FR2700209A1 - Target designation systems. - Google Patents

Description

The present invention relates to the designating systems

  targeting, and in particular to systems for designating a projectile launch system

target marker.

  Frequently, in a modern fight, it is necessary

  that a target chosen by an observer is attacked by a system

  This is of particular importance when the observer is not in a position to launch the most appropriate type of projectile. A typical example of such necessity is the demand by ground troops.

  In such a case one can engage in a bom-

  massive cladding, but there are cases where it is possible to

  choose an isolated target that can be attacked by a single

  jectile For example, it can be asked a plane to destroy

  an isolated tank that may be invisible to the pilot because of a

  hauling or for other reasons The mere use of a radio link to describe the location of the target to the pilot of an airplane

  fast, possibly supersonic, is far from enough.

  With any system of target de lation, it is to be expected that a selected target will try to employ

  countermeasures, both electronic and material. An ef-

  ficace must therefore be able to oppose anyone

  what countermeasures of this kind to ensure correct

the target.

  The object of the invention is to provide a system for designating

  target in a unique and precise manner to a projectile launch system a target selected by a

target marker.

  According to the invention, the target designation system is characterized in that it comprises a target marker capable of

  to select a target, a projectile launching system

  the target must be designated, means for establishing between the target marker and the projectile launching system a two-way communication channel on which pulsed radiation may be

  be transmitted from one to the other by reflection on the selective target.

  and the means of coding the transmitted radiation on the

  communication to uniquely identify the target

  selected at the projectile launch system.

  The expression "projectile launch system" used

  in the present description is intended to encompass all modes of

  yens to launch a projectile on its target It includes, for example, a plane launching guided missiles or ballistic missiles, mouths to

  fire and guided missiles themselves The expression "marker of

  blet 'is used to designate a device to select a

  target Such a device can be mounted on a vehicle.

  An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

  Figure 1 is a schematic illustration of an application

  cation of the invention; FIG. 2 is a partly schematic representation of an apparatus carried by the target marker; FIGS. 3 and 4 are partial representations;

  schematics of devices carried by the product launching system.

jectile.

  Referring to Figure 1, we see a target 10, a mar-

  target 11 and a projectile launching system (eg

  example, an airplane) 12, the target marker 11 carries an infra-red laser

  red light arranged to emit radiation pulses in direct

  The radiation is scattered by the target, and a portion returns to the target marker after a time interval 2 t 2 to indicate the distance of the target. Similarly, a portion of the radiation is detected by the target. 12 when

  the aircraft detects the radiation coming from the target it emits an impulse

  As the radiation from the target marker II has reached the aircraft by reflection on the target, it can be assumed that the radiation from the aircraft reaches the target marker by the same path Si the aircraft emits an impulse at a time t 0, then it reaches the target marker at a time (t + t 1 + t 2) where t and t are the times taken by the radiation to cover the two segments of the path represents in FIG. 1 The equipment of the marker is arranged to respond to the interrogation pulse by emitting another pulse after a delay (tc 2 t 2), where tc is a predetermined part of the delay

  and t 2 is already known from the distance of the target

  the aircraft receives a response to its interrogation pulse after a time interval of (t O + t 1 + t 2) + (tc 2 t 2) + tl + t 2 v

or (t O + 2 t i t C) -

  The aircraft also receives a reflected impulse

  by the target after a time (t O + 2 tl) which indicates the distance

  this of the target in relation to the plane The equipment aboard the a-

  vion is thus able to extract the time tc and confirm that

  this is equal to the predetermined part of the delay.

  firm while the target marker and the aircraft are aiming for the same

target me.

  If the target 10 tries to deceive the aircraft equipment

  by illuminating itself a false target 13, then everything radiates

  emitted from the airplane will not obtain the necessary coded response including the delay part tc, and it will appear that the marker

  target and the aircraft do not target the same target.

  The foregoing description explains the principle of

  The equipment carried by the target marker It is shown in Figure 2 This equipment can be divided

  two sections, one comprising the transmitting and

  The radiation source shown in FIG. 2 is a laser 20, preferably having a solid active medium and emitting infrared radiation. The active medium of the laser is excited by a flash tube 21 controlled by a triggered supply

  Inside the optical resonator of the laser is mounted a

  electro-optical positive 23 which, when actuated by a

  electrical pulse, resonates the optical resonator and causes it to emit infrared radiation via

  an optical telescope system shown schematically at 24.

