SJ 20621-1997 Military weather radar tactical performance test method
Some standard content:
Military Standard of the Electronic Industry of the People's Republic of China FL5840
SJ20621—97
Test methods for tactical performance of military weather radars1997-06-17Published
1997-10-01Implemented
Ministry of Electronics Industry of the People's Republic of China
Military Standard of the Electronic Industry of the People's Republic of ChinaTest methods for tactical performance of military weather radarsScope
1.1 Subject Content
This standard specifies the test methods for tactical performance of military weather radars. SJ 20621-97
1.2 Applicable Model
This standard applies to the test of tactical performance of military weather radars and is the basic basis for the formulation of design and finalization test outlines. 2. Reference documents
GB 3784--83
GB/T12649—90
GJB 74.2—85
GJB150.1-86
SJ 3223—89
SJ20419—94
SI2062097
3 Definitions
Terms and terms
Meteorological radar parameter test methods
General technical conditions for military ground radars Common terms and terms General principles for environmental test methods for military equipment
General technical conditions for ground radar transmission systems Tactical performance test methods for ground guidance radars General specifications for military weather radars
Terms not specified in this standard shall be subject to GB3784, GJB4.2 and S20620. 3.1 Tested radar
Radar submitted for tactical performance test.
3.2 Tactical performance testtestfortacticalperformanceTests conducted to achieve the main combat and use functions. "Generally refers to range tests and troop trials.4 General requirements
4.1 Tested radar
4.1.1 The tested radar must meet the technical performance of the whole machine and system specified in the product specifications and pass the environmental adaptability test.4.1.2 Unless otherwise specified, all tests shall be carried out under the conditions specified in Article 3.1.1 of GIB150.1.4.1.3 Unless otherwise specified, the power supply voltage and frequency during the test shall be the power supply voltage and frequency specified in the product specifications of the tested radar.
4.2 Installation, inspection and adjustment of the tested radarPromulgated by the Ministry of Electronics Industry of the People's Republic of China on June 17, 1997 and implemented on October 1, 1997
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4.2.1 After the radar under test is in the designated position and is erected and debugged normally, the following parameters should be tested: a. Transmitter operating frequency; h. Receiver sensitivity (or noise coefficient); c. Transmitter output power; d. Antenna base level; e. Antenna inter-service control accuracy.
4.2.2 During the detection accuracy test, the radar shall be erected, adjusted and calibrated according to the product specifications. No other methods shall be used to correct the positioning system error of the radar under test. 4.3 Technical status of the radar under test during the test 4.3.1 During the test, the operation and maintenance of the radar shall be managed by a dedicated person (usually the maintenance support group) assigned by the test department to ensure that the radar is in normal working condition. Without the consent of the test department, the technical status of the radar shall not be changed or adjusted. 4.3.2 The contractor shall propose preventive maintenance rules. After approval, the maintenance support group shall perform preventive maintenance on the radar as required.
4.3.3 During the test, the technical status and fault conditions of the radar shall be registered in detail. 4.3.4 Weather radar beams are generally needle-shaped beams. The test target must be scanned during the test. It is very difficult. During the detection range and detection accuracy test, there should be other radars to guide. 4.3.5 The simulated point targets used in the test should generally be balloon-shaped metal targets or other aircraft. 4.4 Requirements for the test radar site and meteorological conditions 4.4.1 The test radar site should avoid large metal buildings, high-power radio stations, high-voltage lines, etc. as much as possible. For flight tests in the main test flight direction, the electromagnetic interference intensity should be less than the normal noise level of the radar. For erection and dismantling tests, the site should be large and wide to ensure normal erection and dismantling.
4.4.2 The shielding angle should be small in the main test flight direction. Angle of 1 beam width. 4.4.3 The radar site under test shall have lightning protection measures. 4.4.4 The detection accuracy test shall be carried out under clear sky weather conditions and the specified radar working environment conditions. It shall be ensured that the test flight route is simple weather, without precipitation, atmospheric waveguide phenomenon and abnormal propagation conditions. The terminal test shall be carried out in cloudy and rainy weather.
4.5 Test equipment
The accuracy of the test equipment that measures the main parameters of the radar under test and provides the true value of the target data during the control accuracy test shall be better than one-third of the allowable error of the measured index. The test equipment shall have a certificate of qualification and a certificate of validity. If it exceeds the validity period, it shall be used after calibration.
4.6 Test organization
4.6.1 Test department
The tactical performance test shall be carried out by a special test site or a user unit designated by the superior. The test organization of the test site shall be carried out in accordance with the relevant regulations of the test site.
