CA1231264A - Target image presentation system - Google Patents
Target image presentation systemInfo
- Publication number
- CA1231264A CA1231264A CA000453987A CA453987A CA1231264A CA 1231264 A CA1231264 A CA 1231264A CA 000453987 A CA000453987 A CA 000453987A CA 453987 A CA453987 A CA 453987A CA 1231264 A CA1231264 A CA 1231264A
- Authority
- CA
- Canada
- Prior art keywords
- film
- images
- frames
- predetermined
- aircraft
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B41/00—Special techniques not covered by groups G03B31/00 - G03B39/00; Apparatus therefor
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B15/00—Special procedures for taking photographs; Apparatus therefor
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B15/00—Special procedures for taking photographs; Apparatus therefor
- G03B15/08—Trick photography
Abstract
ABSTRACT
TARGET IMAGE PRESENTATION SYSTEM
A method of producing a cine film is disclosed, the film being for use in a target image presentation system to provide a representation of a moving object as seen by an observer, the method comprising displaying a model of the object, photographing images of the model onto a first film, photographing images from the first film onto a second film the images having orientations corresponding to those of the object as it would be seen by the observer, and adjusting the sizes of the images on the second film to simulate variations in the range of the object from the observer. The specification also discloses apparatus for producing the films used in the system, and systems in which the films are used.
TARGET IMAGE PRESENTATION SYSTEM
A method of producing a cine film is disclosed, the film being for use in a target image presentation system to provide a representation of a moving object as seen by an observer, the method comprising displaying a model of the object, photographing images of the model onto a first film, photographing images from the first film onto a second film the images having orientations corresponding to those of the object as it would be seen by the observer, and adjusting the sizes of the images on the second film to simulate variations in the range of the object from the observer. The specification also discloses apparatus for producing the films used in the system, and systems in which the films are used.
Description
~;~3~
T~RGET_IMAGE PRESENTATION SYSTEM
BACKGROUND OF THE INVENTION
Field of the Invention the present invention relates to a target image presentation system in which the image of a target is provided on a cinematograph film and is projected from the film on to a screen by a cinematograph projector.
Description of the Prior Art In a target acquisition training system which has been proposed, a target image presentation system displays images of a target aircraft on the interior surface of a part-spherical dome in such a manner as to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile within a air space surrounding the observer. The target image presentation system includes a cinematograph film bearing on successive frames of the film target image corresponding to those which would be viewed by a ground observer within the dome at successive fixed time intervals during the flight of the aircraft in the predetermined flight profile, a cinematograph projector which projects images from the film in an image carrying beam and an image beam deflection assembly which directs the image carrying beam to positions on the dome corresponding to the positions of the aircraft flying the predetermined flight profile.
In the target acquisition training system hereinbefore described, the cinematograph film used has been produced using a cinematoyraph camera directed via a mirror on to an aircraft flying a predetermined flight profile to be represented and simultaneously recording signals representing the azimuth and elevation of the ,~,..~0,' L26~
aircraft during the shooting of the film. The film is then processed to produce a master from which one or more copies are made. The copy is then used in the cinematograph projector in the dome and means are provided for moving the image beam deflection assembly in accordance with the recorded azimuth and elevation signals and arranging to synchronise the image beam deflection with the projection of images from the film so as to produce on the dome a moving image simulating the flight of the aircraft.
Description of the Prior Art The projection of target aircraft images on to the surface of the dome in the manner described has been regarded as satisfactory for the development of tracking skills by trainee anti-aircraft gunners, but the production of the films has been costly and as a result confined to a few simple aircraft flight profiles. It is an object of the present invention to provide a cost effective method of producing a cinematograph film which meets the above-mentioned need.
It is a further object of the present invention to provide a cinematograph film produced by the method and a target image presentation system including a cinematograph film so produced.
It is yet another object of the present invention to provide apparatus for producing a cinematograph film by the method.
According to a first aspect of the present invention there is provided a method of producing a cinematograph ~L~3~Z'~
film for use in an image presentation system in which images are projected on to a screen to provide for an observer viewing the screen a visual representation of an object moving in a predetermined path relative to the observer, the method comprising the steps of displaying a model of the object, photographirlg on to a first photographic film images of the model in a manner such that different frames of the film display images of the object at different orientationC~ photographing on to successive frames of a second photographic film images carried on frames of the first film to produce a sequence ox images on the second film having orientations corresponding to those of the object as would be viewed by an observer during movement of the object in the predetermined path relative to the observer while adjusting the sizes of the images on the frames of the second film to simulate variations in the range of the object from the observer.
Preferably, the cinematograph film is intended for use in an image presentation system in which the images of a target aircraft are projected on to the interior surface of a part-spherical dome to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile within an air space surrounding the observer, and in which cinematograph projection means projects images from the cinematograph film in an image-carrying beam and directs the image carrying beam to positions on the dome corresponding to the positions of the aircraft flying the predetermined flight profile. The images produced on the second film then have line of sight orientations corresponding to those which would be ~3~26~
viewed hy an observer during movement of the aircraft flying the predetermined flight profile. The cinematograph projection means preferably comprises a stationary projector for projecting the image carrying beam and an image beam deflection assembly for directing the beam on to the dome.