  A photosensitive device 25 is positioned to receive a portion of the radiated energy to provide a precise indication

  the duration of emission of the laser pulse An optical telescope

  reception, shown diagrammatically at 26, has its optimum axis

  parallel to that of the transmitting telescope 24 and

  ge all radiation received to a photosensitive device 27.

  The output of the device 27 is conveyed by an amplification

  28 at an entrance to each of two AND gates 29 and 30.

  29 for another input the output "rest" of a bistable circuit 31, and the output of the gate 29 is connected to an input of an OR gate 32 The other input of the gate 32 is supplied by a

  impulse generator 33 which generates a continuous train of impulse

  The output of the OR gate 32 constitutes the "action" input for the bistable circuit 31, and the corresponding "action" output is

  connected to the other input of the AND gate 30 The output of the gate

  and ET 30 is connected to the "idle" input of the bistable circuit 31. The "action" output of this bistable circuit is also connected to an input of an AND gate 34 having two inputs whose other input is connected to a source of CP clock pulses The output of

  this door 34 is connected to the input of a counter 35.

  counterparts are connected to a comparator 36 which receives

  also the entries from a register 37 The output of the compa-

  The emitter 36 triggers the electro-optical device 23 of the laser resonator. The outputs of the counter 35 are also connected to a second comparator 38 which also receives inputs from

  a second register 39 The output of the comparator 38 triggers the

  Power supply 22 of the laser flash tube 21 The output of the photosensitive device 25 is conveyed by an amplifier 40 to the input

"resetting" counter 35.

  The operation of the equipment shown in Figure 2 is as follows: The pulse generator 33 is arranged to operate at a predetermined rate, for example 10 pulses per second, which is known, at least approximately, of the equipment of the aircraft A pulse from the generator 33 passes through the OR gate 32 and actuates the bistable circuit 31 The output "action" of the bistable circuit arms the AND gate 34 so that each pulse

  clock is introduced into the counter 35, the frequency

  When the count stored in the counter 35 reaches the value representing a duration (t C-td) set in the register 39, the comparator 38 causes the clock pulse to be much higher than that of the pulse generator. The inputs to the counter 35 continue, and at a time tc later, represented by the value retained by the lightning tube 21.

  register 37, the comparator 36 triggers the electronic device

  optical 23 so that a laser pulse is emitted towards the

  The time tc is a predetermined delay time, while

  the time td is the time taken by the laser to reach the accumula-

  maximum energy release in the active medium after ignition

  of the flash tube The time tc represents the characteristic of

  of the particular target marker.

  When a laser pulse is emitted, the pho-

  to-sensitive 25 detects it and causes the counter to be reset

  Other clock pulses are still applied to the

  which is now intended for measuring the distance from the target On receiving a signal reflected by the target and picked up by the photosensitive device 27, the output of the amplifier 28 is applied to the AND gates 29 and 30. The gate 30 already receives the output "action" of the bistable circuit, and thus the application of the

  signal coming from the amplifier 28 switches the circuit bis-

  The gate 34 is therefore closed and the counter 35 stopped The count recorded in the counter 35 represents the time between the emission of the laser pulse and the

  reception of the reflected signal, ie 2 t 2, and hence indi-

  the distance to the target The "rest" output applied to gate 29 has no effect,

  since the other entry has now stopped The counter remains in the

  until the pulse generator 33 produces its

  next pulse to "operate" the bistable circuit through the gate 32 and restart the process As a result the marker equipment

  continues to emit laser pulses under the action of the gene-

  pulse, and displays the distance to the target.

  The projectile launch system, such as an aircraft, is ready to detect any radiation scattered by the target in its

  field of vision and with the predetermined repetition rate

  When such radiation is received, the aircraft emits an impulse

  interrogation which is reflected by the target towards the mar-

  This impulse is designed to reach the target

  It is possible because the transmission time (t 1 + ty) is measured in microseconds, whereas the time between the pulses of the generator is around

a hundred milliseconds.