4.6.2 Test and Appraisal Group
4.6.2.1 The test and appraisal group shall be composed of representatives of the user and the contractor, and the user representative shall be the group leader and the contractor shall be the deputy group leader.
4.6.2.2 The tasks of the test and appraisal group are: a. Submit the test implementation plan according to the test outline; b. Be responsible for the organization of the test
c. Submit an assessment report on the test results.
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4.6.2.3 The test and appraisal group consists of a technical data group and a maintenance support group: b. The technical data group is responsible for the specific implementation of the test plan, obtaining and processing the main tactical and technical data of the test radar, and submitting the test results and opinions to the test and appraisal group; b. The maintenance support group is responsible for the maintenance support of the test radar during the test, and provides the test and appraisal group with relevant technical performance data of the test radar.
4.6.3 Test leadership team
4.6.3.1 The test leadership team is composed of the leader and deputy leader of the test appraisal team and the person in charge of the test task of the unit. The person in charge of the test task of the unit shall be the leader. 4.6.3.2 The tasks of the test leadership team are: a. Formulate a test plan according to the test plan, such as: flight plan, various test arrangements, etc. b. Submit a test summary report after the test. 4.6.4 Requirements for test radar operators
The test radar operator should have proficient radar operation experience, understand the basic performance of the test radar, and master the operation method. 4.7 Test
After the preparation work is ready, the test shall be carried out according to the test outline. 4.8 Test interruption and test continuation
4.8.1 Test interruption
When any of the following situations occurs, the test plan shall be suspended, and the test leadership group shall write a report to the competent department and interrupt the test after approval:
a. On the date specified in the test plan, the test equipment cannot meet the specified requirements and cannot be repaired within the specified time; b. During the test, any technical indicator that has a significant impact on the main tactical performance of the test fails to meet the requirements and cannot be restored to normal within the specified time;
c. The main backup equipment is used up and cannot be started normally and cannot be provided within the specified time; d. Other unexpected events that affect the test conclusions occur. 4.8.2 Test continuation
When the cause of the test interruption has been eliminated, the test leadership group shall write a detailed analysis report to the competent department and the test can be continued after approval.
4.9 Test Records and Reports
4.9.1 Test Records
For flight tests, during the test, the technical data group must collect and record the original data related to the test in detail at the test site, including the following:
a. Test site data: latitude and longitude of the site (error less than 1), magnetic declination of the site, site elevation (error less than 10m), surrounding terrain map (marking various landmarks, islands, etc. that have an impact on the test radar test), and terrain profile map in the test flight direction;
b. Meteorological data:
c. Corner reflector size;
d. Test record of the technical status of the test radar;
e. Accuracy report of instruments and standard equipment;
f.Test data: automatic recording, printing records, etc.;—3
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Department. Test radar working records, fault and maintenance records; h. During the accuracy test, provide the target data true value standard equipment record. 4.9.2 Tactical performance test report
After the test, the test leadership team shall provide a test summary report, including the following contents: a. The basis, time, location, project and implementation process of the test: b. The technical status of the test radar;
c. The accuracy of instruments and standard equipment:
d. Test results and conclusions;
e. The main problems and improvement suggestions of the test radar. 5 Test method
5.1 Working frequency
5.1.1 Scope of application
This method is applicable to testing the working frequency of the test radar. 5.1.2 Requirements for test equipment and radar under test
a. The test equipment shall comply with the provisions of Article 4.5; b. The attenuation range of the sampling equipment (directional coupler) shall meet the working level requirements of the frequency test equipment; c. The radar under test shall comply with the provisions of the product specification after inspection. 5.1.3 Test procedure
According to the test system shown in Figure 1, measure the operating frequency of the transmitting system, that is, the operating frequency of the radar under test. Transmitting system
5.2 Detection range
5.2.1 Applicable range
Equipment for measuring the rated frequency
This method (indirect method) is applicable to testing the detection range of the radar under test. 5.2.2 Requirements for test equipment and radar under test
a. The test equipment shall comply with the provisions of Article 4.5; b. The radar under test shall comply with the provisions of the product specification after measurement. 5.2.3 Test procedure
5.2.3.1 Measure the pulse envelope width z of the radar under test in accordance with the provisions of Article 5.2.3 of SI3223. 5.2.3.2 Measure the pulse repetition frequency ft of the radar under test in accordance with the provisions of Article 5.16 of GB/T12649. 5.2.3.3 Measure the output pulse power Pt within the operating frequency band of the radar under test in accordance with the provisions of Article 5.2.6 of S3223. P.