In the embodiment of the invention hereinafter to be described the images of the model aircraft are photographed on to the first film in a sequence in which successive images have orientations corresponding to those successively taken up during movement of the aircraft in the predetermined flight profile and are transferred to the second film in the same sequence, while adjusting the sizes of the images to simulate variations in the range of the aircraft from the observer. It will however be appreciated that in some circumstances it may be considered preferable to produce a library of slides in which the images have orientations whi.ch could be selected for any one of a large plurality of different target flight profiles, selecting from the library those slides having images with orientations appropriate for a particular flight profile and photographing on to the second film the images on the selected slides in a sequence required for that flight profile.
The model is preferably a reduced scale model of the aircraft and is supported on a gimballed model support structure for angular displacement about its pitch, yaw and roll axes and the images of the model are photographed on to the first film by a photographic ~3~Z6~
camera 1ocated at a fixed distance from the model support structure.
In a preferred embodiment of the invention, the images carried by the frames of the first film are photographed on to the frames of the second film by individually mounting each frame in a slide; placing each slide in turn in a fixed slide support structure and photographing the image carrying frame of each slide on to the second film using a second photographic camera, while adjusting the second camera to vary the size of the image transferred on to the second film.
Preferably, the size of the image transferred on to the second film is varied by varying the range of the second camera from the slide support structure.
While a considerable reduction in the cost of film production can be made by photographing a model of the aircrafl: iTI place of an actual aircraft in accordance with the first aspect o the invention, the production cf the film in this way needs to be carried out to exacting standards and is very time-consumin~. As a result, one film is produced bearing several target flight profiles of one aircraft type and copies of this film made and supplied with the target acquisition training systems when sold. The systems are however widely used throughout the world and a film suitable for use in training personnel of one armed force who would recognise the aircraft as an enemy aircraft would be unsuitable for use by personnel of another armed force who would recognise the aircraft type as friendly. Furthermore, training in aircraft recognition can only be advanced by providing target ~z~3L2i~
flight profiles of aircraft of many different types and providing the facility of selecting a sequence of profiles in which the aircraft type changes from one profile to the next.
The use of sound effects simulating aircraft noise and anti-aircraft gun-fire and the use of actual weapons in the dome modified to simulate firing have produced a realistic environment for a gunner, but it has been found that it falls far short of an environment likely to be experienced in a real multiple aircraft attack in which aircraft of different types are overflying the air space in different directions in rapid succession and executing different manoeuvres and where a choice needs to be made by the gunner as to which aircraft to engage.
While several target aircraft flight profiles can be included on one cinematograph film, there is the disadvantage that the order in which the profiles are projected is fixed, unless provision is made for selectively accessing the target flight profiles on the film. To reduce the average access time it has been proposed to employ a continuous motion projector incorporating a holoscope rotating prism. The projector film capacity can be made of the order of 720 metres (2,400 feet) providing a maximum running time of 60 minutes at 25 frames per second if target flight profiles are projected in consecutive order from the film. The maximum access time from the end of the first profile to the start ox the last is six minutes at lO times normal running speed, with normal average access time between selected target flight profiles ~;~3~6~
which are non-consecutive in the region of 30 to 60 seconds.
Chile the use of a continuous motion film projector as described makes it possible to vary the sequence in which the target flight profiles are projected, it has been found that the access time between flight profiles in a selected sequence is frequently too long and does not adequately represent circumstances in a real attack situation.
It will be apparent that there is a need for a target flight profile film which can be produced readily and at low cost, which bears a multiplicity of target flight profiles of wide variety and in which alternative sequences of the profiles can be accessed from the film without unacceptable access times.
According to a second aspect of the invention, there is provided a method of producing cinematograph film according to the first aspect of the invention and including the step of reducing on the second film the number of frames carrying images representing the predetermined target flight profile by omitting one or more frames which would succeed a predetermined frame in the target flight profile and which would carry images whose orientations do not deviate from that of the image of the predetermined frame by more than a predetermined amount and providing stored information as to omitted frames, whereby the cinematograph ~L23126~ 1 projection means can be control]ed to hold the predetermined frame for a projection time equivalent to that interval which would be required for the projection also of the omitted frames.
Additionally or alternatively the method according to the second aspect of the invention includes the step of reducing on the second film the number of frames carrying images representing the target flight profile by omitting one or more frames which would succeed a predetermined frame in the target flight profile and which would carry images whose sizes do not deviate from that of the image of the predetermined frame by more than a predetermined amount and providing stored information as to omitted frames, whereby the cinematograph projection means can be controlled to hold the predetermined frame for a projection time equivalent to that interval which would be required for the projection also of the omitted frames.
By introducing the step of omitting one or more frames from the film, it has been found that the length of the target flight profile on the film can for many profiles be markedly reduced without any apparent loss of image recognition by a gunner tracking the target image when projected as hereinbefore described.
According to a third aspect of the present invention there is provided a cinematograph film produced by the method accordirlg to the first or second aspect of the invention.
~ccordlng to a fourth aspect of the invention there is provided t:arget image presentation system in which the images of a target aircraft are projected on to the interior surface of a part-spherical dome to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile withi.n an air space surrounding the observer, and in which cinematograph projection means projects images from a cinematograph film in an image-carrying beam and directs the image carrying beam to positions on the dome corresponding to the positions of the aircraft flying the predetermined flight profile, a cinematograph film produced by a method according to the second aspect of the invention, and means responsive to the stored information as to omitted frames to control the advancement of the cinematograph film through tlle projection means whereby the image of the predetermined film frame is projected for an extended period to compensate for the omitted frames in the film.