  The interrogation pulse is thus received at the target marker while the counter is stopped and holds the count 2 t 2 The output of the detector 27 finds the gate blocked because the bistable circuit 31 is in its "idle" state, but it passes through the gate 29 to actuate the bistable circuit by the gate 32 and open the gate 34 to other clock pulses The counter therefore advances time 2 t 2 to the account t after an interval

  (tc -2 ta) whereupon the laser 20 is turned on as described above.

  The target marker responded to a poll pulse

  of the airplane by itself emitting an impulse after the delay (t -

2 t 2) microseconds.

  Subsequently the target marker equipment is

  prompted by successive interrogation impulses from the

vion.

  The equipment carried by the projective launching system

  the (for example the airplane), represented by FIGS. 3 and 4, is more complicated than that of the target marker and can be divided

  in three sections These are the section of issue and re-

  ception of radiation, the pointing and stabilizing organs

  of the optical system, and the control electronics.

  As in the case of target marker equipment, the radiation source represented is a pumped infra-red laser 50

  by a flash tube 51 which is controlled by a feed de-

  In the optical resonator of the laser, there is an electro-optical device 53 which, when actuated by an electrical pulse, resonates the resonator.

  optics and has it emit infrared radiation

  The optical telescope of reception, preferably of the reflection type, has an optical system represented by a lens 55 which directs the radiation.

  received to a beam splitter 56 A portion of the beam-

  received through the beam splitter onto a

  photo-sensitive device 57, while a portion is reflected on a photosensitive device 58 The device 58 consists of four sectors so that the relative magnitude of the output voltages of the sectors indicates the direction of the incident radiation,

  with respect to the optical axis of the receiving telescope 55.

  The outputs of the photosensitive device 58 are used to control a servo system that directs the optical systems of both telescopes in elevation and azimuth so as to effectively point the two telescopes in the direction of the telescope.

  source of the radiation, ie the target.

  The signal processing circuit 59 receives signals from the four sectors of the detector 58, namely the signals A, B, C and D, and provides three outputs L '. one of these

  last S represents the sum (A + B + C + D) of the four signals, tan-

  say that the other two represent the elevation signal (A + B) -

  (C + D) and the azimuth signal (A + D) (B + C) for the unit asser-

  The latter 60, in addition to the mechanical drive of the two telescopes, provides an error signal which is applied to an inhibition gate 61 which controls the ignition of the laser, and sends a laser ignition signal FL to the circuits of Figure 4 As in the target marker, the laser flash tube is illuminated by

  its power supply 52 before the device 53 of the resonator optimizes

  The photoelectric device 63 is arranged to detect the instant of ignition of the laser. This detector is connected to an amplifier.

  64, whose output is used to sample an ampli-

  65 which receives the output of the photoelectric device 57.

  Sampling is done by a door generator

66.

  The output of the amplifier 64 is connected to the "action" input of the bistable circuit 67. The "action" output of the bistable circuit is connected to an input of each of two AND gates.

  68 and 69 Each of these has a pulse input of hor-

  CP box, and the gate 69 also has an inhibition input coming

  a counter as described below.

  kills the advance input of a master counter 70 The final stage of this

  counter, represented as a separate stage 70 A, at the output

  connected to the muting input of the door 69 The output of the door

  69 forms the input of a second counter 71, the dis-

  The reset input of the distance counter 71 is

  connected to the output of the amplifier 65 The outputs of the

  the different stages of the distance counter are connected to a

  72 and a display register 73 A coding register 74 also has its outputs connected to the comparator 72 The output

  the comparator is connected to the input of the action "of a mono-

  stable 75, the output of which is a "transponder gate" signal TG.

  This signal may suitably be used for resetting the bistable circuit 67 and counters 70 and 71 for the next poll

distance.

  The meter has one more stage than necessary to record the largest possible value of time interval 2 t (see figure 1) between the emission by the airplane of a pulse

  interrogation and the primary echo sent back by the target.

  maximum time will be designated by 2 "

  The control electronics on board the aircraft also includes

  means of authenticating the received signals, means

shown in Figure 4.

  The sum signal S output from the control circuit 59 of the servo signal is applied by an AND gate 100 to a signal selector 101. As indicated, this comprises a two-way parallel gate arrangement. armed door by a signal P, while the other way comprises a divider by two and a door armed by a signal Q The outputs

  both ways go to a monostable circuit and by a trainer of im-

  This pulse is essentially a shift register in which the input pulses are shifted by the clock pulses CP, and are extracted from the pulse.

  register a certain time later The exit of the register of de-

  encoding is applied to a coincidence gate generator 104.

