSS antenna in each local spatial region based on the at least one first target C / N0 value;

[0086] Determine, based on the second azimuth sequence and the second elevation sequence, a second C / N0 subsequence of the second C / N0 sequence located in each local spatial area, determine at least one second target C / N0 value greater than the second preset carrier-to-noise ratio threshold in each second C / N0 subsequence, and calculate, based on the at least one second target C / N0 value, a C / N0 average value of the measured GNSS antenna in each local spatial area.

[0087] In this embodiment, based on theories and practical experience such as free space attenuation, thermal noise theory, and satellite transmit power, the GNSS receiver resolves the lowest C / N0 value of the GNSS satellite to be 21 dBHz. The second preset carrier-to-noise ratio threshold can be set to 21 dBHz, or other values, which are not limited here.

[0088] In this embodiment, the C / N0 average value of the standard GNSS antenna in each local spatial area can be calculated according to the following formula: the sum of at least one first target C / N0 value ÷ the number of first target C / N0 values.

[0089] In this embodiment, the C / N0 average value of the measured GNSS antenna in each local spatial area can be calculated according to the following formula: the sum of at least one second target C / N0 value ÷ the number of second target C / N0 values.

[0090] For example, the Beidou navigation system can be categorized by orbit: geostationary satellites (GEO), inclined geosynchronous satellites (IGSO), and medium Earth orbits (MEO). GEO satellites maintain a constant projected position on Earth; IGSO satellites have an orbital period that matches Earth's rotation, with their subsatellite trajectory forming a figure-eight pattern. MEO satellites have a subsatellite trajectory that continuously draws wavy lines.

[0091] In one example, according to the above C / N0 mean value calculation formula and the sky map division scheme, the C / N0 values ​​of the GEO satellites received by the standard GNSS antenna and the GNSS antenna under test are written into the corresponding local division areas, and the following are obtained: Figure 4 and Figure 5 . Figure 4 The first local sky map is generated based on the C / N0 values ​​of GEO satellites obtained by a standard GNSS antenna. Figure 5 The second local sky map is generated based on the C / N0 value of the GEO satellite obtained by the GNSS antenna under test. Figure 4 and Figure 5 As shown in the figure, the black area indicates that no valid C / N0 value was analyzed in this area within the effective test time. Figure 4 and Figure 5 The average C / N0 value of the standard GNSS antenna in the azimuth angle [180,195] region is 4dBHz higher than that of the tested GNSS antenna in the azimuth angle [180,195] region; the average C / N0 value of the standard GNSS antenna in the azimuth angle [120,135] region is basically the same as that of the tested GNSS antenna in the azimuth angle [120,135]. Figure 4 and Figure 5 It can be seen that there is a significant difference in gain between the standard GNSS antenna and the tested GNSS antenna in different directions, which reflects the directivity of the GNSS antenna.

[0092] In another example, according to the above C / N0 mean value calculation formula and star map division method, the C / N0 values ​​of the Beidou MEO satellites received by the standard GNSS antenna and the tested GNSS antenna are written into the corresponding division areas, respectively, to obtain Figure 6 and Figure 7 . Figure 6 The first local sky map is generated based on the C / N0 values ​​of BeiDou MEO satellites obtained by a standard GNSS antenna. Figure 7 The second local sky map is generated based on the C / N0 value of the BeiDou MEO satellite obtained by the GNSS antenna under test. Figure 6 and Figure 7 As shown in the figure, the black area indicates that no valid C / N0 value was analyzed in this area during the test period. Figure 6 and Figure 7 The C / N0 average value of the tested GNSS antenna for BeiDou signal reception is significantly lower than that of the standard GNSS antenna. For example, the average value of the three blocks at the azimuth angle of [195, 210] for the standard GNSS antenna is 47.7 dBHz, while the average value of the three blocks at the azimuth angle of [195, 210] for the tested GNSS antenna is 43.0 dBHz, resulting in a difference of 4.7 dBHz between the three blocks. The differences in elevation angles are 2.7 dBHz, 4.7 dBHz, and 6.7 dBHz, respectively. This indicates that in this azimuth range, the pattern gain of the tested GNSS antenna at high elevation angles is significantly lower than that of the standard GNSS antenna, and its pattern is flatter. This comparison indicates that the tested GNSS antenna has poor BeiDou signal reception capabilities.

[0093] In another example, according to the above C / N0 mean value calculation formula and the star map division method, the C / N0 values ​​of GPS satellites received by the standard GNSS antenna and the tested GNSS antenna are written into the corresponding division areas, respectively, to obtain Figure 8 and Figure 9 . Figure 8 The first local sky map is generated based on the C / N0 values ​​of GPS satellites obtained by a standard GNSS antenna. Figure 9 The second local sky map is generated based on the C / N0 value of the GPS satellite obtained by the GNSS antenna under test. Figure 8 and Figure 9 As shown in the figure, the black area indicates that no valid C / N0 value was analyzed in this area during the test period. Figure 8 and Figure 9 As shown in Figure 2, the C / N0 average value of the GPS signal received by the tested GNSS antenna is slightly lower than the C / N0 average value of the GPS signal received by the standard GNSS antenna. Figure 8 and Figure 9 As shown, the standard GNSS antenna has an average of 42.6 dBHz for the six azimuth angles [210, 225], while the tested GNSS antenna has an average of 42.9 dBHz for the three azimuth angles [210, 225], with a difference of -0.3 dBHz across the six averages. Within this azimuth range, the tested GNSS antenna significantly outperforms the standard antenna in the elevation angle range [10, 20]; however, it is slightly inferior to the standard antenna in the elevation angle range [20, 60]. This indicates that the tested GNSS antenna has a flat radiation pattern, while the standard GNSS antenna has a prominent radiation pattern at high elevation angles. This comparison indicates that the tested GNSS antenna's GPS reception performance is slightly inferior to that of the tested GNSS antenna.