; 25 according to a fifth aspect of the present invention there is provided apparatus for producing a cinematograph film by the method according to the first aspect of the invention for use in an image presentation system in which the images of a target aircraft are projected on to the interior surface of a part-spherical dome to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile within an air space ..~ .,~
69 f ;3 ~L23~L26a~
surroundiny the ohserver, and in which cinematograph projection means projects images from a cinematograph film i.n an i.mage-carrying beam and directs the image ; carrying beam to positions on the dome corresponding to the posi.tions of the aircraEt flying the predetermined flight profile, the apparatus comprising a model support structure for supporting the model $or angular displacement about its pitch, yaw and roll axes, means for angularly displacing the model on the structure about its pitch, yaw and roll axes, a first photographic camera mounted at a fixed range from the model support structure for photographing on to a first photographic film images of the model in a manner such that different frames of the film display images of the ]5 model at different orientations, a second photographic camera for photographing on to successive frames of a second photographic film the images carried on frames of the first film to produce a sequence of images on the second fi.lm having line of sight orientations ; 2~ correspotlding to those which would be viewed by an observer during movement of the aircraft flying the predetermined profi.le, the second camera being so mounted as to include provision for adjusting the range of the second camera from the second film, wherehy the sizes of the i.mages on the frames of the second film can be vari.ed to simulate variations in the slant range of the aircraft from the observer, and computing apparatus responsive firstly to input flight path data to gellerate and store in a first data file data representing the aircraft's position and orientation with respect to earth coordinates at successive time intervals during the flight of the aircraft in the flight profile, secondly to data in the first data file ,, , . I, "I.
~23~L2~i~
to generate and store in a second data file data representing the aircraft's line of sight orientation and slant range with respect to a predetermined datum position at the successive time intervals and thirdly to data in the second data file to generate a first script to be utilised by an operator of the first photographic camera and which provides a sequence of pitch, roll and yaw settings for the model applicable t.o successive time intervals in the profile and to generate a second script to be utilised by an operator of the second photographic camera and which provides a sequence of settings for the ranqe of the second photographic camera from the frame of the first film to he photographed applicable to the successive time intervals in the profile.
It will be appreciated that the time-consuming steps of calculating the orientation settings for the model of the aircraft in roll, pitch and yaw for the first phot;ographic camera in the first photographic step as well a calculating appropriate image range settings for the second photographic camera in the second photographic step are voided by the use of apparatus according to the fifth aspect of the invention, and that use of such apparatus is particularly advantageous when a wide variety of target aircraft flight profiles are required on the final film.
Preferably, the computing apparatus is such as to provide the first script with a new setting only in response to a change in roll, pitch or yaw exceeding a predetermined minimum value and the second script with a new setting only in response to a change in slant range exceedi.ng a predetermined minimum value.
1~3~
Some embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:-Eig. 1 is a schematic perspective view of a modelaircraft mounted on a gimballed support structure for use in the production of cinematograph film according to the invention, and Fig. 2 is a flow chart setti.ng out the steps in qenerating operator scri.pts for use in the production of cinematograph film according to the invention.
Referring first to Fig. 1, a model 11 of an aircraft whose fliyht in a predetermined flight profile is to be represented on a cinematograph film is tail mounted on an output shaft 12 of a gearbox 13, which is in turn mounte-l by means of an angle bar 14 on the output shaft of a further gearbox 15 likewise mounted by an angle bar 16 on the output shaft of a further gearbox 17 Lixedly mounted on a base plate 18. Each of the gearboxes 13,15 and 17 have input shafts which can be 3~7~6~
turned by hand knobs 19,20 and 21 to cause rotation of their output shafts. As wil] he seen from Fig. 1, the angular disposition of the model 11 about its roll axis can be changed by rotation of the output shaft 12 under the control of the control knob 19. The angular disposition of the model 11 about its pitch axis can likewise be changed by rotation of the output shaft of the gearbox 15 under the control of the control knob 20. The angular disposition of the model 11 about its yaw axis can be changed by rotation of the output shaft of the gearbox 17 under the control of the knob 21.
The gear ratio of the pitch controlling gearbox 15 is 100:1 in order to provide sufficient frictional torque to prevent rotation due to gravity. The roll and yaw controlling gearboxes 13 and 17 are arranged to have ratios of 10:1. The gearbox 17 may if necessary be fitted with an extension arm and a remote control knob to facilitate its operation. A 0 - 360 direct reading analogue scale is fitted to the output shaft of each gearbox.
A first camera (not shown), which may be a single lens reflex camera, is mounted on a camera mount in a position in which it views head on the model 11 as shown in Fig. 1. The camera is specially modified to provide for the accurate positioning of each frame of the film in relation to the camera aperture. In particular, film frame registration pins are located on the hinged rear coverplate of the camera and are movable toward the film plate over the camera aperture.
The ends of the pins are tapered so that they easily enter sprocket holes in the film at the camera aperture ~Z3~2~
and when extended fully through the sprocket holes align each frame of the film at exactly the same position for exposure, with the film frame positioned such that the edges of the frame and centre conform exactly to those of the camera aperture.