  This is essentially a monostable circuit designed to pro-

  a 300 microsecond gate pulse when it is de-

  latched by a signal from the decoding register The output of the

  coincidence gate generator constitutes an entry of a door

  SE and 105 with two inputs, the other of which is the output of the signal selector 101 The output of the coincidence gate generator 104 also constitutes an input of an inhibition gate 106 whose

  the inhibition input is provided by the output of the monosta-

  The output of the gate 106 forms an input of the AND gate 107. The output of the AND gate 105 is connected to the input.

  "action" of a bistable circuit 108 The output of the decoder register

  Dage 103 is also connected by a pulse former 109 to the "idle" input of this bistable circuit. The "action" and "idle" outputs of the latter are connected to a three-stage shift register 110. The different stages of the shift register 110 are applied to a door system 111, forming a generator.

  signal locking condition such as when the three

  of the shift register are all in a predetermined state, a bistable circuit 112 is "powered" to produce an output SL

"signal lock".

  The bistable circuits 108 and 112, the shift register and the calibration circuit 111 together form a detector

  a triple coincidence represented commenced with an interrupted line.

  The signal lock output, SL, forms another input of the gate 107 and an input of an AND gate 113, whose

  the other input is the output of the signal selector 101

  The gate 113 serves to "operate" a monostable circuit 114 which provides a signal SS which samples the outputs of the servo signal processing circuit 59 (Fig. 3). The signal lock output, SL, also forms an input a

  ET 115, whose other inputs come from the impulse trainer.

  109 and the rest output of the bistable circuit 108 The output

  of the gate 115 is connected to the decoding register 103.

  The sum output S of the signal processing circuit 59

  (Figure 3) is applied to two doors 116 and 117, on this

  as the inhibition input At the other input of each

  these doors, is applied the output TG of the monostable circuit 75.

  The output of the gate 116 is applied to the input "action" of a bistable circuit 118, the output "action" is applied to

  the inhibition input of the AND gate 107 and an input of

  The bistable circuit 118 has its input

  pos "connected to the output FL of the door 61 (Figure 3) The other input of the door 119 is the output of the door 117, which provides

  also a reset signal of the RS system sent to different

  units shown in Figures 3 and 4 The output of the

  gate 119 is connected to the offset input of a JK flip-flop 120.

  The outputs of the latter are the control signals P and Q

  signal selector doors 101.

  The output of the gate 116 is also connected to an input of an OR gate 121 whose other input is connected to the output of the gate 105. The output of the gate 121 forms an input of an AND gate 122, whose other entrance receives exit "rest"

  of the bistable circuit 112, and it also forms the input of

  to zero of an auxiliary counter 123, clocked by the clock pulses CP The output of the gate 122 forms the "action" input of a bistable circuit 124, whose input "rest" is the output of the counter auxiliary 123 The "action" output of the bistable circuit

  124 is connected to the decoder register 103 The output of the

  The auxiliary driver 123 forms the LF input "laser ignition" of the gate 61 (FIG. 3). The output of the AND gate 107, as well as the

  output SL of the bistable circuit 112 and the output TG of the single circuit

  75, form the inputs of the OR gate 125, the output of which constitutes the second input of the AND gate 1000. As mentioned above, the operation of the equi-

  FIGS. 3 and 4 consist in detecting the

  nally reflected by a designated target, query the

  target, at the same time measure the distance from the target, and finally

  detect a response from the target marker and verify the

  While the plane is waiting for a train

  of laser pulses from the target, the equipment of the

  FIGS. 3 and 4 are placed in its initial conditions. The bistable circuit 67 is at rest and the master counter 70 and the counter

  71 are set to zero. The required coding delay is

  in the coding register 74, and the display register 73 is cleared. The decoding register 103 is cleared and the register

  offset 110 of the coincidence detector is reset to zero.

  JK 120 is set to the desired state, for example to give the

  output P to the signal selector 101.