Wherein, P—output pulse power, W;
P-output average power, W;
r---transmitted pulse envelope width, s;
f.—transmitted pulse repetition frequency, Hz.
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5.2.3.4Measure the sensitivity Ping of the radar receiver under test Input a 100uW calibration signal with a frequency equal to the transmitter operating frequency at the input end of the receiver high amplifier, and observe the output signal at the receiver output end with an oscilloscope. Adjust the attenuation of the calibration signal so that the signal-to-noise ratio of the receiver output signal is 1, read the attenuation value of the calibration signal at this time, and then convert it to obtain the minimum measurable power in watts, that is, the receiver sensitivity Pmino5.2.3.5Measure the antenna gain G of the radar under test in accordance with the provisions of Article 5.4.3 of GB/T12649. 5.2.3.6 Use frequency measuring equipment to measure the operating frequency of the test radar transmitter, and then convert it to obtain the operating wavelength. 5.2.3.7 Calculate the maximum detection range of the test radar: Rmux
Where: Rmex—maximum detection range, km; P,—output pulse power (far end), W; Gantenna gain, dB;
8—horizontal beam width of the antenna, (\)1Φ—vertical beam width of the antenna, (\); [P,G hx/K1z
1024^21n2Pmin
h—the spatial thickness of the Paida wave train h=c (is the pulse width, c is the speed of light), mi yuan—pi;
K--the attenuation factor of electromagnetic waves when propagating in space, when the wavelength is 3~10cm and the temperature is 0~20℃, it can be taken as K~0.930±0.004;
Z--reflectivity factor, mm2/m;
>—the operating wavelength of the transmitter, m
Pmn receiver sensitivity (far end), W. 5.2.4 Verification of detection range
The verification of detection range should be carried out during the trial use of the troops. 5.3 Detection accuracy
5.3.1 Applicable countries
This method is applicable to the test of the range error, azimuth error, elevation error, height error and speed error of the tested radar. 5.3.2 Requirements for test equipment and test radar
5.3.2.1 The target coordinates measured by the standard equipment shall be converted to the coordinate system with the test radar as the origin according to the formula for coordinate system conversion in Xie Lu A (Supplement).
5.3.2.2 The time difference between the test radar and the standard equipment in synchronously recording the measurement data shall be less than 0.01s. 5.3.2.3 Other requirements are the same as those in Article 5.2.2. 5.3.3 Test conditions
5.3.3.1 The number of tests shall not be less than 10.
5.3.3.2 Data collection: The batch number, azimuth, distance, altitude and time data of the test radar and standard equipment measuring the national standard can be processed in real time by the recording computer.
5.3.4 Test procedure
Test and collect data according to the number of tests specified in Article 5.3.3. TTKAONKAca-
5.3.5 Data processing
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5.3.5.1 In the order of the time when the tested radar measured the target coordinate data, the coordinate data measured by the tested radar and the standard equipment shall be converted to the same coordinate system according to the coordinate system of Appendix A (Supplement), and the first-order difference of each measurement shall be calculated. 5.3.5.2 Each test shall be divided into segments according to the specified distance sampling interval. The first-order difference data within the same sampling interval constitutes the observation sample. The observation data at the intersection of the distance sampling interval is counted only once and is used as the observation point within a closer distance. 5.3.5.3 Eliminate abnormal data in the observation sample: When there is a clear reason to explain some abnormal data in the observation sample, these abnormal data should be eliminated. For example, test conditions change, operator error, etc.; b. When there is no clear reason to explain some excessive or insufficient data in the observation sample or the number of observation points is greater than 25, the data greater than 3 times the standard deviation in the primary difference shall be eliminated. 5.3.5.4 Process the primary difference after eliminating abnormal data: a. Calculate the mean of the primary difference:
b. Calculate the standard deviation of the secondary difference
c. Calculate the root mean square value of the secondary difference:
NIs+AX
——mean of the secondary difference, m;
In formulas (3), (4), and (5): 4X
4X;——the i-th primary difference in the;th test voyage, mN the number of observation points within the sampling interval of the j-th test voyage; S the standard deviation of the primary difference, m
the root mean square value of the primary difference, m.
5.3.5.5 Synthesis of errors of each flight:
The statistical quantities of the first-order difference of all test flights at the same distance sampling interval are integrated according to the following method and sequence to obtain the detection error of the test radar.