Successive frames are exposed with the model 11 at predetermined roll, pitch and yaw attitudes. A further model identical to the model 11 shown in Fig. 1 is then nose-mounted on to the output shaft 12 of the gearbox 13 and further film frames exposed with the nose-mounted model at predetermined roll, pitch and yaw attitudes. The exposed film is then processed and each frame mounted in slides, which carry their own registration pins enabling the sprocket holes of each film frame to be aligned exactly in the same position in the slide as it was positioned in the camera.
The images carried by the slide mounted frames are next copies on to 16mm cinematograph film. For this purpose, a second camera, in the form of a 16mm pin-registered precision rostrum camera, is mounted vertically above a slide support structure for supporting the slide to be copied. The slides are copied in turn on to the 16mm film in the required sequence and at each copying operation the height of the rostrum camera above the slide is so adjusted that the size of the copied image takes account of the range of the aircraft at that position in its flight profile, as determined by the slide being copied.
The rostrum camera is used to produce a 16mm film strip master for each of several aircraft flight profiles.
~L;23~6~L
the several film strip masters are then processed and edited in a film processing laboratory.
It will be appreciated that the production of cinematograph film carrying a variety of target aircraft flight profiles is time-consuming and that there is a need for reducing the repetitive work to be carried out by the personnel engaged in the various steps in the photographic process. To this end, there is included in accordance with the second aspect of the invention the further step of reducing the number of frames copied onto the 16mm film by omitting one or more frames which would succeed a predetermined frame and which display images whose orientation and size do not differ from those of the predetermined frame by more than a predetermined amount and arranging for the film to be provided with.recorded information as to omitted frames so that the cinematograph projector used to project the images from the cinematograph film can be controlled to hold the predetermined frame for a projection time equivalent to that interval which would be required for the projection also of the omitted frames.
It would of course be a simple operation repeatedly to copy on to the frames 16mm film the predetermined frame of the slide from which the succeeding frames vary little. It will, however, be appreciated that although the film production personnel's time is saved, the final length of film carrying the aircraft flight profile remains the same and no reduction is made in the time required to access any of the several flight profiles carried on the final film to be projected. By omitting what would otherwise be repetitive frames the length of the film taken for the particular flight profile is reduced and the time for accessing any one of the profiles on the film where that particular flight profile needs to be traversed is also reduced.
It will furthermore be appreciated that although the production of cinematograph film by the methods hereinbefore specifically described is far less expensive than a method of production in which actual aircraft flights are photographed it is nevertheless time-consuming for the film production personnel and therefore still costly. As a result of this, the variety of target aircraft flight profiles is limited and usually the flight profiles of only one aircraft produced.
Clearly, the step of calculating the required roll, pitch and yaw orientation settings of the model for the roll pitch and yaw gearboxes 13,15 and 17 in the production of the slides is time-consuming.
Furthermore, calculation of appropriate range settings for use with the second camera is also time-consuming.
Accordingly, scripts for the operator to use in setting the gearboxes 13,15 and 17 and the position of the second camera are produced by computing apparatus now to be described with reference to Fig. 2.
Referring now to Fig. 2, there are four stages involved in the production of the film. The first stage involves the running of a flight profile program, the second stage involves the running of a film production program which generates the shooting scripts for the ~LZ3~L26~
profile, the third stage is the photographic process which is carried out as hereinbefore described and the fourth stage is the collation of the several flight profile masters into a single length of cinematograph film, followed by coding of the film.
The flight profile program is run to create a data file containing the aircraft's position and orientation, with respect to the earth's axis, at fixed intervals of time during its flight. This program is capable of representing all the basic flight profiles of a modern attack/offensive support aircraft. The input to the program is flight path data containing the aircraft's start position and subsequent manoeuvres during its flight.
The film production program is run to generate the shooting scripts for the profile. There are three sections to this program as follows:-20tl) A first section calculates the aircraft's slant range and aircraft orientation along a line of sight (LOS) at fixed time intervals along the flight path.
The output from this is time, slant range, aircraft LOS
heading, aircraft LOS pitch and aircraft l.OS roll.
T~RGET_IMAGE PRESENTATION SYSTEM
BACKGROUND OF THE INVENTION
Field of the Invention the present invention relates to a target image presentation system in which the image of a target is provided on a cinematograph film and is projected from the film on to a screen by a cinematograph projector.
Description of the Prior Art In a target acquisition training system which has been proposed, a target image presentation system displays images of a target aircraft on the interior surface of a part-spherical dome in such a manner as to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile within a air space surrounding the observer. The target image presentation system includes a cinematograph film bearing on successive frames of the film target image corresponding to those which would be viewed by a ground observer within the dome at successive fixed time intervals during the flight of the aircraft in the predetermined flight profile, a cinematograph projector which projects images from the film in an image carrying beam and an image beam deflection assembly which directs the image carrying beam to positions on the dome corresponding to the positions of the aircraft flying the predetermined flight profile.
In the target acquisition training system hereinbefore described, the cinematograph film used has been produced using a cinematoyraph camera directed via a mirror on to an aircraft flying a predetermined flight profile to be represented and simultaneously recording signals representing the azimuth and elevation of the ,~,..~0,' L26~
aircraft during the shooting of the film. The film is then processed to produce a master from which one or more copies are made. The copy is then used in the cinematograph projector in the dome and means are provided for moving the image beam deflection assembly in accordance with the recorded azimuth and elevation signals and arranging to synchronise the image beam deflection with the projection of images from the film so as to produce on the dome a moving image simulating the flight of the aircraft.