[0094] In one embodiment, the GNSS baseband processing and analysis circuit 203 is further configured to calculate a test period based on an operating period of the GNSS satellite and the test validity period;

[0095] Obtaining a first panoramic starry sky image and a second panoramic starry sky image of the standard GNSS antenna and the GNSS antenna under test respectively during the test period;

[0096] The directional pattern performance of the measured GNSS antenna is determined according to the first panoramic star map and the second panoramic star map.

[0097] In this embodiment, a single test lasts at least 30 minutes. Within 30 minutes, the elevation angle of most GNSS satellites changes by more than 10° or the azimuth angle changes by more than 15 degrees, satisfying the aforementioned division of local spatial regions in the star map. The longest MEO satellite cycle in a GNSS system is approximately 14 hours. A single acquisition time of more than 15 hours can yield a complete panoramic star map.

[0098] like Figure 10 As shown in the figure, the azimuth angle [315, 15] region of the test scene is blocked by obstacles. In the panoramic star map, the high and low C / N0 values ​​are more fully distributed, making it easier to compare the signal reception performance of the tested GNSS antennas.

[0099] See also Figure 11 , Figure 11 and Figure 1 The difference is that, in addition to the first GNSS RF circuit 201, the second GNSS RF circuit 202, and the GNSS baseband processing and analysis circuit 203, the GNSS reception and processing device 200 also includes a GNSS RF signal acquisition circuit 204, a first SD memory card 205, a second SD memory card 206, an RTC circuit 207, a lithium battery circuit 208, a TCXO circuit 209, and a clock synchronization circuit 2010. The GNSS baseband processing and analysis circuit 203 is further connected to the GNSS RF signal acquisition circuit 204, the first SD memory card 205, and the RTC circuit 207, respectively. The GNSS RF signal acquisition circuit 204 is also connected to the first GNSS RF circuit 201, the second GNSS RF circuit 202, and the second SD memory card 206, and the TCXO circuit 209 is connected to the clock synchronization circuit 2010.

[0100] It's understood that the theoretical GNSS signal spectrum, which includes the low-frequency band of 1176.45MHz-1278.75MHz and the high-frequency band of 1561.098MHz-1602MHz, is a dedicated spectrum. Without permission, no organization or individual may transmit GNSS signals within the same spectrum. In practice, strong interference within the GNSS spectrum band is often detected. The source of these interference signals is unknown. This embodiment further provides a solution for detecting interference signals.

[0101] In one embodiment, the GNSS RF signal acquisition circuit 204 is configured to receive an acquisition instruction from the GNSS baseband processing and analysis circuit, acquire the first IQ digital signal according to the acquisition instruction, and acquire a third C / N0 sequence according to the first IQ digital signal; if a third target C / N0 value less than a third preset carrier-to-noise ratio threshold exists in the third C / N0 sequence, perform an FFT transform on the first IQ digital signal to generate a first spectrum diagram, and determine whether an interference signal exists in the GNSS frequency band based on the first spectrum diagram and a pre-acquired standard spectrum diagram.

[0102] Exemplarily, the spectrum signal of GNSS is monitored synchronously to determine whether there is interference and whether the test results are valid. After receiving the acquisition instruction issued by the GNSS baseband processing and analysis circuit 203, the GNSS RF signal acquisition circuit 204 starts to acquire the first IQ digital signal of the first GNSS RF circuit 201, which has a duration of 10ms and is synchronously stored in the second SD memory card 206. After receiving the acquisition instruction from the GNSS baseband processing and analysis circuit 203, the acquisition instruction is issued once per second according to the UTC time. During subsequent processing, if it is found that the C / N0 value analyzed by the standard GNSS antenna at a certain moment is significantly lower than expected, that is, lower than the third preset carrier-to-noise ratio threshold, the 10ms data at the corresponding moment is selected for FFT transformation to generate a first spectrum diagram. The first spectrum diagram and the standard spectrum diagram can be observed to determine whether there is a difference in the GNSS frequency band. If there is a difference, it means that there is an interference signal. If there is no difference, it means that there is no interference signal.

[0103] In one embodiment, the GNSS RF signal acquisition circuit 204 is further configured to determine that the gain and / or pattern performance of the GNSS antenna under test is invalid if the interference signal exists.

[0104] Please refer again Figure 11 , the antenna device further includes a metal shielding plate 103 and a rainproof component 104;

[0105] The metal shielding plate 103 is disposed at the bottom of the standard GNSS antenna 101 and the tested GNSS antenna 102;

[0106] The rainproof component 104 is used to shield the standard GNSS antenna 101 and the GNSS antenna under test 102 .

[0107] Exemplarily, the metal shielding plate 103 may be a metal steel plate to shield interference signals from below. The rainproof component 104 may be a rain cover to prevent rain from wetting the standard GNSS antenna 101 and the GNSS antenna under test 102.

[0108] The size of metal shielding plate 103 can be adjusted based on the GNSS antenna specifications. For example, it can be set to 50 cm x 50 cm to cover both the GNSS antenna under test and the standard GNSS antenna. Metal shielding plate 103 blocks the GNSS antenna under test and the standard GNSS antenna from receiving reflected signals below the antenna base, resulting in a hemispherical antenna pattern facing the sky.

