UPGRADING OF S-125M (PECHORA) ANTI-AIRCRAFT MISSILE SYSTEM

INTRODUCTION
  Classic modifi cation of any automated control system (ACS) provides capability to:
  • collect and transmit the information;
  • process and display the information;
  • analyze and output the control actions;
  • transmit the actions.
  The subsystem of collection and transmission of the information intended for control system of Air Force (AF CS) includes:
  • radar means of information collection;
  • radio means of information collection;
  • means of visual information;
  • means for reception and transmission of telecode information.
  Other ACS subsystems remain in the classical modifi - cations, except for the subsystem of transmitting control actions. The mentioned subsystems include:
  • means for reception and transmission of telecode information;
  • means for reception and transmission of voice information.
  Radar stations (RS) for airborne target detection belongs to the radar means of information collection of AF CS. Depending on the frequency of radiated sweeping signal, RS are divided into:
  • RS of VHF-band (P-18);
  • RS of UHF-band (P-15, P-19);
  • RS of S-band (36D6, PRV-11).
  The rest of the elements belongs to the subsystem of collection and transmission of information and includes equipment for visual surveillance and radio-stations of reception and transmission of telecode information.
  Maintenance of AF CS high effi ciency directly depends on the quality of subsystem’s operation for information reception and transmission, where its basic elements are RS which detect airborne targets. Due to the upgrade of the mentioned RS, a number of the important problems may be solved. These issues are connected both with the improving RS performance characteristics and with the support of reliability, controllability and reparability of their equipment.
  Upgrading of anti-aircraft missile systems (AAMS) provides signifi cant increasing of their operating characteristics, as well as:
  • enhancement of the combat performance capabilities of AAMS, including the expansion of realized lethal envelopes of air targets under the conditions of intensive jamming support;
  • decrease of AAMS response time in case of detecting and destroying air targets;
  • support of information-and-control interaction with adjacent AAMS and with the higher commanding point (HCP);
  • survivability rising of AAMS facilities under the conditions of high-precision weapon (HPW) use;
  • expansion of AAMS mobile properties.
  Besides the AAMS upgrade, can support introduction of modes on simultaneous tracking of several air targets and on their simultaneous engagement.
  AAMS upgrading version solves the problem of cost effi ciency, providing demanded quality with minimal costs.
  All works intended for the S-125M AAMS upgrade are connected with repair of the missile guidance radar (MGRS). Enhancement of the combat performance capabilities of SNR-125 will provide following results:
  • increase in detection and air-target range tracking;
  • increase in distant limits of target lethal envelopes, due to improvement of methods used for detection and measurement of targets coordinates and of anti-aircraft guided missiles (AAGM) under the conditions of clutters;
  • increase in effi ciency of AAGM jammers fi ring of generated clutters, owing to the implementation of coordinate support modes, special trajectory of fi red AAGM missiles and special algorithms of target selection against the background of non-stationary clutters;
  • improvement of the clutter protection, emission security and, consequently, survivability of the AAMS.
  In addition to this, reducing AAMS’s response time, in case of detection and destruction of air targets, following results will be achieved:
  • decrease of operational time of the AAMS, owing to the automation of processes connected with detection and target locking for tracking the aid of SNR-125, including the performance of these operational chains under the conditions of jamming;
  • decrease of the number of errors when target tracking is potential not only in the search mode, owing to upgrading of anti-feeding channel.
  Conducting repair and modernization works on information- and-control subsystems will result in achieving:
  • supporting of the information-and-control interaction of the AAMS with neighboring radio-engineering subunits;
  • supporting of the mutual interaction of the AAMS with neighboring air bases, specifi cally in cases of distributing efforts while destroying air targets.
UPGRADING OF UNV CABIN
  On the basis of the UNV cabin equipment the following devices are upgraded:
  • high-frequency element of receiving devices (UV-40M);
  • transmitting device of target-sighting channel (UV-20M);
  • television-optical sight (9W33);
  • electromechanical drive for rotation of upper side of radar head (head of assemblies equipped with current collector) according to azimuth (UV-2105); electromechanical drive for movement of head of assemblies, according to angle of elevation (UV-210E).
  Upgrading of high-frequency part of receiving devices
  On the basis of its assignment, the mentioned high-frequency part of receiving device will support:
  • reception of signals refl ected from targets;
  • reception of signals of missile transponders;
  • frequency selection, amplifi cation and conversing of received radio-frequency pulses;
  • gating and adjusting for amplifi cation of received signals.
  According to the receiving-device upgrade (the UV-40M cabinet) the following renovations will be completed:
  • Replacement of UHF-assemblies (the UV-420M and UV-42R assemblies) with upgraded semiconductor lownoise amplifi ers (LNA) of reduced noise factor;
  • Replacement of mixers assemblies (including preamplifi ers of intermediate frequency - UV-51-I and UV-51-II assemblies) with upgraded semiconductor assemblies;
  • Replacement of the detection assembly and preliminary amplifi cation of video-signals of missile transponders (the UV- 52M assembly) with the upgraded semiconductor assembly;
  • Replacement of assemblies of quick automatic fi ne tuning control of target (UV-47 and UV-48 assemblies) with upgraded semiconductor assembly;
  • Replacement of assemblies of the UV-141 power-supply and the UV-142 power-supply stabilizer with upgraded assemblies of solid-state technology.
  Use of the upgraded receiving device SNR-125 allows to extend parameters of the AAMS lethal envelope by 11%. Comparative characteristics of S-125 AAMS lethal envelopes in vertical plane are presented in Fig. 1.
  Comparative characteristics of S-125 AAMS lethal envelopes in horizontal plane are represented in Fig.2.
  Lethal envelopes are created for targets that fl y with speed of V4 < 300 m/second.