Description of the Prior Art The projection of target aircraft images on to the surface of the dome in the manner described has been regarded as satisfactory for the development of tracking skills by trainee anti-aircraft gunners, but the production of the films has been costly and as a result confined to a few simple aircraft flight profiles. It is an object of the present invention to provide a cost effective method of producing a cinematograph film which meets the above-mentioned need.
It is a further object of the present invention to provide a cinematograph film produced by the method and a target image presentation system including a cinematograph film so produced.
It is yet another object of the present invention to provide apparatus for producing a cinematograph film by the method.
According to a first aspect of the present invention there is provided a method of producing a cinematograph ~L~3~Z'~
film for use in an image presentation system in which images are projected on to a screen to provide for an observer viewing the screen a visual representation of an object moving in a predetermined path relative to the observer, the method comprising the steps of displaying a model of the object, photographirlg on to a first photographic film images of the model in a manner such that different frames of the film display images of the object at different orientationC~ photographing on to successive frames of a second photographic film images carried on frames of the first film to produce a sequence ox images on the second film having orientations corresponding to those of the object as would be viewed by an observer during movement of the object in the predetermined path relative to the observer while adjusting the sizes of the images on the frames of the second film to simulate variations in the range of the object from the observer.
Preferably, the cinematograph film is intended for use in an image presentation system in which the images of a target aircraft are projected on to the interior surface of a part-spherical dome to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile within an air space surrounding the observer, and in which cinematograph projection means projects images from the cinematograph film in an image-carrying beam and directs the image carrying beam to positions on the dome corresponding to the positions of the aircraft flying the predetermined flight profile. The images produced on the second film then have line of sight orientations corresponding to those which would be ~3~26~
viewed hy an observer during movement of the aircraft flying the predetermined flight profile. The cinematograph projection means preferably comprises a stationary projector for projecting the image carrying beam and an image beam deflection assembly for directing the beam on to the dome.
In the embodiment of the invention hereinafter to be described the images of the model aircraft are photographed on to the first film in a sequence in which successive images have orientations corresponding to those successively taken up during movement of the aircraft in the predetermined flight profile and are transferred to the second film in the same sequence, while adjusting the sizes of the images to simulate variations in the range of the aircraft from the observer. It will however be appreciated that in some circumstances it may be considered preferable to produce a library of slides in which the images have orientations whi.ch could be selected for any one of a large plurality of different target flight profiles, selecting from the library those slides having images with orientations appropriate for a particular flight profile and photographing on to the second film the images on the selected slides in a sequence required for that flight profile.
The model is preferably a reduced scale model of the aircraft and is supported on a gimballed model support structure for angular displacement about its pitch, yaw and roll axes and the images of the model are photographed on to the first film by a photographic ~3~Z6~
camera 1ocated at a fixed distance from the model support structure.
In a preferred embodiment of the invention, the images carried by the frames of the first film are photographed on to the frames of the second film by individually mounting each frame in a slide; placing each slide in turn in a fixed slide support structure and photographing the image carrying frame of each slide on to the second film using a second photographic camera, while adjusting the second camera to vary the size of the image transferred on to the second film.
Preferably, the size of the image transferred on to the second film is varied by varying the range of the second camera from the slide support structure.
While a considerable reduction in the cost of film production can be made by photographing a model of the aircrafl: iTI place of an actual aircraft in accordance with the first aspect o the invention, the production cf the film in this way needs to be carried out to exacting standards and is very time-consumin~. As a result, one film is produced bearing several target flight profiles of one aircraft type and copies of this film made and supplied with the target acquisition training systems when sold. The systems are however widely used throughout the world and a film suitable for use in training personnel of one armed force who would recognise the aircraft as an enemy aircraft would be unsuitable for use by personnel of another armed force who would recognise the aircraft type as friendly. Furthermore, training in aircraft recognition can only be advanced by providing target ~z~3L2i~
flight profiles of aircraft of many different types and providing the facility of selecting a sequence of profiles in which the aircraft type changes from one profile to the next.
The use of sound effects simulating aircraft noise and anti-aircraft gun-fire and the use of actual weapons in the dome modified to simulate firing have produced a realistic environment for a gunner, but it has been found that it falls far short of an environment likely to be experienced in a real multiple aircraft attack in which aircraft of different types are overflying the air space in different directions in rapid succession and executing different manoeuvres and where a choice needs to be made by the gunner as to which aircraft to engage.
While several target aircraft flight profiles can be included on one cinematograph film, there is the disadvantage that the order in which the profiles are projected is fixed, unless provision is made for selectively accessing the target flight profiles on the film. To reduce the average access time it has been proposed to employ a continuous motion projector incorporating a holoscope rotating prism. The projector film capacity can be made of the order of 720 metres (2,400 feet) providing a maximum running time of 60 minutes at 25 frames per second if target flight profiles are projected in consecutive order from the film. The maximum access time from the end of the first profile to the start ox the last is six minutes at lO times normal running speed, with normal average access time between selected target flight profiles ~;~3~6~
which are non-consecutive in the region of 30 to 60 seconds.
Chile the use of a continuous motion film projector as described makes it possible to vary the sequence in which the target flight profiles are projected, it has been found that the access time between flight profiles in a selected sequence is frequently too long and does not adequately represent circumstances in a real attack situation.