[0109] Please refer again Figure 11 , the GNSS receiving and processing device 200 further includes: a first SD memory card 205;

[0110] The GNSS baseband processing and parsing circuit 203 is configured to obtain first NMEA information according to the first IQ digital signal and obtain second NMEA information according to the second IQ digital signal;

[0111] The first SD memory card 205 is used to store the first NMEA information and the second NMEA information.

[0112] In this embodiment, the first NMEA information and the second NMEA information are information obtained by parsing according to the satellite protocol, including various operating parameters of the GNSS satellite. Based on the first NMEA information and the second NMEA information, the first azimuth sequence, the first elevation sequence and the first C / N0 sequence, the second azimuth sequence, the second elevation sequence and the second C / N0 sequence can be obtained respectively. The acquisition method can adopt the existing acquisition method, which will not be repeated here.

[0113] Please refer again Figure 11 , the GNSS receiving and processing device 200 further includes: a second SD memory card 206;

[0114] The second SD memory card is used to store the first IQ digital signal and the second IQ digital signal.

[0115] In this embodiment, the first IQ digital signal and the second IQ digital signal are binary coded data including 0 and 1, respectively.

[0116] Please refer again Figure 11 , the GNSS receiving and processing device 200 further includes:

[0117] RTC circuit 207, used to calibrate the GNSS baseband processing and analysis circuit using UTC time;

[0118] The lithium battery circuit 208 is used to supply power to the first GNSS radio frequency circuit 201 , the second GNSS radio frequency circuit 202 , and the GNSS baseband processing and analysis circuit 203 .

[0119] In this embodiment, the RTC circuit 207 provides a local clock, which is calibrated with UTC time before each test. The lithium battery circuit 208 provides power to the system, converting it into the voltage source required by the system and working independently.

[0120] Please refer again Figure 11 , the GNSS receiving and processing device 200 further includes:

[0121] TCXO circuit 209, used to provide a reference clock to the clock synchronization circuit 2010;

[0122] The clock synchronization circuit 2010 is used to provide the reference clock to the first GNSS radio frequency circuit, the second GNSS radio frequency circuit, the GNSS baseband processing and analysis circuit, and the GNSS radio frequency signal acquisition circuit respectively.

[0123] Exemplarily, the TCXO circuit 209 provides a reference clock for the clock synchronization circuit 2010. The clock synchronization circuit 2010 generates four reference clocks which are provided to the first GNSS RF circuit 201, the second GNSS RF circuit 202, the GNSS RF signal acquisition circuit 204, and the GNSS baseband processing and analysis circuit 203 as their reference clock sources.

[0124] Please refer again Figure 11 , the GNSS receiving and processing device 200 further includes:

[0125] The metal shielding box 2011 , the first GNSS radio frequency circuit 201 , the second GNSS radio frequency circuit 202 , and the GNSS baseband processing and analysis circuit 203 are located in a shielding cavity of the metal shielding box 2011 .

[0126] Furthermore, other circuits of the GNSS receiving and processing device 200 , the first SD memory card, and the second SD memory card are also located in the shielding cavity of the metal shielding box 2011 .

[0127] In this embodiment, the metal shielding box 2011 blocks external interference signals and prevents the standard GNSS antenna 101 and the tested GNSS antenna 102 from receiving interference signals generated by the circuit in the metal shielding box 2011 .

[0128] The GNSS antenna performance testing system provided in this embodiment includes a standard GNSS antenna for receiving a first GNSS satellite signal from a GNSS satellite; a GNSS antenna under test for receiving a second GNSS satellite signal from a GNSS satellite; a first GNSS radio frequency circuit for obtaining a first IQ digital signal based on the first GNSS satellite signal; a second GNSS radio frequency circuit for obtaining a second IQ digital signal based on the second GNSS satellite signal; a GNSS baseband processing and analysis circuit for obtaining a first C / N0 sequence based on the first IQ digital signal and a second C / N0 sequence based on the second IQ digital signal; and determining the gain and / or radiation pattern performance of the GNSS antenna under test based on the first C / N0 sequence and the second C / N0 sequence. Thus, the system is low-cost and easy to implement GNSS antenna performance testing under a real starry sky. By placing the GNSS antenna under test in a real starry sky environment and application scenario for testing, the performance of the GNSS antenna under test can be accurately evaluated, thereby improving the evaluation effect of the GNSS antenna under test performance.

[0129] Example 2

[0130] In addition, an embodiment of the present application provides a GNSS antenna performance testing method, which is applied to the GNSS antenna performance testing system provided in Example 1.

[0131] See also Figure 12 , GNSS antenna performance test methods include:

[0132] Step S1201: receiving a first GNSS satellite signal from a GNSS satellite;

[0133] Step S1202, receiving a second GNSS satellite signal from the GNSS satellite;

[0134] Step S1203: Acquire a first IQ digital signal according to the first GNSS satellite signal;

[0135] Step S1204: Acquire a second IQ digital signal according to the second GNSS satellite signal;

[0136] Step S1205: Acquire a first C / N0 sequence according to the first IQ digital signal, and acquire a second C / N0 sequence according to the second IQ digital signal;

[0137] Step S1206: Determine the gain and / or pattern performance of the GNSS antenna under test according to the first C / N0 sequence and the second C / N0 sequence.

[0138] In one embodiment, determining the gain of the GNSS antenna under test according to the first C / N0 sequence and the second C / N0 sequence includes:

[0139] Determining whether each C / N0 value in the second C / N0 sequence is greater than a first preset carrier-to-noise ratio threshold;

[0140] If yes, the gain of the measured GNSS antenna is determined according to the C / N0 difference between the first C / N0 sequence and the second C / N0 sequence.

