GB2246207A - "process for harmonization between an aiming telescope, a heat camera and a guidance projector." - Google Patents

Description

PROCESS FOR HARMONIZATION BETWEEN AN AIMING TELESCOPE, A HEAT CAMERA AND A GUIDANCE PROJECTOR.

The invention relates to a process for harmonization between an aiming telescope, a heat camera and a guidance projector, the said telescope including an objective, a reticle visibly illuminated and an eyepiece, the said camera of "wavelength transformer" type including input optics and output optics which project the visible image of the scene after reflection on a dichroic plate to infinity along the axis of the telescope.

This system is intended to operate a fire control system.

The laser beam guidance projector illuminates a guidance tunnel centered on the line of sight.

The object of the process of the invention is to provide permanent control of the harmonization before and during the firing of a missile between the axes of the guidance laser beam, the aiming telescope and the heat camera by means of operations not necessitating the use of any specific equipment.

This object is obtained by the process of the invention which is characterized in that the said telescope is integral with a plate with parallel faces to form a stable reference assembly, the said plate being adjusted by construction perpendicular to the optical axis of the telescope and the said adjustment being capable of being controlled by observing through the eyepiece the coincidence of the reticle and of its image obtained by autocollimation on the said plate, the said guidance projector having its axis servo-controlled so that it is always perpendicular to the said plate, the said camera being positioned in front of the aiming telescope and its harmonization being carried out by adjustment of its positioning with respect to the said stable reference assembly.

If the heat camera has a magnification other than + 1, another plate with parallel faces situated at the output of the visible channel is adjusted by construction perpendicular to the invariant axis of the camera. The adjustment of its positioning is carried out by modifying its orientation in such a way that the aiming reticle coincides with its image formed by autocollimation on this other plate with parallel faces.

If the heat camera has a magnification equal to + 1, the adjustment of its positioning can be carried out with no accuracy limitation.

The following description referring to the appended drawing, both given by way of example, will give a good understanding of how the invention can be embodied.

The single figure shows the basic diagram of the principle of the system for the implementation of the harmonization process according to the invention.

The day telescope 1 is integral with a transparent plate with parallel faces 2 in such a way as to form a stable reference assembly. The aiming axis 3 of this telescope defined by the objective 4 and the reticle 5 is adjusted by construction perpendicular to the reference plate 2. A light source 6 illuminates the reticle 5 by reflection on a semitransparent plate 7. The observer 8 can thus check through the eyepiece 9 that the image of the reticle 5 coincides with the reticle after autocollimation on the plate 2 when the source 6 is powered.

The guidance beam projector 10 is constructed so that its guidance axis 11 is always perpendicular to the plate 2. A control system in the guidance transmitter which performs this function is described in patent application No 85,18,467 in the name of the Applicant, filed at the same time as the present application.

The heat camera 12 of "wavelength transformer" type is placed in front of the aiming telescope 1. It includes IR input optics 13, and output optics 14 which project to infinity the visible image of the scene after reflection on a dichroic plate.

The harmonization process varies slightly depending on the type of camera.

If the heat camera has a magnification other than + 1, or has several fields and several magnifications at least one of which is other than + 1, it must have an accurate angular position with respect to the aiming telescope in order not to modify the aiming direction.

The camera is then fitted with a plate with parallel faces 18 situated at the output of the visible channel which is adjusted by construction in such a way that the invariant axis of the heat camera is perpendicular to this plate.

The name invariant axis of a camera, with a magnification other than + 1, is given to the direction of image space for which the input and output rays are parallel.

If 17 is the invariant axis, the input 16 and output 17 axes of the camera are parallel. The plate 18 has been adjusted by construction perpendicular to the axis 17. In these conditions the plate 18 is parallel to the plate 2 of the aiming telescope.

The harmonization of the heat camera with respect to the aiming telescope therefore consists in adjusting the orientation of the heat camera 12 until the image of the reticle 5 coincides with the reticle after autocollimation on the plate 18.

This operation can easily be carried out by the observer 8 without using any specific equipment outside the firing post.

The axes 3 of the telescope, 11 of the guidance projector and 16 of the heat camera are parallel to each other.

The changing of the field of the heat camera does not modify the harmonization.