It will be apparent that there is a need for a target flight profile film which can be produced readily and at low cost, which bears a multiplicity of target flight profiles of wide variety and in which alternative sequences of the profiles can be accessed from the film without unacceptable access times.
According to a second aspect of the invention, there is provided a method of producing cinematograph film according to the first aspect of the invention and including the step of reducing on the second film the number of frames carrying images representing the predetermined target flight profile by omitting one or more frames which would succeed a predetermined frame in the target flight profile and which would carry images whose orientations do not deviate from that of the image of the predetermined frame by more than a predetermined amount and providing stored information as to omitted frames, whereby the cinematograph ~L23126~ 1 projection means can be control]ed to hold the predetermined frame for a projection time equivalent to that interval which would be required for the projection also of the omitted frames.
Additionally or alternatively the method according to the second aspect of the invention includes the step of reducing on the second film the number of frames carrying images representing the target flight profile by omitting one or more frames which would succeed a predetermined frame in the target flight profile and which would carry images whose sizes do not deviate from that of the image of the predetermined frame by more than a predetermined amount and providing stored information as to omitted frames, whereby the cinematograph projection means can be controlled to hold the predetermined frame for a projection time equivalent to that interval which would be required for the projection also of the omitted frames.
By introducing the step of omitting one or more frames from the film, it has been found that the length of the target flight profile on the film can for many profiles be markedly reduced without any apparent loss of image recognition by a gunner tracking the target image when projected as hereinbefore described.
According to a third aspect of the present invention there is provided a cinematograph film produced by the method accordirlg to the first or second aspect of the invention.
~ccordlng to a fourth aspect of the invention there is provided t:arget image presentation system in which the images of a target aircraft are projected on to the interior surface of a part-spherical dome to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile withi.n an air space surrounding the observer, and in which cinematograph projection means projects images from a cinematograph film in an image-carrying beam and directs the image carrying beam to positions on the dome corresponding to the positions of the aircraft flying the predetermined flight profile, a cinematograph film produced by a method according to the second aspect of the invention, and means responsive to the stored information as to omitted frames to control the advancement of the cinematograph film through tlle projection means whereby the image of the predetermined film frame is projected for an extended period to compensate for the omitted frames in the film.
; 25 according to a fifth aspect of the present invention there is provided apparatus for producing a cinematograph film by the method according to the first aspect of the invention for use in an image presentation system in which the images of a target aircraft are projected on to the interior surface of a part-spherical dome to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile within an air space ..~ .,~
69 f ;3 ~L23~L26a~
surroundiny the ohserver, and in which cinematograph projection means projects images from a cinematograph film i.n an i.mage-carrying beam and directs the image ; carrying beam to positions on the dome corresponding to the posi.tions of the aircraEt flying the predetermined flight profile, the apparatus comprising a model support structure for supporting the model $or angular displacement about its pitch, yaw and roll axes, means for angularly displacing the model on the structure about its pitch, yaw and roll axes, a first photographic camera mounted at a fixed range from the model support structure for photographing on to a first photographic film images of the model in a manner such that different frames of the film display images of the ]5 model at different orientations, a second photographic camera for photographing on to successive frames of a second photographic film the images carried on frames of the first film to produce a sequence of images on the second fi.lm having line of sight orientations ; 2~ correspotlding to those which would be viewed by an observer during movement of the aircraft flying the predetermined profi.le, the second camera being so mounted as to include provision for adjusting the range of the second camera from the second film, wherehy the sizes of the i.mages on the frames of the second film can be vari.ed to simulate variations in the slant range of the aircraft from the observer, and computing apparatus responsive firstly to input flight path data to gellerate and store in a first data file data representing the aircraft's position and orientation with respect to earth coordinates at successive time intervals during the flight of the aircraft in the flight profile, secondly to data in the first data file ,, , . I, "I.
~23~L2~i~
to generate and store in a second data file data representing the aircraft's line of sight orientation and slant range with respect to a predetermined datum position at the successive time intervals and thirdly to data in the second data file to generate a first script to be utilised by an operator of the first photographic camera and which provides a sequence of pitch, roll and yaw settings for the model applicable t.o successive time intervals in the profile and to generate a second script to be utilised by an operator of the second photographic camera and which provides a sequence of settings for the ranqe of the second photographic camera from the frame of the first film to he photographed applicable to the successive time intervals in the profile.
It will be appreciated that the time-consuming steps of calculating the orientation settings for the model of the aircraft in roll, pitch and yaw for the first phot;ographic camera in the first photographic step as well a calculating appropriate image range settings for the second photographic camera in the second photographic step are voided by the use of apparatus according to the fifth aspect of the invention, and that use of such apparatus is particularly advantageous when a wide variety of target aircraft flight profiles are required on the final film.
Preferably, the computing apparatus is such as to provide the first script with a new setting only in response to a change in roll, pitch or yaw exceeding a predetermined minimum value and the second script with a new setting only in response to a change in slant range exceedi.ng a predetermined minimum value.
1~3~
Some embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:-Eig. 1 is a schematic perspective view of a modelaircraft mounted on a gimballed support structure for use in the production of cinematograph film according to the invention, and Fig. 2 is a flow chart setti.ng out the steps in qenerating operator scri.pts for use in the production of cinematograph film according to the invention.