. Calculate the root mean square error:
h. Calculate the systematic error:
c. Calculate the random error:
(Uz - AX4
In formulas (6), (7) and (8): U--root mean square error, mF--test flight;
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NTotal number of observation points in the same distance interval; ZXSystematic error, m
S-Random error, m.
5.3.5.6 When finally determining the root mean square error U of the actual measurement accuracy of the test radar, the measurement error of the standard equipment should also be deducted. U' - u?- u?.
Where: U——Root mean square error of actual measurement accuracy of the tested radar, mU——Root mean square error calculated by the tested radar, mU, Root mean square error of standard equipment, m.
......(9)
5.3.5.7 According to the actual number of observation points N in the distance sampling interval, the ratio of the systematic error and random error of the tested radar K is checked by the curve in Appendix B (Supplement), and the confidence interval of the root mean square error of the tested radar under the specified confidence level is given. 5.3.5.8 For radars with automatic or semi-automatic admission, the target barriers measured after elimination in each distance interval should also be given. The ratio of the number of times the marked data is collected to the number of times the data is measured, and the reasons for the number of missed measurements shall be explained. 5.4 Resolution
a. The distance resolution is determined by the width of the transmitted pulse envelope: b. The angle resolution is determined by the antenna beam width: c. The intensity resolution is guaranteed by the design:
d. The speed resolution is guaranteed by the design.
5.5 Quick response
The test method for quick response shall comply with the provisions of Method 106 in SI20419. 5.6 Maneuverability
5.6.1 Scope of application
This method is applicable to checking the maneuverability requirements of the radar under test. 5.6.2 Requirements for test equipment and radar under test
The radar under test should be complete and in the marching state. 5.6.3 Loading method
Check the loading method of each radar unit according to the requirements of the design documents. 5.6.4 Transportation method
The road transportation test is carried out in combination with the radar sports car test: the railway transportation test is to install the whole set of radar in the marching state on the train; the water transportation, air transportation and transportation tests are carried out according to the procedures specified in the contract. 5.6.5 Number of transportation units
The radar under test should be complete and in the marching state. Check the number of radar transportation units according to the requirements of the design documents. 5.6.6 Disassembly time
The test method for disassembly time shall be in accordance with the provisions of method 107 in S20419. 5.7 Radar terminal
5.7.1 Scope of application
This method is applicable to the inspection of the terminal of the radar under test. 5.7.2 Requirements for test equipment and test radar
a. The test equipment shall comply with the provisions of Article 4.5. b. After inspection, it shall comply with the provisions of the product specification. 7-
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5.7.3 Test conditions
All radar systems shall be able to work normally.
5.7.4 Inspection of signal processing subsystem
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Compare with the physical object inspection, there shall be a multi-function signal processor and automatic fault monitoring device. 5.7.5 Inspection of data processing subsystem
5.7.5.1 Compare with the physical object inspection, the computer host, display, printer, communication interface, etc. shall comply with the provisions of the product specification. 5.7.5.2 Inspection of three remote functions (telemetry, remote control, and remote transmission): Run the three remote function software to check whether the test radar has the three remote functions. 5.7.5.3 Inspection of target strength and velocity information processing: a. Real-time PPI (multi-elevation) display and acquisition of strength, velocity, and spectrum width; b. Real-time PHI (multi-azimuth) display and acquisition of strength, velocity, and spectrum width; c. CAPPI acquisition of intensity data.
5.7.5.4 Inspection of other application software:
Run the fault monitoring, calibration, communication wind field inversion and graphics processing programs respectively, which shall comply with the provisions of the product specifications. 5.8 Continuous working time
5.8.1 Scope of application
This method is applicable to the continuous working time of the test radar. 5.8.2 Requirements for test equipment and test radar a. The test equipment shall comply with the provisions of Article 4.5; b. The test radar shall be debugged normally and comply with the provisions of the product specifications. 5.8.3 Test procedure
5.8.3.1 Power on and operate according to the continuous working time specified in the product specifications, and use a timer to record the power on and off time. 5.8.3.2 When the test is turned on for 20 minutes, perform the "pre-test" test according to the Group A inspection items specified in the test radar product specification. After the test, turn on the whole machine and start timing. 5.8.3.3 During operation, perform the "operation" test (test items are specified in the product specification) at a certain time interval (the time is specified in the product specification), and cut off the power (not included in the test time) to perform necessary maintenance on the radar. During the test, it is allowed to fine-tune the extension with an external adjustment device.
