With the continuous progress of scientific development, the application of radar is more and more extensive. Radar can predict the future position of the target according to the trajectory of the moving target in national defense. Radar is not only used in national defense, but also can be used to measure the speed of linear moving objects, which is called radar velocimeter. Radar velocimeter can measure the real-time speed of moving objects according to the principle of Doppler frequency shift, and it is widely used in intelligent transportation. In addition to the functions of target location and speed measurement, through-wall radar can also be used for fire safety and can detect whether there is life at the fire site. This chapter mainly talks about the structural design principles of applying radar in ground defense.
The radar structure includes antenna feed, transmitting, receiving, servo tracking, signal processing, terminal, monitoring, power supply and distribution, software and other systems. According to the principle of system design, the function of a system depends not only on the constituent elements of the system, but also on the composition of these elements to a greater extent. Even if the components are unchanged, it is often only through system integration that a qualitative leap in the overall function can be achieved. Specifically, the radar structure design is not only the basic basis of technological processing, but also an important guarantee for the performance index and quality level of the whole machine.
Radar structural design requirements
1. Radar performance index requirements
(1). Radar operating frequency range
(2) Radar range and wave velocity of working mode
(3) detection or tracking performance (including size, detection or tracking accuracy, tracking speed, acceleration, resolution, etc. )
④ Ability to resist active interference and passive interference.
⑤ Anti-reconnaissance ability (confusion, concealment, etc.). )
6. Anti-destruction ability (including anti-ARM, anti-electromagnetic pulse weapon attack, etc.). )
⑦. Quick response ability (including startup time and working mode switching time, etc.). )
⑧. Mobility (including loading mode, compatibility with various modes of transport, number of transport units, driving and off-road capacity, participants and loading and unloading speed, etc.). )
⑨。 Reliability and maintainability (including MTBF, MTTR, etc. )
Attending doctor. Equipment composition (including theme equipment and supporting equipment, etc.). ),
2. Standardization requirements
① Implement national standards, national military standards and industrial standards, and actively adopt international standards and advanced foreign standards.
(2) Implement the Regulation on Standardization of Weapons, incorporate standardization into the whole process of radar product development, and carry out corresponding standardization work at various stages such as project demonstration, scheme, engineering development and finalization.
③ Make full use of existing scientific and technological achievements and "three-oriented" (generalization, serialization and modularization) resources, and actively carry out the demonstration design of radar "three-oriented". For example, in structural design, we should put "three-oriented", especially modular work, in a prominent position; Give priority to the use of universal and serialized products and universal modules; Give priority to standard poles, universal parts and universal structural parts, and minimize the varieties and specifications of parts, raw materials and their products; Choosing a suitable model is convenient for the formation of product information.
3. Use environment requirements
Generally speaking, the use environment of ground radar and its supporting equipment is as follows.
1). Outdoor environment
①. Working temperature: -45~55℃
②. Storage temperature: -55~70℃
④ Damp heat: relative humidity (95 3%) (30℃)
⑤. Low pressure: 70KPa, 0.5KPa (corresponding to altitude of 3000m and 5500m respectively). When the altitude of the radar position exceeds 3000 meters, the power supply, high-power transmission equipment, connectors and power cables must be treated accordingly before delivery.
2). Urban environment
① Working temperature: 0~40℃ or -20~45℃
② Damp heat: relative humidity (95 3%) (30℃)
③. Fresh air supplement: ≥ 15m3/ (person/hour)
④ Lighting: Daily lighting is 200Lx, and duty is 2~2-Lx, with adjustable illumination and door switch linkage.
⑥. Leakage energy: ≤25μW/ cm2.
3). Noise
(1) the noise between electronic equipment on duty should be less than 65dB(A), and that between electronic equipment on duty should be less than 75dB(A).
(2) The noise of the oil engine room should be less than 85dB(A).
(3) The measuring points in the city should be selected in the normal operation position or corridor of personnel, and the height from the ground is1.3 ~1.5m. ..
4). Vibration and shock
Take necessary vibration reduction and buffering measures, and conduct tests according to the relevant provisions of GJB 150. 16-86, GJB 150. 18-86 "Environmental Test Methods for Military Equipment" to ensure that all equipment is transported by land (road, cross-country and railway) and sea.
5). Lightning protection method
The lightning protection design of radar equipment and radar stations should be carried out in accordance with GB50057-94 Code for Lightning Protection Design of Buildings and other relevant standards, and measures such as interception, voltage equalization (equipotential), shunt, shielding and grounding should be taken to prevent the interference of direct lightning and induced lightning and ensure the safety of the whole radar and operators. Select advanced lightning arrester to convert the strong current impact of lightning on the ground into weak current discharge, and pay attention to the selection, arrangement, installation and grounding of lightning rod. Power cables, signal cables and their connectors should also be properly protected.
4. Structural design requirements
1). Appearance requirements
The appearance quality of ground radar products shall conform to the provisions of Article 3.3 of GJB74A-98.
2). Size and quality requirements
The dimensions, mass and center of mass of each installation unit and transportation single cloud of ground radar shall conform to the product specification and transportation clearance.
3). Interface requirements
(1). The mechanical connection mode and the stress requirement of the joint structure are simple, reasonable, convenient and reliable. In general, especially outdoor equipment, it is not allowed to use adhesive to bond; Flange form is preferred.
(2) Important or particularly complicated and harsh structures can only be used after calculation, analysis and test verification.
③ For the detachable parts of mobile radar, the mature, reliable, convenient and effective advanced connection methods such as quick connection, pre-tightening connection and fastening system should be given priority.
4). Material selection requirements
(1). Materials and their products shall meet the requirements of performance, price, size, quality, use conditions, installation interface, etc. , and meet the requirements of technical standards and the contractor's optimization manual.
2. Give priority to domestic products and actively and steadily use new materials.
(3) Generally, non-metallic flame retardant materials, metal materials with good mechanical properties, corrosion resistance, wear resistance and process performance are selected. When metal materials are mixed, they must be compatible with each other to prevent electrochemical corrosion caused by direct contact.
5). Mobility requirements
It has become an important task to improve the maneuverability of modern ground radar structure design, and transportation design bears the brunt and faces great challenges. How to complete the mutual conversion of radar working state (transportation state) with the least number of personnel and the shortest time while avoiding the overload of cross-country transportation has aroused great concern.
6). Reliability and maintainability requirements
The failure of mechanical parts and mechanical systems will not only induce the failure of electronic components, but also reduce the reliability of the whole radar. Therefore, the reliability and maintainability demonstration and design work must be carried out in accordance with the provisions of the contract, and the reliability and maintainability design criteria must be formulated and implemented.
7). Environmental adaptability
Technical measures such as optimizing structure, material selection, surface treatment and sealing drying are adopted to delay the corrosion and aging process to the maximum extent, prolong the service life of equipment and greatly enhance the environmental adaptability of radar products.
8). Electromagnetic adaptability
Electromagnetic compatibility is to enhance the adaptability of electronic equipment or system to electromagnetic environment through the application of shielding, grounding, filtering and other technologies, which can not only resist external interference, but also not cause excessive electromagnetic interference to other electronic equipment.