If the heat camera has a magnification of + 1, the input 16 and output 17 axes are parallel by construction.

The same applies to all the field rays at the input and output of the camera.

The camera can be positioned without any accuracy in front of the aiming telescope 1 since the camera is equivalent to a plate with parallel faces which would have the property of changing the wavelength of the radiation passing through it.

The system described above is also appropriate to a fire control system permitting firing at moving targets.

It is then necessary to make firing corrections computed by a computer which takes account of the different parameters such as target range and velocity, weapon velocity, atmospheric parameters...etc...

The purpose of the corrections is to make the missile fly on a trajectory that is angularly offset with respect to the line of sight of the target. A deviation element 19 is therefore placed in front of the guidance projector in order to deflect the guidance axis 11 by the angle determined by the fire control computer.

The firer 8 continues to aim at the target. The deviation element 19 can be either a mirror, a diasporometer or any other deviation system servo-controlled by the firing computer.

Claims (4)

1. Process for harmonization between an aiming telescope, a heat camera and a guidance projector, the said telescope including an objective, a reticle visibly illuminoted and an eyepiece, the said camera of "wave-length transformer" type including input optics and output optics which project to infinity along the axis of the telescope the visible image of the scene after reflection on a dichroic plate, characterized in that the said telescope is integral with a plate with parallel faces to form a stable reference assembly, the said plate being adjusted by construction perpendicular to the optical axis of the telescope and the said adjustment being capable of being controlled by observing through the eyepiece the coincidence of the reticle and of its image obtained by autocollimation on the said plate, the said guidance projector having its axis servo-controlled so that it is always perpendicular to the said plate, the said camera being positioned in front of the aiming telescope and its harmonization being carried out by adjustment of its positioning with respect to the said stable reference assembly.

2. Process according to Claim 1, wherein the heat camera has several fields or several magnifications at least one of which is other than + 1, characterized in that another plate with parallel faces situated at the output of the visible channel having been adjusted by construction perpendicular to the invariant axis of the camera, the said adjustment of its positioning is carried out by modifying its orientation in such a way that the aiming reticle coincides with its image formed by autocollimation on the said plate with parallel faces placed at the output of the visible channel of the camera.

3. Process according to Claim 1, wherein the heat camera has a magnification of + 1, characterized in that the said adjustment of its positioning can be carried out with no accuracy limitation.

4. A process for harmonisation between an aiming telescope, a heat camera and a guidance projector substantially as described hereinbefore with reference to and as shown in the accompanying drawing*.

4. A process for harmonisation between an aiming telescope, a heat camera and a guidance projector substantially as described hereinbefore with reference to and as shown in the accompanying drawing.

5. Any other novel feature or combination disclosed hereinbefore or shown in the accompanying drawing..

AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWS.

1. Process for harmonization between an aiming telescope, a heat camera and a guidance projector, the said telescope including an objective, a reticle visibly illuminated and an eyepiece, the said camera of "wave-length transformer" type including input optics and output optics which project to infinity along the axis of the telescope the visible image of the scene after reflection on a dichroic plate, characterized in that the said telescope is integral with a plate with parallel faces to form a stable reference assembly, the said plate being adjusted during rnanuiacure zo Ine or & ter/ perpendicular to the optical axis of the telescope and the said adjustment being capable of being checked by observing through the eyepiece the coincidence of the reticle and of its image obtained by autocollima- tion on the said plate, the said guidance projector having its axis servo-controlled so that it is always perpendicular to the said plate, the said camera being positioned in front of the aiming telescope and its harmcni- zation being carried out by adjustment of its positioning with respect to the said stable reference assembly.

2. Process according to Claim 1, wherein the heat camera has several fields or several magnifications at least one of which is other than + 1, characterized in that another plate with parallel faces situated at the output of the visible channel having been adjusted by construction perpendicular to the invariant axis of the camera, the said adjustment of its positioning is carried out by modifying its orientation in such a way that the aiming reticle coincides with its image formed by autocollimation on the said plate with parallel faces placed at the output of the visible channel of the camera.

3. Process according to Claim 1, wherein the heat camera has a magnification of + 1, characterizec in that the said adjustment of its positioning can be carried out with no accuracy limitation.