[0141] In one embodiment, taking the C / N0 difference includes:

[0142] Generate a first C / N0 curve and a second C / N0 curve according to the first C / N0 sequence and the second C / N0 sequence respectively;

[0143] The C / N0 difference is determined according to the first C / N0 curve and the second C / N0 curve.

[0144] In one embodiment, the method further comprises:

[0145] Determining a plurality of comparison satellites of the GNSS satellite, obtaining a C / N0 difference of each comparison satellite, and determining an arithmetic mean of the C / N0 differences of each comparison satellite as a total gain difference of the measured GNSS antenna;

[0146] The gain of the GNSS antenna under test is determined according to the gain of the standard GNSS antenna and the total gain difference.

[0147] In one embodiment, obtaining the C / N0 difference of each comparison satellite includes:

[0148] Determine each first comparison C / N0 sequence according to each first comparison IQ digital signal, and determine each second comparison C / N0 sequence according to each second comparison IQ digital signal;

[0149] Determine the C / N0 difference between each first comparison C / N0 sequence and each second comparison C / N0 sequence as the C / N0 difference of the corresponding comparison satellite;

[0150] Among them, each first comparison IQ digital signal is obtained by the first GNSS radio frequency circuit according to each first comparison satellite signal, each second comparison IQ digital signal is obtained by the second GNSS radio frequency circuit according to each second comparison satellite signal, each first comparison satellite signal is received by the standard GNSS antenna from each comparison satellite, and each second comparison satellite signal is received by the tested GNSS antenna from each comparison satellite.

[0151] In one embodiment, determining the directional pattern performance of the GNSS antenna under test according to the first C / N0 sequence and the second C / N0 sequence includes:

[0152] Acquire a first azimuth sequence and a first elevation sequence according to the first IQ digital signal, and acquire a first local star map of the standard GNSS antenna according to the first azimuth sequence, the first elevation sequence, and the first C / N0 sequence;

[0153] acquiring a second azimuth sequence and a second elevation sequence according to the second IQ digital signal, and acquiring a second local star map of the GNSS antenna under test according to the second azimuth sequence, the second elevation sequence, and the second C / N0 sequence;

[0154] The directional pattern performance of the measured GNSS antenna is determined according to the first local star map and the second local star map.

[0155] In one embodiment, the method further comprises:

[0156] Determining a test validity period according to the operating speed and orbital parameters of the GNSS satellite, and determining an azimuth angle change value and an elevation angle change value of the GNSS satellite within the test validity period according to the test validity period;

[0157] Dividing the test scene space into a plurality of local space regions according to the azimuth angle change value and the elevation angle change value;

[0158] Acquiring the first local star map includes:

[0159] obtaining a C / N0 average value of the standard GNSS antenna in each local space region according to the first azimuth angle sequence, the first elevation angle sequence, and the first C / N0 sequence, marking the C / N0 average value of the standard GNSS antenna in each local space region on the corresponding local space region, to obtain the first local star map;

[0160] Acquiring the second local star map includes:

[0161] Obtain a C / N0 average value of the measured GNSS antenna in each local spatial area according to the second azimuth sequence, the second elevation sequence, and the second C / N0 sequence, mark the C / N0 average value of the measured GNSS antenna in each local spatial area in the corresponding local spatial area, and obtain the second local star map.

[0162] In one embodiment, dividing the test scene space into a plurality of local spatial regions according to the azimuth angle change value and the elevation angle change value includes:

[0163] The horizon is defined as the 0-degree line, and the area directly above the standard GNSS antenna or the GNSS antenna under test is defined as the zenith. The angle between the 0-degree line and the standard GNSS antenna or the GNSS antenna under test is defined as the elevation angle range, and the angle of 360 degrees is defined as the azimuth angle range.

[0164] The azimuth angle range is divided into N azimuth angle division areas according to the azimuth angle change value, and the elevation angle range corresponding to each azimuth angle division area is divided into M elevation angle division areas according to the elevation angle change value, thereby obtaining N×M local space areas.

[0165] In one embodiment, the method further comprises:

[0166] Drawing a color change mark in the corresponding local space area according to the C / N0 average value of the standard GNSS antenna in each local space area;

[0167] Drawing a color-changing mark in the corresponding local spatial area according to the C / N0 average value of the GNSS antenna under test in each local spatial area;

[0168] The color-changing mark changes in a preset color gradient sequence as the C / N0 average value of the standard GNSS antenna in each local spatial area or the C / N0 average value of the tested GNSS antenna in each local spatial area increases.

[0169] In one embodiment, obtaining the C / N0 mean value of the standard GNSS antenna in each local spatial area according to the first azimuth angle sequence, the first elevation angle sequence, and the first C / N0 sequence includes:

[0170] determining, based on the first azimuth angle sequence and the first elevation angle sequence, a first C / N0 subsequence of the first C / N0 sequence located in each local spatial area, determining at least one first target C / N0 value greater than a second preset carrier-to-noise ratio threshold in each first C / N0 subsequence, and calculating a C / N0 average value of the standard GNSS antenna in each local spatial area based on the at least one first target C / N0 value;

[0171] The obtaining, according to the second azimuth angle, the second elevation angle, and the second C / N0 sequence, a C / N0 average value of the measured GNSS antenna in each local spatial area includes:

[0172] Determine, based on the second azimuth sequence and the second elevation sequence, a second C / N0 subsequence of the second C / N0 sequence located in each local spatial area, determine at least one second target C / N0 value greater than the second preset carrier-to-noise ratio threshold in each second C / N0 subsequence, and calculate, based on the at least one second target C / N0 value, a C / N0 average value of the measured GNSS antenna in each local spatial area.