  The receiving telescope on board the aircraft is arranged in such a way that the sector detector 58 has a large field of view, while the detector 57 has only a narrow angle. Therefore, assuming that a target is detected while the telescope is out of alignment, only the detector 58 will receive the incident pulse train Even in the rare eventuality

  of a perfect alignment of the telescope, the amplifier 65 is

  the lack of a sampling impulse from the general

distance door operator 66.

  The incident pulses detected by the detector 58 are applied in the form of the output S by the signal processing circuit 59 and via the gate 100 to the signal selector 101. The gate 100 is opened by the presence of the output SL of the bistable circuit 112 and a signal passes through the stage 101 by the channel containing the armed gate by the signal P coming from the flip-flop 120 The output of the selector 101 is routed

  by the pulse former 102 to the decode register 103

  it is arranged to detect recurrent pulses at the cadenza

  this preset, and such pulses crossing the decoding register 103 are applied to the coincidence gate generator

  104 The latter generates a verification pulse of 300

  croseconds for each pulse received, these test pulses

  The other input of the AND gate 105 is the output of the signal selector. Therefore, if the pulses from the coincidence gate generator are

  produced by an authentic impulse received from the

  As a result, they will coincide with the pulses received later through the signal selector. The output of the resulting gate 105 is applied to the bistable circuit 108 and thence to

  shift register 110 The output of gate 105 also crosses

  OR gate 121 for triggering auxiliary counter 123 and, applied together with signal SL of bistable circuit 112 to gate 122, it "drives" bistable circuit 124. The output of the latter clears decoding register 103 for a time determined by the auxiliary counter 123 which then puts the bistable circuit 124 at rest. The erase signal applied to the decoding register prevents the output from the decoding register of pulses other than those arriving at the expected time determined by the clock rate. preset impulse *

* The above process is repeated until three

  cidence between generator coincidence gate pulses

  104 and the pulses of the signal selector 101 have been detected

  It is then assumed that the received pulse train is authentic, and the calibrating circuit 111 "actuates the bistable circuit 112 to give the latch output of the signal S Lo The disappearance of the signal SL from the gate 125 closes the door but the new signal SL applied to the gate 107 allows the exit of the coincidence gate to open the door 100 by the gates 106 and 107 only during the duration of a coincidence gate pulse All pulses outside this duration are excluded from the decoding register 103 pa 27 | r 9 LV Ictionne

  of the monostable circuit of the signal selector 101 The absence

  signal SL also prevents the generation of impulse

  later by the bistable circuit 124, since the gate 122 is now closed

  Signal SL is also applied to gate 113,

  time as the selected outputs of the signal selector 101.

  This allows the monostable circuit 114 to be actuated for a

  short duration to provide the SS signal to sample the

  from detector 58 and apply the control signals to the

  slave circuit 60 Each incident pulse is now exchanged

  and the slave control goes into action until the telescope is pointed directly at the apparent source of

  impulses, in this case the target that reflects the impulses

the marker.

  When the servo error is canceled, the gate 61

  the next LF output of the auxiliary counter 123 and

  The ignition 52 of the laser and the flash tube 51 are triggered by the output of the gate 61, followed, after a short delay determined by the

  delay 62 ,, - by the activation of the electro-optical device 53

  it allows the emission of a laser pulse of maximum intensity

by the telescope 54.

  The emission of the laser pulse is determined by the detector 63 which actuates the distortion gate generator 66 to allow the amplifier 65 to carry an expected echo

  in return, and it also actuates the bistable circuit 67

  The "action" portion of this circuit arms gates 68 and 69, and consequently allows clock pulses CP to apply to the master counter

70 and the distance counter 71.

  The primary echo from the target is detected by the detection

  57, passes through the amplifier 65 and resets the counter 71 If there are several primary echoes, for example from a cloud, the distance counter is reset by each This is necessary since, under these conditions , it is the last received primary echo that comes from the target Then, after the reception

  the last primary echo, the distance counter stops the

  master on an account representing the time interval 2 t 1

  (FIG. 1) The output of the distance counter 71 is likewise

  When the master counter 70 has counted to its maximum, that is to say after one: duration of 80 microseconds, the output of the additional stage 70 A changes, while the meter starts again

  for a new count of 80 microseconds The appearance of

  of the floor 70A blocks the door 69 and prevents the application of

  clock pulses subsequent to the distance counter 71 At the same time the display register is caused to record the account

  accumulated in the distance counter using it as a

  distance of the target (in complementary form).