Referring first to Fig. 1, a model 11 of an aircraft whose fliyht in a predetermined flight profile is to be represented on a cinematograph film is tail mounted on an output shaft 12 of a gearbox 13, which is in turn mounte-l by means of an angle bar 14 on the output shaft of a further gearbox 15 likewise mounted by an angle bar 16 on the output shaft of a further gearbox 17 Lixedly mounted on a base plate 18. Each of the gearboxes 13,15 and 17 have input shafts which can be 3~7~6~
turned by hand knobs 19,20 and 21 to cause rotation of their output shafts. As wil] he seen from Fig. 1, the angular disposition of the model 11 about its roll axis can be changed by rotation of the output shaft 12 under the control of the control knob 19. The angular disposition of the model 11 about its pitch axis can likewise be changed by rotation of the output shaft of the gearbox 15 under the control of the control knob 20. The angular disposition of the model 11 about its yaw axis can be changed by rotation of the output shaft of the gearbox 17 under the control of the knob 21.
The gear ratio of the pitch controlling gearbox 15 is 100:1 in order to provide sufficient frictional torque to prevent rotation due to gravity. The roll and yaw controlling gearboxes 13 and 17 are arranged to have ratios of 10:1. The gearbox 17 may if necessary be fitted with an extension arm and a remote control knob to facilitate its operation. A 0 - 360 direct reading analogue scale is fitted to the output shaft of each gearbox.
A first camera (not shown), which may be a single lens reflex camera, is mounted on a camera mount in a position in which it views head on the model 11 as shown in Fig. 1. The camera is specially modified to provide for the accurate positioning of each frame of the film in relation to the camera aperture. In particular, film frame registration pins are located on the hinged rear coverplate of the camera and are movable toward the film plate over the camera aperture.
The ends of the pins are tapered so that they easily enter sprocket holes in the film at the camera aperture ~Z3~2~
and when extended fully through the sprocket holes align each frame of the film at exactly the same position for exposure, with the film frame positioned such that the edges of the frame and centre conform exactly to those of the camera aperture.
Successive frames are exposed with the model 11 at predetermined roll, pitch and yaw attitudes. A further model identical to the model 11 shown in Fig. 1 is then nose-mounted on to the output shaft 12 of the gearbox 13 and further film frames exposed with the nose-mounted model at predetermined roll, pitch and yaw attitudes. The exposed film is then processed and each frame mounted in slides, which carry their own registration pins enabling the sprocket holes of each film frame to be aligned exactly in the same position in the slide as it was positioned in the camera.
The images carried by the slide mounted frames are next copies on to 16mm cinematograph film. For this purpose, a second camera, in the form of a 16mm pin-registered precision rostrum camera, is mounted vertically above a slide support structure for supporting the slide to be copied. The slides are copied in turn on to the 16mm film in the required sequence and at each copying operation the height of the rostrum camera above the slide is so adjusted that the size of the copied image takes account of the range of the aircraft at that position in its flight profile, as determined by the slide being copied.
The rostrum camera is used to produce a 16mm film strip master for each of several aircraft flight profiles.
~L;23~6~L
the several film strip masters are then processed and edited in a film processing laboratory.
It will be appreciated that the production of cinematograph film carrying a variety of target aircraft flight profiles is time-consuming and that there is a need for reducing the repetitive work to be carried out by the personnel engaged in the various steps in the photographic process. To this end, there is included in accordance with the second aspect of the invention the further step of reducing the number of frames copied onto the 16mm film by omitting one or more frames which would succeed a predetermined frame and which display images whose orientation and size do not differ from those of the predetermined frame by more than a predetermined amount and arranging for the film to be provided with.recorded information as to omitted frames so that the cinematograph projector used to project the images from the cinematograph film can be controlled to hold the predetermined frame for a projection time equivalent to that interval which would be required for the projection also of the omitted frames.
It would of course be a simple operation repeatedly to copy on to the frames 16mm film the predetermined frame of the slide from which the succeeding frames vary little. It will, however, be appreciated that although the film production personnel's time is saved, the final length of film carrying the aircraft flight profile remains the same and no reduction is made in the time required to access any of the several flight profiles carried on the final film to be projected. By omitting what would otherwise be repetitive frames the length of the film taken for the particular flight profile is reduced and the time for accessing any one of the profiles on the film where that particular flight profile needs to be traversed is also reduced.
It will furthermore be appreciated that although the production of cinematograph film by the methods hereinbefore specifically described is far less expensive than a method of production in which actual aircraft flights are photographed it is nevertheless time-consuming for the film production personnel and therefore still costly. As a result of this, the variety of target aircraft flight profiles is limited and usually the flight profiles of only one aircraft produced.
Clearly, the step of calculating the required roll, pitch and yaw orientation settings of the model for the roll pitch and yaw gearboxes 13,15 and 17 in the production of the slides is time-consuming.
Furthermore, calculation of appropriate range settings for use with the second camera is also time-consuming.
Accordingly, scripts for the operator to use in setting the gearboxes 13,15 and 17 and the position of the second camera are produced by computing apparatus now to be described with reference to Fig. 2.
Referring now to Fig. 2, there are four stages involved in the production of the film. The first stage involves the running of a flight profile program, the second stage involves the running of a film production program which generates the shooting scripts for the ~LZ3~L26~
profile, the third stage is the photographic process which is carried out as hereinbefore described and the fourth stage is the collation of the several flight profile masters into a single length of cinematograph film, followed by coding of the film.