UPGRADE OF TRANSMITTING TARGET SIGHT CHANNEL DEVICE
  Upgrading program of transmitting device of target sight channel could be conducted with two options:
  • with replacement of the magnetron generator with multiple- beam klystron;
  • without the replacement of the magnetron generator;
  On the basis of general demands, with the respect to MGS, this transmitting device provides a number of characteristics given in the Table below.

COMPARATIVE CHARACTERISTICS OF TRANSMITTING DEVICE
number of fixed frequencies250 at least
frequency separation 
between adjacent fixed
frequencies
5 MHz10 M Hz
average output power60 kW4 kW
pulse relative duration
(at average
2020
output pulse power170 kW80 kW
minimal pulse duration0.26 ps0.4 ps
maximal pulse duration-160 ps
maximal pulse repetition
frequency
100 kHz100 kHz
high voltage25 kW25 kW
efficiency coefficient of 
transmitter
>15 %>20 %

UPGRADING OF DEVICE FOR TRANSMISSION OF MISSILE COMMANDS
  The presented upgrading of the receiving-transmitting device SNR-125 (second option) allows to extend parameters of the AAMS lethal envelopes by 28%. Comparative characteristics of lethal envelopes of the S-125 AAMS in vertical plane are represented in Fig.3
  Comparative characteristics of lethal envelopes of the S-125 AAMS in horizontal plane are represented in Fig.4. Lethal zones are created for targets which fl y with the speed V4 - 300 m/second.
  Reverting to the upgrading of missile-sighting of radiotransmitter and radio-transmitter of control commands, following adjustments have been made:
  • replacement of all the vacuum lamp assemblies with the upgraded solid-state or semiconductor assemblies;
  • replacement of the assemblies of high-voltage rectifi ers (UK-124 and UK-121 assemblies) and power-supply assembly (UK-122 assembly) with the upgraded assemblies of solid-state technology.
  New assemblies of solid-state technology enhance reliability and reduce weight-dimensional characteristics.