[0173] In one embodiment, the method further comprises:

[0174] Calculating a test period based on the operating period of the GNSS satellite and the test validity period;

[0175] Obtaining a first panoramic starry sky image and a second panoramic starry sky image of the standard GNSS antenna and the GNSS antenna under test respectively during the test period;

[0176] The directional pattern performance of the measured GNSS antenna is determined according to the first panoramic star map and the second panoramic star map.

[0177] In one embodiment, the method further comprises:

[0178] Acquire the first IQ digital signal according to the acquisition instruction, and acquire a third C / N0 sequence according to the first IQ digital signal;

[0179] If there is a third target C / N0 value less than a third preset carrier-to-noise ratio threshold in the third C / N0 sequence, the first IQ digital signal is FFT transformed to generate a first spectrum diagram, and it is determined whether there is an interference signal in the GNSS frequency band based on the first spectrum diagram and the pre-acquired standard spectrum diagram.

[0180] In one embodiment, the method further comprises:

[0181] If the interference signal exists, it is determined that the gain and / or pattern performance of the GNSS antenna under test is invalid.

[0182] The GNSS antenna performance testing method provided in this embodiment can implement the corresponding functions of the GNSS antenna performance testing system provided in Example 1 and achieve the same technical effects. To avoid repetition, it will not be described here.

[0183] The GNSS antenna performance testing method provided in this embodiment is low-cost and easy to implement GNSS antenna performance testing under a real starry sky. By setting the GNSS antenna under test in a real starry sky environment and application scenario for testing, the performance of the GNSS antenna under test can be accurately evaluated, thereby improving the evaluation effect of the performance of the GNSS antenna under test.

[0184] Example 3

[0185] In addition, an embodiment of the present application provides a GNSS antenna performance testing device.

[0186] See also Figure 13 , the GNSS antenna performance testing device 1300 includes:

[0187] The first receiving module 1301 is configured to receive a first GNSS satellite signal from a GNSS satellite;

[0188] A second receiving module 1302 is configured to receive a second GNSS satellite signal from the GNSS satellite;

[0189] A first acquisition module 1303 is configured to acquire a first IQ digital signal according to the first GNSS satellite signal;

[0190] A second acquisition module 1304 is configured to acquire a second IQ digital signal according to the second GNSS satellite signal;

[0191] A third acquisition module 1305 is configured to acquire a first C / N0 sequence according to the first IQ digital signal, and acquire a second C / N0 sequence according to the second IQ digital signal;

[0192] The determination module 1306 is configured to determine the gain and / or pattern performance of the GNSS antenna under test according to the first C / N0 sequence and the second C / N0 sequence.

[0193] The electronic device provided in this embodiment can implement the GNSS antenna performance testing method provided in Example 2, and will not be described again here to avoid repetition.

[0194] Example 4

[0195] The present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the GNSS antenna performance testing method provided in Example 2 is implemented.

[0196] In this embodiment, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0197] The computer-readable storage medium provided in this embodiment can implement the GNSS antenna performance testing method provided in Example 2, and will not be described again here to avoid repetition.

[0198] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or terminal comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or terminal comprising the element.

[0199] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in each embodiment of the present application.

[0200] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A GNSS antenna performance test system, characterized in that: include: An antenna device and a GNSS receiving and processing device, wherein the antenna device includes a standard GNSS antenna and a GNSS antenna under test, and the GNSS receiving and processing device includes a first GNSS radio frequency circuit, a second GNSS radio frequency circuit, and a GNSS baseband processing and analysis circuit; The standard GNSS antenna is used to receive a first GNSS satellite signal from a GNSS satellite; The GNSS antenna under test is used to receive a second GNSS satellite signal from the GNSS satellite; The first GNSS radio frequency circuit is configured to obtain a first IQ digital signal according to the first GNSS satellite signal; The second GNSS radio frequency circuit is configured to obtain a second IQ digital signal according to the second GNSS satellite signal; The GNSS baseband processing and analysis circuit is configured to obtain a first C / N0 sequence based on the first IQ digital signal and a second C / N0 sequence based on the second IQ digital signal; and determine the gain and / or pattern performance of the GNSS antenna under test based on the first C / N0 sequence and the second C / N0 sequence; The GNSS baseband processing and analysis circuit is further configured to obtain a first azimuth sequence and a first elevation sequence according to the first IQ digital signal, and obtain a first local star map of the standard GNSS antenna according to the first azimuth sequence, the first elevation sequence, and the first C / N0 sequence; acquiring a second azimuth sequence and a second elevation sequence according to the second IQ digital signal, and acquiring a second local star map of the GNSS antenna under test according to the second azimuth sequence, the second elevation sequence, and the second C / N0 sequence; The directional pattern performance of the measured GNSS antenna is determined according to the first local star map and the second local star map.

2. The GNSS antenna performance test system according to claim 1, characterized in that: The GNSS baseband processing and analysis circuit is further configured to determine whether each C / N0 value in the second C / N0 sequence is greater than a first preset carrier-to-noise ratio threshold; and if so, determine the gain of the GNSS antenna under test based on a C / N0 difference between the first C / N0 sequence and the second C / N0 sequence.

3. The GNSS antenna performance test system according to claim 2, characterized in that: The GNSS baseband processing and analysis circuit is further configured to generate a first C / N0 curve and a second C / N0 curve according to the first C / N0 sequence and the second C / N0 sequence, respectively; and determine the C / N0 difference according to the first C / N0 curve and the second C / N0 curve.

