RADAR Engineering- YLC-6M Radar System IlI

       Battle Operation of YLC-6M Radar System

The battle operation of YLC-6M radar refers to activities that operators adjust radar’s operation modes, cancellation area, display setting, signal processing setting, communication setting, and etc. according to various conditions such as target, display, landmark, weather and jamming.

YLC-6M radar generally operates in normal operation state. It operates in anti-weather operation state when there is weather interference. It uses different anti-jamming operation modes if there is hostile active jamming. Now, we describe the battle operation of YLC-6M radar respectively.

Normal Operation

 Operation modes

The normal operation of YCL-6M radar refers to operation in the condition of weak weather echo and without electromagnetic jamming. In this case, there is only fixed ground clutter, so the radar adopts MTD operation mode, i.e., normal non-weather operation mode.

 Operation range and antenna rotation rate

When YLC-6M radar is being used for air surveillance, its operation range can be adjusted to 200km, 150km and 120km according to different air surveillance volumes and data rates. For general air surveillance task, 200km and 150km range can be selected. Its corresponding antenna rotation rate is 6rpm. If 12rpm is used in the two ranges, the number of echoes in a single beam of the radar system will be decreased by a factor of 2. It will greatly increase the processing loss of the radar system so as to have a certain effect on the radar coverage range. Thus, it is not suggested that 12rpm is used in the operation range of 150km and 200km. 120km operation range corresponds to 12rpm antenna rotation rate. In this operation mode, radar’s data rate will be increased by a factor of 2. It is mainly used for the search and surveillance of low altitude fast targets so as to rapidly form tracks and provide the command and control system with more target information.

 Selection of MTD filter bank

In MTD operation mode, filter bank I, filter bank II and filter bank III on the master monitoring console respectively represent four different filter banks as follows:

          Filter bank I (clutter area):

                   Filter zero depth£-60dB (±14Hz bandwidth)

Sidelobe level£-30dB

Zero frequency filters are shut off.

Filter bank II (clutter area)

Filter zero depth £-60dB (±12Hz bandwidth)

Sidelobe level £-30dB

Zero frequency filters are shut off.

Filter bank III (clutter area)

Filter zero depth £-60dB (±30Hz bandwidth)

Sidelobe level £-13dB

Zero frequency filters are shut off.

Filter 0 (non-clutter area)

8 best matching filters (covering the whole range of all the filters, filter I, filter II and filter III)

Filter bank I and filter bank II have similar functions. They are used in the case that there is ground clutter around the radar and the clutter spectrum is narrow. If there is light weather clutter, filter bank III can be selected. This filter bank has better spectrum rejection performance in frequency domain (30Hz).

The specific operation method is to respectively push down the three buttons for filter bank I, II and III on the master monitoring console, which are interlocked one another. In this case, the corresponding MTD filter bank (i.e., filter bank I, or filter bank II or filter bank III) operates. Filter 0 operates when all the three buttons are bounced up.

 Selection of dynamic/static clutter map

In the signal processor subsystem, there are 8 kinds of preset static dynamic clutter maps (static STC control). 0# means there is no STC control (i.e., full 0 for STC). STC control amount (theory value) increases successively from 1#~7# clutter map.

When the radar arrives at some site, power it on to observe the landmark around the radar. If the landmark occupies a smaller area and has a weaker strength, the static clutter map with smaller STC control amount will be selected (such as 1# and 2#). Otherwise, the static clutter map with larger STC control amount (such as 6# and 7#) will be selected. If the landmark range is large and beyond the control range of the static clutter control map (for example, there is stronger ground clutter at a range of 80km.) and the strength of the landmark is strong, both a proper static clutter map and a dynamic clutter map will be used in order to reject ground clutter better.

 Selection of dynamic/static clutter contour map

Clutter contour map is a map to control the cancellation of ground clutter, i.e., to control whether filter 0 in the filter bank of the signal processor subsystem is switched on or not. There are 4 kinds of static clutter contour maps in the radar signal processor subsystem. 0# clutter contour map refers to non-cancellation in full range (i.e., when cancellation is carried out in all the coverage, 0# filter is switched off.). 1# to 3# clutter contour maps respectively correspond to the cancellation within the range out to 50km, 100km and full range.

When the radar arrives at some site, turn it on to observe the landmark around the site. Different static clutter contour maps are selected based on the range of the landmark away from the radar site. For example, when the ground echo is in a range of 87km away from the radar or the main radar observation direction, the static clutter contour map within 100km should be selected. In order to make a further rejection on the ground clutter, dynamic clutter contour map might be selected, which can automatically establish clutter contour map in two dimensions (azimuth and range) based on the static clutter contour map and make cancellation processing within it.