UPGRADING OF DEVICE FOR TRANSMISSION OF MISSILE COMMANDS
  The UK-20M and UK-20H upgraded cabinets have been demounted out of the UNK cabin and, lately, mounted in the UNV antenna head together with UV-12 antenna equivalents (UK-14 assembly and UK-15 assembly) and summation device (the UK-12 assembly).
NAME OF CHARACTERISTICSEXISTING 
RRD
UPGRADED 
RRD
operating rangef0 (+0.05) MHzf0 (1+0.05) MHz
number of receiving channels23
noise factor of receiving channels7 dB at most6.5 dB at most
transmission coefficient of receiving channels20^25 dB25^28 dB
suppression of radioreceiver
sensitivity on mirror frequencies
-70 dB at least
suppression level of generated noise
interferences that exceed power
of own noises of radioreceiver
20 dB at least
time of auto-equalization-100 ps at most

EQUIPMENT UPGRADING FOR TELEVISION-AND-OPTIC SIGHTING
  Within the upgrading 9W33 (9W38), TOS is replaced with the new combined optical-and-electronic system, which consists of:
  1. television camera;
  2. thermal imaging optical sight;
  3. equipment of automatic target tracking;
  4. equipment for information displaying.
  The upgraded equipment for television-and-optic sighting is intended for fulfi llment the following tasks:
  • detection of low-sized, low-contrast air targets under the conditions of poor light, which are locate in the fi eld of view of television camera and thermal imaging optical sight (TIOS);
  • transmit the signal of digital video image of air targets into the computing system of the UVK cabin;
  • shaping a video image on monitor screens of operators in the UVK cabin;
  • fulfi l an automatic detection of target blip and its automatic tracking;
  • fulfi l a manual tracking of target blip.
  Comparative characteristics of existent and updated equipment for television-and-optic sighting are presented in the Table below.
NAME OF CHARACTERISTICS9W38 TOSUPDATEDUPGRADED RRD
Detection range (if optical visibility is available)20 km100 km30 km
Switched fields of view:
Wide4°50' x 3°38'4°18' x 3°12'6.2°
Narrow1 °27' x 1 °5'1°18' x 1°00'1.45°
Digital enlargement (without reducing
information quality and angular resolution
x2x8
Dynamic range of videosignal receiver-68 dB-
Detector sensitivity-0,0012 Lux-
Operating range of waves--3...5 mm

--25,000 K

UPGRADING OF YHK CABIN
  Within the fi rst stage of the upgrading the UNK equipment, cabin is fallen under the circumstances of substantial changes together with the introduction of digital processing of radio-signals in the UNV cabin. Specialized electronic computing machinery is mounted in the UNK equipment cabin. It is designed to implement following algorithms:
- digital processing of radar signals in proper modes (SMT);
- recalculation of target-designation coordinates in the position of AAMS deploying and their extrapolation; - automatic targets locking for tracking on the basis of target-designation data and information retrieved from searching sectors;
- automatic and semi-automatic tracking of target on the basis of angular coordinates (01 and 02) and range;
- automatic tracking of two guided missiles on the basis of angular coordinates (01 and 02) and range;
- generation of control commands for AAGM guidance;
- preparation of recommendation for AAGM launch (launch device).
  What is more, working stations of the members of combat crew are completely replaced with the automated working stations (AWS). AWS has been implemented on the basis of standard color monitors with keeping of basic operator controls and their placement on consoles, similar to the old working stations. Besides, all functions on control of S-125 AAGM operation remain unchanged.

UPGRADING OF 5P73 S-125M AADMS LAUNCHER
  Purpose and composition
  5P73 launcher is intended for prestart preparation and for launch guidance of 5V24, 5V27, 5V27U or 5V27D missiles.
  Hereby, the launch is designed on the same basis that missiles are. The external appearance of the launcher is presented on picture.
  The launcher consists of the following components:
- tipping unit;
- electric adapter (4 pcs.);
- cradle;
- platform;
- basement;
- vertical guidance mechanism (electric DC motor MM- 52);
- horizontal guidance mechanism (electric DC motor MM- 42);
- prohibited areas mechanism;
- electrical equipment.