  When the master counter has counted up to (t O + 160) microseconds, it returns to zero, thus removing the inhibition input

  of the door 69 and allowing the distance counter 71 to restart

  The distance counter therefore restarts with a value representing

  both a time (80 2 t,) microseconds up to the value entered

  in the coding register 74 This value represents (t -80) half

  croseconds since the distance counter is kept stopped for

  allow the transfer of its contents to the posting register 73.

  When the count of the distance counter 71 is equal to the count

  introduced into the coding register 74, the comparator provides an output which "actuates" the monostable circuit 75 to produce a

  TG transponder gate pulse with a duration of 100 nanosecon-

  The signal TG opens the door 100 by the OR gate 125 at a time

  o an answer is expected If an answer is received during the

  TG pulse, then the gate 116 prevents any change in state of the JK 120 rocker and starts the counter 123 by the door 121 This causes the ignition of the laser of the aircraft a second time, and the above process is repeated Door 116 also blocks the

  door 107 so that the door 100 only opens during the

  the application of the narrow pulse TG by the gate 125.

  The foregoing description assumed that all conditions

  required for the operation of the equipment are satisfactory

  There are, however, several cases where other situations may

to introduce themselves.

  One of these relates to the condition of the signal lock resulting from the detection of three successive coincidences between the signals from the selector 101 and the coincidence gate signals from the generator 104. The bistable circuit 108 is continuously recalled at rest. by the pulses of the decoding register 103 through the pulse former 109, and the required count is reached only if the required coincidences occur. The coincidence detector must be continuously actuated, and if two of the expected coincidences occur the bistable circuit 112 is reset at rest to produce the output SL A missed coincidence also means that the gate 100 is

  closed and that no input impulse can appear in the re-

  decoding box This stops the clock input on the regis-

  coincidence shift 110 since there is no more input to the pulse former 109 To maintain the output SL during a

  missed coincidence in order to avoid the previous situation, the last

  exit from the coincidence gate is added to the SL signal and that of the shift register clock on the gate 115,

  then applied to the decoding register as an "artifi-

  Another possible situation is that no pulse is received by the detector during the brief gate signal.

  transponder TG from the monostable circuit 75 This may occur

  re if, in addition to the desired signal corresponding to the real target, spurious signals at the correct repetition rate arrive

  during the duration of the coincidence gate 104 because of a different

  fusion by a cloud, or by particularities of the terrain, or at

  because of the countermeasures of the target In the case where the first

  general to which the selector 101 is intended to respond is a para-

  site, arriving may be from a different direction from that of the

  target, the signal lock can be obtained but no

  In this case, the gate 117 operates in place of the gate 116. As a result, the state of the JK 120 flip-flop changes to modify the selector signal selection logic. 101 In the example shown

  disappearance of the signal P and its replacement by the signal Q introduced

  second pulse I in that the first pulse is removed by the two-divider circuit of the selector and the second signal

  Coincidence door is selected instead.

  the new signal usually requires a realignment of the laser telescope in a new direction, and the abandonment of all distance data from the first signal, it is

  desirable to put the system back into its original conditions

  This replacement is obtained by applying the

  the gate 117 as a reset signal RS to all the recalibile elements which have not already been recalibrated by the transponder gate signal TG The signal acquisition sequence is then repeated as above except that a new signal selection mode is established by the presence of the signal Q instead of the signal

  P The system will alternate between the two modes of selecting the

  general in the hope of collecting a train of authentic impulses.

  The use of first and second pulse logic is just one way to change the signal selection mode.

  system can be designed to meet any

  required signal, and to alternate between two or more

the latter.

  The above description refers to a mode of implementation

  It is clear that the logic can be modified, and that other refinements can be added.

  to oppose the different countermeasures employed by the

  The final result of the system described is a measure of distance and direction, since the laser of the aircraft must finally be pointed straight at the marked target.

  serve to directly control the projectile system.