5.9 Power supply mode and power consumption of the whole machine
5.9.1 Scope of application
This method is applicable to testing the power supply mode and power consumption of the whole machine of the test radar. 5.9.2 Requirements for test equipment and test radar
a. The test equipment shall comply with Article 4.5 provisions; b. The radar under test should be set up and the alarm should be normal and meet the requirements of the product specifications. 5.9.3 Test procedure
5.9.3.1 Connect the power station to provide the radar with a three-phase 50Hz, 380V power supply and check the working conditions of each system. 5.9.3.2 Connect all electrical equipment (including auxiliary equipment) of the radar under test, read the voltage and current values on the distribution device, and calculate the total power consumption according to formula (1):
P=UIcos±x10-3...
Where: P-total power consumption, kW,
U-- voltage value, V;
I--current value, A;
cos-m-power factor.
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Appendix A
Coordinate system conversion
(Supplement)
A1 Establish a polar coordinate system O(o, D,,) with the center of the earth as the origin, as shown in Figure A1:7.
Coordinate origin, center of the earth:
D-distance to the origin, km;
Longitude, (\):
M-latitude, (\):
A(Di,1, Hong)--—Geographical coordinates of station A; B(D2,72,)—Geographical coordinates of station B;
M——target.
A2 With stations A and Station B is the origin, and polar coordinate systems are established respectively. The coordinates of target M in the polar coordinate system of station A are MR, 1-β,); the coordinates of M in the polar coordinate system of station B are M(R2, α2β2]. Among them: R--slant distance, the distance between the ear mark M and the coordinate origin; azimuth, the angle between the line connecting the projection of target M on the horizontal plane and the coordinate origin and the true north, (\); β--elevation angle, the angle between the line connecting target M and the origin and the horizontal plane, (\). A3 Take stations A and B as the origin, and establish rectangular coordinate systems respectively. The coordinates of target M in the rectangular coordinate system of station A are 9
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M(X1,Yi.Z,);M's coordinates in the rectangular coordinate system of station B are M(X2,Y2,Z2). Where: Z axis - the axis passing through the origin of coordinates and the center of the earth, the direction away from the center of the earth is positive; Y axis - passing through the origin of coordinates, pointing to the geographic north; X axis - the relationship with the Y axis and Z axis conforms to the provisions of the Cartesian coordinate system. A4 Conversion of rectangular coordinates between stations A and B; [X2 = PiXi + P2Xi + P3Zi - P10*Y+- PaX + P,X, +P,z,+ Ph*.
Z- - PXi+ P: Y1+ PZ1+ P12*
Where: P, - cos( );
Pz = — sintisin(i Y2);
P,=cosisin(12);
Pa= sinpisin (1-72); ||tt | cosicos2cos(71 -Y2);P10 = picosyisin(71- 72);
Pu = - P,[singcos cosisindzcos(Y -2)]; Pr2 = pysinpi[sinp2 + cosdicos2cos(1 - 72)]. A5 Coordinate conversion
A5.1 The rectangular coordinate system with the same origin is converted into polar coordinates according to formulas (A4), (A5), (A6): Y
R=/x+y+z.\
A5.2 The polar coordinate system with the same origin is converted into rectangular coordinates according to formulas (A7), (A8), (A9): X - Rsinα cosp...
Y Rcosasing.
Z=Rsing+
A6 The standard equipment A and the test radar B are set at any two points on the earth. The coordinate conversion method is as follows: (A1)
（A4)
The coordinates of the target M actually measured by station A are the polar coordinates M(R1,αl,βi) with station A as the origin. Therefore, firstly, apply formula (A7)-(A9) to convert M(RI,α1.P) into rectangular coordinates M(X1,Y1,Z}), then apply formula (A1~A3) to convert it into the rectangular coordinates M(XzY2,Z2) of the rectangular coordinate system of station B, and finally use formula to convert it into the polar coordinates Mto
(R2, az. β2) at station B. bzxZ.net
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A7 Under the condition that the standard equipment A is set near the test radar B, stations A and B can be arranged as two parallel coordinate systems in the same plane without the influence of the earth's curvature (the height difference between the two stations is still considered. In this case, the coordinate conversion is carried out in the following order:
The polar coordinates M(R41,β) of the target M measured by station A are converted into rectangular coordinates M(X1.Y1,Z1), measure the rectangular coordinates of point B in the station coordinate system B (Xa.Ya.Zr). Therefore, the rectangular coordinates of the target in the rectangular coordinate system are M (X2, Y2, Z2). Among them, X, = Xi- X....
Y = Y - Y
Z2 = 2 - Z...
Finally, apply formulas (A4)~(A6) to convert M(Xz,Y2, Z) into M(R2,a2,β2). (A10)
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