TECHNICAL SPECIFICATIONS

NAME OF CHARACTERISTICSVALUE
limits of horizonting± l°30'
loading angle in vertical planefrom 8°20' to 11°
limit missile launch angles:
- in vertical planefrom 4°30’ to 64°30’
- in horizontal planeNo limit
period of transition from transport
mode to combat mode
1 h.

UPGRADED ELEMENTS OF 5P73 LAUNCHER
  Electrical equipment and devices, located inside the launcher, are included into the set of devices which provide remote and local control over drives of vertical and horizontal guidance mechanisms, launch control system testing without missile as well as preparation and launch of the missiles. Hereby, within the upgrading of 5P73 launcher, it will be modifi ed for the application of upgraded missile 5V27D-M.
  Electrical equipment of launcher compiles:
- control unit BU-M;
- digital electric drives of horizontal and vertical guidance mechanisms;
- local sensors;
- topographic positioning equipment.

CONTROL UNIT BU-M
  Control unit BU-M is intended to control the launcher operations in all modes and data interchanges with combat control cabin UNK-M. The control unit BU-M includes:
- launch automation equipment;
- equipment for linkage with UNK-M cabin;
- ground power sources.
  Launch automation equipment and ground power source, located in control unit BU-M, together with equipment located in UNK-M cabin are intended for prestart preparation and missile launch by commands received from UNK-M cabin, as well as for input of prestart preparation data into the UNK-M cabin.
  Herewith, it provides: - preparation of launcher and missiles 5V24 and 5V27 for launch in the modes «Stand-by 2» and «Stand-by 1»;
- preparation of launcher and missiles 5V27U and 5V27D for launch in the modes «30 sec» and «Stand-by 1»;
- preparation of launcher and upgraded missile 5V27D-M for launch, initial setting of inertial system and transfer of fl ight task;
- power supply of equipment of missiles located on launcher with DC current 26V, single-phase AC current 60V with 1000 Hz frequency, single-phase AC current 115V with frequency 1000 Hz, three-phase AC current 36V with frequency 1000 Hz.
  Equipment of interfacing with the UNK-M cabin, besides the abovementioned functions, must provide:
- transfer of fl ight task data from the UNK-M cabin to the upgraded missile 5V27D-M;
- output of data about the pre-launch preparation process of 5V27D-M to the UNK-M cabin.

DIGITAL ELECTRIC DRIVES OF HORIZONTAL AND VERTICAL GUIDANCE MECHANISMS.
  Upgrading of guidance drives means their transferring to digital control principle. Hereby, the executive DC electric motors are replaced for asynchronous AC electric motors.
  Control over executive drive motors is performed by guidance unit, driven by commands and received from the BU-M control unit.
  Application of digital electric drives of horizontal and vertical guidance mechanisms allows considerable increase in dynamic and accuracy parameters of the drives. Comparative parameters of standard and upgraded drives are presented in the Table below.

UPGRADING OF 5V27D MISSILE WITH APPLICATION OF SEMI-ACTIVE SEEKER
  Within upgrading of this type of missile, the following renovations will be performed:
- replacement of the pneumatic steering gear and airleron drives for electric ones, that reduces the weight of unit and increases its control properties;
- installation of semi-active seeker;
- installation of platformless inertial system for guiding the missile to acquisition point by seeker;
- upgrading of the radio receiving unit for providing receiving and deciphering of corrective signals on inertial guidance area (target coordinates in antenna port coordinate system);
- installation of radar proximity fuse based on new component base;
- installation of new missile control unit.