PPI picture without cancellation on some radar site

PPI picture after a clutter contour map is selected

PPI picture after a dynamic clutter contour map is selected
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RADAR Engineering- YLC-6M Radar System II

schematic drawing of YLC-6M radar’s location

YLC-6M Radar System II

Main Features of YLC-6M Radar System

YLC-6M radar has the following five outstanding features:

(1) High mobility

YLC-6M radar adopts many advanced techniques such as accurate automatic hydraulic leveling, hydraulic folding and deploying of the antenna edge blocks, automatic north alignment and location, and etc.

The whole radar system is installed on a 6-meter-long carrier vehicle platform. Its setting-up and disassembling are conducted automatically.The operation is simple and rapid.

 For the whole radar system, the setting-up time is 8 minutes/4 men and the disassembling time is 6 minutes/4 men.

(2) Fully solid state transmitter

In YLC-6M radar system, a fully solid state centralized transmitter is used so as to achieve low peak power, high reliability, good maintainability, long life cycle and high full-life-cycle efficiency-cost ratio.

 The radar system can be powered up or shut down rapidly. It also can continue to operate for a long time to assume operational tasks.

(3) Good ECCM capability

l       Digital Moving Target Detection (MTD) processing technique is adopted to make the radar system have good anti-ground clutter and anti-chaff capability.

l       A full-coherent, fully solid state system is used to make the radar system have a very high frequency stability, a rapid adaptive pulse burst to pulse burst frequency agility, pulse to pulse frequency agility and pseudo-random pulse burst to pulse burst frequency agility, thus the anti-clutter capability of the radar system is assured. Pseudo-random frequency agility can be achieved compatible with MTI.

l       Digital pulse compression technique is used. A frequency modulation (FM) signal with a large product of time width and bandwidth is used to increase resolution and decrease meteorological interference. It is also helpful to anti-active jamming.

l       Low side-lobe antenna, wide band and circular polarization techniques are used, which are helpful to both anti-active jamming and anti-passive jamming.

(4) High reliability

In the radar system, a fully solid state transmitter and a two-channel, redundant thermal switching receiver are used to largely increase their reliability.

The use of miniaturization and integration techniques greatly reduces the quantities of components and plug-in boards, so a further increase of system reliability is achieved.

(5) High automatization

The radar system has BIT, extraction and tracking functions, provides an information network data communication interface, and can report data to the higher level command and control posts via wire/radio communication equipment.

 Composition of YLC-6M Radar System

YLC-6M radar equipment vehicle is mainly composed of sidelobe reflector antenna, transmitter, servo, hydraulic leveling, electronic cabin and platform. Inside of the electronic cabin, there are 3 electronic equipment cabinets (i.e., receiving and signal processor cabinet, display and data processor cabinet, and servo control cabinet), in which receiver, signal processor, radar terminal, timing and master control, target extraction, anti-jamming, servo hydraulic leveling control and other electronic equipment are installed. In addition, there are documentation cabinets and spare parts cabinets in it.

In order to decrease the setting-up time, disassembling time and number of operators, radar antenna, transmitter and other electronic equipments are all installed on one carrier vehicle platform.

Diesel generator power station is installed on a trailer, which can be towed by the radar vehicle. So there is only one transportation unit for the whole radar system.

YLC-6M radar equipment consists of carrier vehicle, operation cabin, antenna and pedestal, hydraulic platform and transmitter. The hydraulic platform is a platform to support the whole radar system. It provides a space for operators to operate the whole radar system. The carrier vehicle is a carrier with which the radar is transported. The transmitter is installed on the rear of the hydraulic platform, where there are also air cooling cabin and power cabin. Inside of the former, there are two high power centrifugal blowers. Inside of the latter, there are power amplification modules of each level for the transmitter, power supply modules, BITE and other electronic equipment. Antenna and its pedestal are in the middle of the whole hydraulic platform. In the small cabin below the pedestal, there are hydraulic subsystem’s driving circuit and control circuit, feedline, receiver’s RF equipment, and etc. Inside of the pedestal, there are feedline’s rotary joints, sliding ring and etc. The antenna includes its reflector, feed horn and etc. The antenna’s reflector is composed of three blocks. In transportation state, the two edge blocks can be lowered respectively to the two sides of the transmitter. In the operation cabin, there are servo control cabinet, display and data processor cabinet, receiver and signal processor cabinet, documentation cabinets and spare parts cabinets.