4. The GNSS antenna performance test system according to claim 1, characterized in that: The GNSS baseband processing and analysis circuit is further configured to determine a plurality of comparison satellites of the GNSS satellite, obtain a C / N0 difference of each comparison satellite, and determine an arithmetic mean of the C / N0 differences of each comparison satellite as a total gain difference of the GNSS antenna under test; The gain of the GNSS antenna under test is determined according to the gain of the standard GNSS antenna and the total gain difference.

5. The GNSS antenna performance test system according to claim 4, characterized in that: The GNSS baseband processing and analysis circuit is further configured to determine each first comparison C / N0 sequence based on each first comparison IQ digital signal, and determine each second comparison C / N0 sequence based on each second comparison IQ digital signal; and determine the C / N0 difference between each first comparison C / N0 sequence and each second comparison C / N0 sequence as the C / N0 difference of the corresponding comparison satellite; Among them, each first comparison IQ digital signal is obtained by the first GNSS radio frequency circuit according to each first comparison satellite signal, each second comparison IQ digital signal is obtained by the second GNSS radio frequency circuit according to each second comparison satellite signal, each first comparison satellite signal is received by the standard GNSS antenna from each comparison satellite, and each second comparison satellite signal is received by the tested GNSS antenna from each comparison satellite.

6. The GNSS antenna performance test system according to claim 1, characterized in that: The GNSS baseband processing and analysis circuit is further used to determine a test effective time according to the operating speed and orbital parameters of the GNSS satellite, and determine an azimuth angle change value and an elevation angle change value of the GNSS satellite within the test effective time; Dividing the test scene space into a plurality of local space regions according to the azimuth angle change value and the elevation angle change value; obtaining a C / N0 average value of the standard GNSS antenna in each local space region according to the first azimuth angle sequence, the first elevation angle sequence, and the first C / N0 sequence, marking the C / N0 average value of the standard GNSS antenna in each local space region on the corresponding local space region, to obtain the first local star map; Obtain a C / N0 average value of the measured GNSS antenna in each local spatial area according to the second azimuth sequence, the second elevation sequence, and the second C / N0 sequence, mark the C / N0 average value of the measured GNSS antenna in each local spatial area in the corresponding local spatial area, and obtain the second local star map.

7. The GNSS antenna performance test system according to claim 6, characterized in that: The GNSS baseband processing and analysis circuit is further configured to use the horizon as the 0-degree line, a zenith directly above the standard GNSS antenna or the GNSS antenna under test, and a 90-degree angle between the 0-degree line and the standard GNSS antenna or the GNSS antenna under test as the elevation angle range, and 360 degrees as the azimuth angle range; The azimuth angle range is divided into N azimuth angle division areas according to the azimuth angle change value, and the elevation angle range corresponding to each azimuth angle division area is divided into M elevation angle division areas according to the elevation angle change value, thereby obtaining N×M local space areas.

8. The GNSS antenna performance test system according to claim 6, characterized in that: The GNSS baseband processing and analysis circuit is further used to draw a color-changing mark in the corresponding local spatial area according to the C / N0 average value of the standard GNSS antenna in each local spatial area; A color-changing mark is drawn in the corresponding local spatial area according to the C / N0 average value of the GNSS antenna under test in each local spatial area; wherein the color-changing mark changes according to a preset color gradient sequence as the C / N0 average value of the standard GNSS antenna in each local spatial area or the C / N0 average value of the GNSS antenna under test in each local spatial area increases.

9. The GNSS antenna performance test system according to claim 6, characterized in that: The GNSS baseband processing and analysis circuit is further configured to determine, based on the first azimuth angle sequence and the first elevation angle sequence, a first C / N0 subsequence of the first C / N0 sequence located in each local spatial region, determine at least one first target C / N0 value greater than a second preset carrier-to-noise ratio threshold in each first C / N0 subsequence, and calculate a C / N0 average value of the standard GNSS antenna in each local spatial region based on the at least one first target C / N0 value; Determine, based on the second azimuth sequence and the second elevation sequence, a second C / N0 subsequence of the second C / N0 sequence located in each local spatial area, determine at least one second target C / N0 value greater than the second preset carrier-to-noise ratio threshold in each second C / N0 subsequence, and calculate, based on the at least one second target C / N0 value, a C / N0 average value of the measured GNSS antenna in each local spatial area.

10. The GNSS antenna performance test system according to claim 6, characterized in that: The GNSS baseband processing and analysis circuit is further configured to calculate a test period based on the operating period of the GNSS satellite and the test validity period; Obtaining a first panoramic starry sky image and a second panoramic starry sky image of the standard GNSS antenna and the GNSS antenna under test respectively during the test period; The directional pattern performance of the measured GNSS antenna is determined according to the first panoramic star map and the second panoramic star map.

11. The GNSS antenna performance test system according to claim 1, characterized in that: The GNSS receiving and processing device further includes: The GNSS radio frequency signal acquisition circuit is configured to receive an acquisition instruction from the GNSS baseband processing and analysis circuit, acquire the first IQ digital signal according to the acquisition instruction, and acquire a third C / N0 sequence according to the first IQ digital signal; if a third target C / N0 value less than a third preset carrier-to-noise ratio threshold exists in the third C / N0 sequence, perform an FFT transform on the first IQ digital signal to generate a first spectrum diagram, and determine whether an interference signal exists within the GNSS frequency band based on the first spectrum diagram and a pre-acquired standard spectrum diagram.

12. The GNSS antenna performance test system according to claim 11, characterized in that: The GNSS radio frequency signal acquisition circuit is further configured to determine that the gain and / or directional pattern performance of the GNSS antenna under test is invalid if the interference signal exists.

13. The GNSS antenna performance test system according to claim 1, characterized in that: The antenna device also includes a metal shielding plate and a rainproof component; The metal shielding plate is arranged at the bottom of the standard GNSS antenna and the GNSS antenna under test; The rainproof component is used to shield the standard GNSS antenna and the GNSS antenna under test.