COMPARATIVE CHARACTERISTICS OF STANDARD AND UPGRADED GUIDANCE DRIVES
TECHNICAL PARAMETERS5P73 LAUNCHERUPGRADED LAUNCHER 5P73
speed of drive in guidance mode:
- in horizontal planenot more than 3 deg/snot more than 3 deg/s
- in vertical planeot more than 3 deg/snot more than 3 deg/s
dynamic component of drive error in guidance mode:
- in horizontal plane14 min11 min
- in vertical plane19 min15 min
dynamic component of drive error ar reverse:
- in horizontal plane22 min19 min
- in vertical plane27 min23 min
time of transfer:
- in horizontal plane from 0° to 179°18 sec15 sec
- in vertical plane from 3°25’ to 64°55’16 sec14 sec
static error of drive in horizontal and vertical planes:
- by voltagenot more than 7 minnot more than 5 min
- by scalesnot more than 15 min

  Within the upgraded 5V27D-M1 missile with semi-active seeker, the combined guidance method is achieved:
- on the initial phase of trajectory, an inertial guidance at predicted point with radio correction is applied, with the characteristics from SNR-125M of its velocity and position at target maneuvering;
- on fi nal phase of trajectory, a semi-active self-guidance, after target acquisition with illumination from SNR-125M, is applied.
  Such an upgrade will provide an increase of 5V27D missile far damage envelope up to 40 km (against high-speed and maneuvering targets) and up to 45 km (against smallspeed targets).
  Characteristics of S-125M-2UM AADMS damage envelope in vertical and horizontal planes, for targets fl ying with speed Vt < 300 m/s (Effective refl ective area=1 m2), are presented on Fig. 5 and 6.
  AADMS in vertical and horizontal planes for targets fl ying at speed Vt - 700 m/s (Effective refl ective area = 1 m2) are presented on Fig. 7 and 8.
  Characteristics of damage envelope of C-125M-2UM AADMS in vertical and horizontal planes against targets fl ying with speed Vt < 900 m/s (Effective refl ective area =1 m2) are presented on Fig. 9 and 10.

BASIC SPECIFICATIONS OF SEMI-ACTIVE SEEKER:
TECHNICAL PARAMETERSVALUE
angle rate of target indication 
processing, deg./sec
50
range of target approach speeds, m/s300...2400
weight of semi-active seeker 
components, kg, not more than
15
diameter, mm, not more than200
length, mm, not more than400
duration of radio correction path, ms30,72
mean time between failures, hrs, 
not less than
500

  Target hitting probability by one upgraded missile 5V27D-M1 comprises - p = 0,8. Target hitting probability by two upgraded missiles 5V27D-M1 will be determined by formula:
  p = 1 - (1 - p)2 = 1 - (1 - 0,8)2 = 0,96.
  Application of upgraded missiles 5V27D-M1 allows increase in S-125M AADMS potential in simultaneous tracking of targets and missiles guided at them. The upgraded equipment of antenna post UNV-M and cabin UNK-M provide detection and up to 3 targets tracking, within the beam of SNR- 125M. Upgrading of missile line-of-sight radio transmitter and control command radio transmitter allows for controlling over 6 missiles 5V27D-M1 simultaneously.


UPGRADING OF 5V27D MISSILE WITH APPLICATION OF ACTIVE SEEKER
  Within the upgrading of the missile, the following alterations will be performed:
- replacement of pneumatic steering gear and airleron drives with electric ones, which reduces the weight of unit and increases its control properties;
- installation of active seeker;
- installation of platformless inertial system for guiding the missile to acquisition point by seeker;
- upgrading of the radio receiving unit for providing receiving and deciphering of corrective signals on inertial guidance area (target coordinates in antenna port coordinate system);
- installation of the radar proximity fuse based on the new component base;
- installation of the new missile control unit.
  Within the upgraded missile “5V27D-M2” equipped with the active seeker, proportional modifi ed target guidance method has been achieved:
- inertial guidance with radio correction from SNR-125, on initial stage of missile fl ight and active radar guidance on the fi nal stage;
- inertial guidance without radio correction on the initial stage of missile fl ight and active radar guidance on the fi nal stage.
  This kind of upgrade provides increase in far damage envelope of 5V27D missile up to 40 km against high-speed and maneuvering targets; and up to 45 km against smallspeed targets.
  The damage envelope is intended for targets which fl ying speed is amounted to Vt < 300 m/s (Effective refl ective area = 1 m2), are presented on the Fig.11 and on the Fig.12.
  Damage envelope S-125M-2UM AADMS characteristics, in vertical and horizontal planes for targets fl ying at speed Vt < 700 m/s (Effective refl ective area = 1 m2), are presented on the Fig.13 and on the Fig.14.
  S-125M-2UM AADMS damage envelope characteristics, in vertical and horizontal planes against targets fl ying with speed V, < 900 m/s (Effective refl ective area = 1 m2), are presented on the Fig.15 and 16.