In the operation cabin, there are three cabinets. They are respectively servo control cabinet, terminal cabinet, as well as receiver and signal processor cabinet. The names and locations of units in each cabinet are shown in :

Servo control cabinet	Display and data processor cabinet	Receiver and signal processor cabinet
Power distribution unit	A/R display unit	Signal processor unit
Leveling control, north alignment unit	Raster display unit	Control unit
		Receiver unit
Servo control unit	Master console	Local oscillator
	Operator panel
Power supply unit	Terminal processing unit	Power supply unit I
Stand-by power supply unit		Power supply unit II
Blower	Communication switching unit	Switching unit
Switching unit

Setting-up Operation of YLC-6M Radar System

Requirements for Radar Site:

YLC-6M radar is highly mobile radar. All the radar equipments (excluding diesel generator power station) are installed on a 6m-long carrier vehicle platform. Therefore, it has lower requirements for its site and environment around the site. The specific requirements are as follows:

                          (1)Environments around the site

In the main observation direction, the blanking angle should be less than 0.2° and the ground surface should be flat. In order to decrease the interference as much as possible, the radar site should be away from broadcasting & TV station, large factory, transforming plant, high voltage line and etc. Around it, there shouldn’t be facilities that absorb electromagnetic wave such as high-speed railway, high bridge, mass of resident buildings, and etc.

                          (2) Radar setting-up site

In order to get better low altitude detection performance, a terrain with higher elevation should be selected as the radar setting-up site. The ground for the setting-up and adjustment of radar antenna should be a flat and solid area measuring 5´10(m²). On a temporary site, there is no need for staking; On a permanent site, one stake for grounding is needed.

                         (3) Lightning arrester

If the radar site is permanently used, a lightning rod should be installed. It shouldn’t be located in no main observation area. It should be 7~8m away from the antenna center. The grounding resistance shouldn’t be more than 3W. If the radar site is temporarily used, whether a mobile lightning rod is used will be decided by the weather condition in which the radar operates.

                         (4) Schematic drawing of radar site location

This represented the infrastructure of the being to the RADAR operation.

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RADAR Engineering- YLC-6M Radar System I

YLC-6M Radar System I

In the future war, rapid forces transferring and highly mobile operation will be a common-used tactical means.

 Low altitude and ultra low altitude attack now have become a common-used tactical means for air forces to avoid being detected. Additionally, in the future battlefield, there will be a variety of geographic and electromagnetic environments, many kinds of enemy electronic countermeasures.

All of these demand for a high performance radar that has the following performances: it can be disassembled, transported and set up rapidly; it has excellent electric performances, especially for detecting low altitude and ultra-low altitude targets; it has good ECCM performance and high reliability, and can be transported by land, sea and air; it can be powered on/powered off rapidly.

YLC-6M radar is a highly mobile, fully solid state, medium/low altitude surveillance radar developed in 1990s’ based on the operation demands by radar forces.

YLC-6M radar is a vehicle-carried, highly mobile, fully solid state, 2D, medium/low altitude surveillance radar in S band. It used fully solid state, full coherent, pulse compression and MTI detection techniques.

 The radar is characterized by good performances such as high mobility, high reliability, high Automatization and etc.

The radar is mainly used for highly mobile air surveillance, and detection of low altitude/ultra low altitude flying targets. It is also used to provide the operation and command system as well as aviation force with numerous synthetic information such as azimuth, range, foe/friend attribution of air targets. The acquired information can be introduced into the radar chain in real time. So it can be used as a highly mobile, medium/low altitude gap radar in the air intelligence radar chain. It can also be used as a stand-by radar to replace the destroyed radar. Its supplementary tactical function is to provide the air traffic control system in the airport with primary radar information of approaching control.

The radar has high maneuverability and strong ECM capability as well as higher survivability. Its main operation missions are:

a.     Suitable for rapid transfer in the battlefield and emergency mobile operation, to provide theater air situation surveillance so as to assure the operations and guidance of aviation forces;

b.     To detect low/ultra low altitude hostile targets and to prevent low/ultra low altitude sudden attacks;

c.      To rapidly enhance the deployment of the original radar chain and rapidly supplement the original radar chain so as to increase the local air situation provision capability.

d.     To play an unexpected role in the beginning of the war due to its mobile deployment capability and parameter shielding capability.

YLC-6M radar is mainly used to detect air targets such as kinds of fighters, attackers, bombers, EW aircraft, reconnaissance planes, transportation aircraft and civil flight planes. It has good detection capability for 

medium/low altitude targets, especially for low/ultra low altitude targets.

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