14. The GNSS antenna performance test system according to claim 1, characterized in that: The GNSS receiving and processing device further includes: a first SD memory card; The GNSS baseband processing and parsing circuit is configured to obtain first NMEA information based on the first IQ digital signal and obtain second NMEA information based on the second IQ digital signal; The first SD memory card is used to store the first NMEA information and the second NMEA information.

15. The GNSS antenna performance test system according to claim 14, characterized in that: The GNSS receiving and processing device further includes: The second SD memory card is used to store the first IQ digital signal and the second IQ digital signal.

16. The GNSS antenna performance test system according to claim 15, characterized in that: The GNSS receiving and processing device further includes: An RTC circuit, configured to calibrate the GNSS baseband processing and analysis circuit using UTC time; A lithium battery circuit is used to supply power to the first GNSS radio frequency circuit, the second GNSS radio frequency circuit, and the GNSS baseband processing and analysis circuit.

17. The GNSS antenna performance test system according to claim 11, characterized in that: The GNSS receiving and processing device further includes: TCXO circuit, used for providing a reference clock to a clock synchronization circuit; The clock synchronization circuit is used to provide the reference clock to the first GNSS radio frequency circuit, the second GNSS radio frequency circuit, the GNSS baseband processing and analysis circuit, and the GNSS radio frequency signal acquisition circuit respectively.

18. The GNSS antenna performance test system according to claim 1, characterized in that: The GNSS receiving and processing device further includes: A metal shielding box, wherein the first GNSS radio frequency circuit, the second GNSS radio frequency circuit, and the GNSS baseband processing and analysis circuit are located in a shielding cavity of the metal shielding box.

19. A GNSS antenna performance testing method, characterized in that: Applicable to the GNSS antenna performance test system according to any one of claims 1 to 18, the GNSS antenna performance test method comprising: receiving a first GNSS satellite signal from a GNSS satellite; receiving a second GNSS satellite signal from the GNSS satellite; Acquire a first IQ digital signal according to the first GNSS satellite signal; Acquire a second IQ digital signal according to the second GNSS satellite signal; Acquire a first C / N0 sequence according to the first IQ digital signal, and acquire a second C / N0 sequence according to the second IQ digital signal; determining a gain and / or pattern performance of the GNSS antenna under test according to the first C / N0 sequence and the second C / N0 sequence; Determining the directional pattern performance of the GNSS antenna under test according to the first C / N0 sequence and the second C / N0 sequence includes: Acquire a first azimuth sequence and a first elevation sequence according to the first IQ digital signal, and acquire a first local star map of a standard GNSS antenna according to the first azimuth sequence, the first elevation sequence, and the first C / N0 sequence; acquiring a second azimuth sequence and a second elevation sequence according to the second IQ digital signal, and acquiring a second local star map of the GNSS antenna under test according to the second azimuth sequence, the second elevation sequence, and the second C / N0 sequence; The directional pattern performance of the measured GNSS antenna is determined according to the first local star map and the second local star map.

20. The GNSS antenna performance testing method according to claim 19, characterized in that: Determining the gain of the GNSS antenna under test according to the first C / N0 sequence and the second C / N0 sequence includes: Determining whether each C / N0 value in the second C / N0 sequence is greater than a first preset carrier-to-noise ratio threshold; If yes, the gain of the measured GNSS antenna is determined according to the C / N0 difference between the first C / N0 sequence and the second C / N0 sequence.

21. The GNSS antenna performance testing method according to claim 20, characterized in that: Obtaining the C / N0 difference includes: Generate a first C / N0 curve and a second C / N0 curve according to the first C / N0 sequence and the second C / N0 sequence respectively; The C / N0 difference is determined according to the first C / N0 curve and the second C / N0 curve.

22. The GNSS antenna performance testing method according to claim 19, wherein: The method further comprises: Determining a plurality of comparison satellites of the GNSS satellite, obtaining a C / N0 difference of each comparison satellite, and determining an arithmetic mean of the C / N0 differences of each comparison satellite as a total gain difference of the measured GNSS antenna; The gain of the GNSS antenna under test is determined according to the gain of the standard GNSS antenna and the total gain difference.

23. The GNSS antenna performance testing method according to claim 20, wherein: The obtaining of the C / N0 difference of each comparison satellite includes: Determine each first comparison C / N0 sequence according to each first comparison IQ digital signal, and determine each second comparison C / N0 sequence according to each second comparison IQ digital signal; Determine the C / N0 difference between each first comparison C / N0 sequence and each second comparison C / N0 sequence as the C / N0 difference of the corresponding comparison satellite; Among them, each first comparison IQ digital signal is obtained by the first GNSS radio frequency circuit according to each first comparison satellite signal, each second comparison IQ digital signal is obtained by the second GNSS radio frequency circuit according to each second comparison satellite signal, each first comparison satellite signal is received by the standard GNSS antenna from each comparison satellite, and each second comparison satellite signal is received by the measured GNSS antenna from each comparison satellite.

24. The GNSS antenna performance testing method according to claim 19, wherein: The method further comprises: Determining a test validity period according to the operating speed and orbital parameters of the GNSS satellite, and determining an azimuth angle change value and an elevation angle change value of the GNSS satellite within the test validity period according to the test validity period; Dividing the test scene space into a plurality of local space regions according to the azimuth angle change value and the elevation angle change value; Acquiring the first local star map includes: obtaining a C / N0 average value of the standard GNSS antenna in each local space region according to the first azimuth angle sequence, the first elevation angle sequence, and the first C / N0 sequence, marking the C / N0 average value of the standard GNSS antenna in each local space region on the corresponding local space region, to obtain the first local star map; Acquiring the second local star map includes: Obtain a C / N0 average value of the measured GNSS antenna in each local spatial area according to the second azimuth sequence, the second elevation sequence, and the second C / N0 sequence, mark the C / N0 average value of the measured GNSS antenna in each local spatial area in the corresponding local spatial area, and obtain the second local star map.