BASIC SPECIFICATIONS OF ACTIVE SEEKER:
TECHNICAL PARAMETERSVALUE
number simultaneously attacked targets1 .... 4
search area, degrees:
- by azimuth± 35°
- by elevation± 25°
angle rate of target indication
processing, deg./sec
50
range of target approach speeds, m/s300 .... 2400
search area by distance, km.0,1 ..... 20
air target acquisition distance (target of
mig-29 type), km, not less than
20
weight of active seeker components, kg,
not more than
15
diameter, mm, not more than200
length, mm, not more than400
duration of radio correction path, ms30,72
mean time between failures, hrs, not
less than
500

  Target hitting probability by the one upgraded missile 5V27D-M2 comprises - = 0,85. Target hitting probability by the two upgraded missiles 5V27D-M2 may be determined by formula:
  P2 = 1 — (1 - P)2 = 1 - (1 - 0,85)2 = 0,977.
  Application of the upgraded missiles 5V27D-M2 allows to increase S-125M AADMS potential in simultaneous tracking of targets and missiles guided at them. In addition, application of the upgraded missiles 5V27D-M2 provides fundamental upgrading of S-125M AADMS. Hereby, the antenna post of the cabin UNV-M has been deleted from the composition of S-125M AADMS and replaced by the standard three-dimensional Radar Station of 36D6 type and radio correction equipment on each launcher. The target detection data is submitted to a digital form to the cabin UNK- M and to the correspondent launcher in the form of usual fl ight task data. The control of missile during the fl ight is completed by missile sighting transponder, placed on the launcher.
  Three-dimensional warning radar station provides detection and tracking of 8 targets (target channels). The launch control system allows controlling over 16 missiles 5V27D-M2 simultaneously.
  The use of the complex phase-code modulated sequence as a sweeping signal of an active HH allows essential reducing of the intentional jamming action on the mentioned missile home head, which defi nitely provides high probability (more than 0.9) of target hitting.
  Applying the radio-correction system and active homehead of the 5B27fl missile instead of the radio-command control system, gives an opportunity to realize the principle of simultaneous target handling capacity, in other words, simultaneous launching of several (4 at most) missiles at different targets in the zone of main lobe of antenna diagram of active HH.

REPLACEMENT OF 5S45 TAKE-OFF BOOSTER
  Replacing the 5S45 take-off booster, solid-fuel charges have to be already are replaced. Besides, 14 cylindrical single-channel explosive cartridges, with usual gunpowder charge, have been replaced with the same single-channel cartridges with combined charge. In comparison with the usual gunpowder charge, the advantage of explosive cartridges with combined charge is the increased time of cartridge burning, while characteristics of developed boost thrust remains the same.
  Applying the cartridges with the combined charge allows fl ights with the aid of take-off booster along all-ballistic trajectory, within the initial trajectory phase of the 5B27fl missile fl ight. Thereupon, the zone edge of lethal envelope of C-125M AAMS amounts to 45 km.
  Profound upgrading of the 5V27D anti-aircraft guided missile permits to prolong its life service up to 10 years. Indeed, this is a fairly preferable alteration, concerning the fact of a long-storing of these missiles, which were manufactures in the former USSR.скачать dle 12.0