Claims (28)

R E V E N D I C A T IO N S 2700209   A target designation system characterized by comprising a target marker capable of selecting a target, a projectile launch system to which the target is to be designated, means for establishing between the target marker and the target marker.   projectile launch system a bilateral communication channel   on which pulsed radiation can be transmitted from one to the other by reflection on the selected target, and means of   to encode the transmitted radiation on the communication channel of   to uniquely designate the target selected in the system. projectile launching system.   System according to claim 1, characterized in that   what the target marker includes a laser capable of emitting   radiation to the target and a sensitive detector   radiation likely to receive radiation from laser reflected by the target.   3 System according to claim 2, characterized in that the detector sensitive to radiation carried by the marker   target is equipped with an optical system whose optical axis is   parallel to that of the laser carried by the target marker.   System according to any one of the claims   1 to 3, characterized in that the projectile launching system comprises a laser capable of emitting radiation towards the target and a radiation sensitive detector capable of   receive the laser radiation reflected by the target.   System according to Claim 4, characterized in that the radiation-sensitive detector carried by the projectile launching system is provided with an optical system whose optical axis is parallel to that of the laser carried by the system. projectile launch.   System according to any one of the claims   4 or 5, characterized in that the radiation-sensitive detector carried by the projectile launching system is sensitive to   the direction of incidence of radiation reaching it.   System according to any one of the claims   4 to 6, characterized in that the projectile launching system comprises means capable of preventing the emission of its own laser except when the optical axis of the laser is directed towards   an apparent source of radiation.   System according to any one of the claims   1 to 7, characterized in that the coding means carried by the target marker comprise means for sending to the laser carried by the latter a train of radiation pulses   at a predetermined rate of repetition until a pulse   radiation is received by its sensitive detector.   yonnement. System according to claim 8, characterized in that   what the coding means carried by the target marker com-   also take means capable of responding to a received radiation pulse to emit a single pulse of radiation after a preset time.   Coherent system according to any one of the claims   1 to 9, characterized in that the coding means carried by the target marker comprise means for determining the distance from the target to the target marker   System according to any one of the claims   1 to 10 characterized in that the coding means carried by the projectile launching system comprise means capable of responding to the detection of a train of radiation pulses having a predetermined repetition rate to generate a train of verification pulses.   System according to claim 11, characterized in that the encoding means carried by the projectile launching system also comprise means capable of responding   has a required number of coincidences between the verification impulses   cation and radiation pulses detected to emit   laser a single pulse of radiation.   System according to any one of the claims   1 to 12 characterized in that the encoding means carried by the   projectile launch system include means of deter-   undermine the distance from the target to the projec- the.   System according to any one of the claims   2 to 13, characterized in that each laser is capable of emitting   be infra-red radiation pulses.   System according to any one of the claims   2 to 14, characterized in that each laser is a communication device   mutation of the overvoltage coefficient.   16 Target Marker for a Designation System of   target according to claim 1, characterized in that   takes a laser capable of emitting radiation towards the target and a radiation sensitive detector capable of   to receive laser radiation reflected by the target.   Target marker according to Claim 16, characterized in that the coding means comprise means for sending a radiation pulse train to the laser.   at a predetermined rate of repetition until an impulse   radiation is received by its sensitive detector. yonnement.   Target marker according to claim 17,   characterized in that the coding means also comprises means capable of responding to a received radiation pulse in order to make the laser emit a single pulse of radiation after a preset time.   19 Target marker in accordance with any of the   16 to 18, characterized in that it comprises means   to determine the distance from the target to the target marker.   A projectile launch system for a target designation system according to claim 1, characterized in that it comprises a laser capable of emitting radiation towards the target and a radiation sensitive detector capable of   to receive laser radiation reflected by the target.   21 Projectile launching system in accordance with   20, characterized in that the radiation-sensitive detector is sensitive to the direction of incidence of the radiation who reaches it.   22 Projectile launching system complying with one   any of claims 20 or 21, characterized in that the   encoding means comprise means capable of responding to the de-   sensing a radiation pulse train having a predetermined repetition rate to generate a pulse train of verification.   23 Projectile launch system conforming to the   22, characterized in that the coding means comprise   also means that can meet a requirement of coincidence   between the verification pulses and the pulses of   radiation detected to make a single laser pulse radiation.   24 Projectile launch system complying with one of   any of claims 20 to 23, characterized in that the   encoding means comprise means for determining the distance   from the target to the projectile launch system.