25. The GNSS antenna performance testing method according to claim 24, characterized in that: The dividing the test scene space into a plurality of local space regions according to the azimuth angle change value and the elevation angle change value includes: The horizon is defined as the 0-degree line, and the area directly above the standard GNSS antenna or the GNSS antenna under test is defined as the zenith. The angle between the 0-degree line and the standard GNSS antenna or the GNSS antenna under test is defined as the elevation angle range, and the angle of 360 degrees is defined as the azimuth angle range. The azimuth angle range is divided into N azimuth angle division areas according to the azimuth angle change value, and the elevation angle range corresponding to each azimuth angle division area is divided into M elevation angle division areas according to the elevation angle change value, thereby obtaining N×M local space areas.

26. The GNSS antenna performance testing method according to claim 24, wherein: The method further comprises: Drawing a color change mark in the corresponding local space area according to the C / N0 average value of the standard GNSS antenna in each local space area; Drawing a color-changing mark in the corresponding local spatial area according to the C / N0 average value of the GNSS antenna under test in each local spatial area; The color-changing mark changes in a preset color gradient sequence as the C / N0 average value of the standard GNSS antenna in each local spatial area or the C / N0 average value of the tested GNSS antenna in each local spatial area increases.

27. The GNSS antenna performance testing method according to claim 24, wherein: The obtaining, according to the first azimuth sequence, the first elevation sequence, and the first C / N0 sequence, a C / N0 average value of the standard GNSS antenna in each local spatial area includes: determining, based on the first azimuth angle sequence and the first elevation angle sequence, a first C / N0 subsequence of the first C / N0 sequence located in each local spatial area, determining at least one first target C / N0 value greater than a second preset carrier-to-noise ratio threshold in each first C / N0 subsequence, and calculating a C / N0 average value of the standard GNSS antenna in each local spatial area based on the at least one first target C / N0 value; The obtaining, according to the second azimuth angle, the second elevation angle, and the second C / N0 sequence, a C / N0 average value of the measured GNSS antenna in each local spatial area includes: Determine, based on the second azimuth sequence and the second elevation sequence, a second C / N0 subsequence of the second C / N0 sequence located in each local spatial area, determine at least one second target C / N0 value greater than the second preset carrier-to-noise ratio threshold in each second C / N0 subsequence, and calculate, based on the at least one second target C / N0 value, a C / N0 average value of the measured GNSS antenna in each local spatial area.

28. The GNSS antenna performance testing method according to claim 24, wherein: The method further comprises: Calculating a test period based on the operating period of the GNSS satellite and the test validity period; Obtaining a first panoramic starry sky image and a second panoramic starry sky image of the standard GNSS antenna and the GNSS antenna under test respectively during the test period; The directional pattern performance of the measured GNSS antenna is determined according to the first panoramic star map and the second panoramic star map.

29. The GNSS antenna performance testing method according to claim 19, wherein: The method further comprises: Acquire the first IQ digital signal according to the acquisition instruction, and acquire a third C / N0 sequence according to the first IQ digital signal; If there is a third target C / N0 value less than a third preset carrier-to-noise ratio threshold in the third C / N0 sequence, the first IQ digital signal is FFT transformed to generate a first spectrum diagram, and it is determined whether there is an interference signal in the GNSS frequency band based on the first spectrum diagram and the pre-acquired standard spectrum diagram.

30. The GNSS antenna performance testing method according to claim 29, wherein: The method further comprises: If the interference signal exists, it is determined that the gain and / or pattern performance of the GNSS antenna under test is invalid.

31. A GNSS antenna performance test device, characterized in that: For implementing the GNSS antenna performance testing method according to any one of claims 19 to 30, the device comprises: A first receiving module, configured to receive a first GNSS satellite signal from a GNSS satellite; A second receiving module, configured to receive a second GNSS satellite signal from the GNSS satellite; A first acquisition module, configured to acquire a first IQ digital signal according to the first GNSS satellite signal; A second acquisition module, configured to acquire a second IQ digital signal according to the second GNSS satellite signal; a third acquisition module, configured to acquire a first C / N0 sequence according to the first IQ digital signal, and acquire a second C / N0 sequence according to the second IQ digital signal; a determination module, configured to determine a gain and / or pattern performance of the GNSS antenna under test based on the first C / N0 sequence and the second C / N0 sequence; Determining the directional pattern performance of the GNSS antenna under test according to the first C / N0 sequence and the second C / N0 sequence includes: Acquire a first azimuth sequence and a first elevation sequence according to the first IQ digital signal, and acquire a first local star map of a standard GNSS antenna according to the first azimuth sequence, the first elevation sequence, and the first C / N0 sequence; acquiring a second azimuth sequence and a second elevation sequence according to the second IQ digital signal, and acquiring a second local star map of the GNSS antenna under test according to the second azimuth sequence, the second elevation sequence, and the second C / N0 sequence; The directional pattern performance of the measured GNSS antenna is determined according to the first local star map and the second local star map.

32. A computer-readable storage medium, characterized in that A computer program is stored therein, and when the computer program is run on a processor, the GNSS antenna performance testing method according to any one of claims 19 to 30 is executed.

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