The flight profile program is run to create a data file containing the aircraft's position and orientation, with respect to the earth's axis, at fixed intervals of time during its flight. This program is capable of representing all the basic flight profiles of a modern attack/offensive support aircraft. The input to the program is flight path data containing the aircraft's start position and subsequent manoeuvres during its flight.
The film production program is run to generate the shooting scripts for the profile. There are three sections to this program as follows:-20tl) A first section calculates the aircraft's slant range and aircraft orientation along a line of sight (LOS) at fixed time intervals along the flight path.
The output from this is time, slant range, aircraft LOS
heading, aircraft LOS pitch and aircraft l.OS roll.
(2) A second section outputs the script for the opPrator of the first camera to use with the model orientation assembly shown in Fig. 1. The program contains an algorithm for detecting when the model's orientation has changed sufficiently to justify a new slide to be produced.
~:3~LXG~
~:3~LXG~
(3) third section outputs the script for the 16mm camera operator. This program contains an algorithm for detecting when the aircraft's slant range has changed sufficiently to justify a change in -the size of the image to be transferred from the slide to the 16mm cinematograph film frame.
Two identical models of the target aircraft are employed. One model is tail~mounted as illustrated in Fig. 1 of the drawings while the other is nose-mounted and the computing apparatus is programmed to select the appropriate model to be photographed by the irst camera in the production of the slides.
The final cinematograph film bearing the flight profiles is provided with a black continuous optical sound track which extends over the whole of that portion of the film which will be projected. This enables the projector to detect the zero frame position and the starting point for a frame counter and to stop the film and prevent it running off the spools.
Two identical models of the target aircraft are employed. One model is tail~mounted as illustrated in Fig. 1 of the drawings while the other is nose-mounted and the computing apparatus is programmed to select the appropriate model to be photographed by the irst camera in the production of the slides.
The final cinematograph film bearing the flight profiles is provided with a black continuous optical sound track which extends over the whole of that portion of the film which will be projected. This enables the projector to detect the zero frame position and the starting point for a frame counter and to stop the film and prevent it running off the spools.
Claims (12)
1. A method of producing a cinematograph film for use in an image presentation system in which images are projected on to a screen to provide for an observer viewing the screen a visual representation of an object moving in a predetermined path relative to the observer, the method comprising the steps of displaying a model of the object, photographing on to a first photographic film images of the model in a manner such that different frames of the film display images of the object at different orientations, photographing on to successive frames of a second photographic film the images carried on frames of the first film to produce a sequence of images on the second film having orientations corresponding to those of the object as would be viewed by an observer during movement of the object in the predetermined path relative to the observer while adjusting the sizes of the images on the frames of the second film to simulate variations in the range of the object from the observer.
2. A method according to claim 1 for producing a cinematograph film for use in an image presentation system in which the images of a target aircraft are projected on to the interior surface of a part-spherical dome to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile within an air space surrounding the observer, and in which cinematograph projection means projects images from the cinematograph film in an image-carrying beam and directs the image carrying beam to positions on the dome corresponding to the positions of the aircraft flying the predetermined flight profile and wherein the images produced on the second film have line of sight orientations corresponding to those which would be viewed by an observer during movement of the aircraft flying the predetermined flight profile.
3. A method according to claim 2, wherein the model is a reduced scale model of the aircraft and is supported on a gimballed model support structure for angular displacement about its pitch, yaw and roll axes.
4. A method according to claim 3, wherein the images of the model are photographed on to the first film by a photographic camera located at a fixed distance from the model support structure.
5. A method according to claim 4, wherein the images carried by the frames of the first film are photographed on to the frames of the second film by individually mounting each frame in a slide, placing each slide in turn in a fixed slide support structure and photographing the image carrying frame of each slide on to the second film using a second photographic camera, while adjusting the second camera to vary the size of the image transferred on to the second film.
6. A method according to claim 5, wherein the size of the image transferred on to the second film is varied by varying the range of the second camera from the slide support structure.
7. A method according to claim 2 including the step of reducing on the second film the number of frames carrying images representing the predetermined target flight profile by omitting one or more frames which would succeed a predetermined frame in the target flight profile and which would carry images whose orientations do not deviate from that of the image of the predetermined frame by more than a predetermined amount and providing stored information as to omitted frames, whereby the cinematograph projection means can be controlled to hold the predetermined frame for a projection time equivalent to that interval which would be required for the projection also of the omitted frames.
8. A method according to claim 2 including the step of reducing on the second film the number of frames carrying images representing the target flight profile by omitting one or more frames which would succeed a predetermined frame in the target flight profile and which would carry images whose sizes do not deviate from that of the image of the predetermined frame by more than a predetermined amount and providing stored information as to omitted frames, whereby the cinematograph projection means can be controlled to hold the predetermined frame for a projection time equivalent to that interval which would be required for the pro-jection also of the omitted frames.
9. A target image presentation system in which the images of a target aircraft are projected on to the interior surface of a part-spherical dome to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile within an air space surrounding the observer, the system comprising a cinematograph film produced by a method according to claim 2 and a cinematograph projection means arranged to project images from the cinematograph film in an image carrying beam, and to direct the image carrying beam to positions on the dome corre-sponding to the positions of the aircraft flying the predetermined flight profile.
10. A target acquisition training system including a target image presentation system in which the images of a target aircraft are projected on to the interior surface of a part-spherical dome to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile within an air space surrounding the observer, and in which cinematograph projec-tion means is arranged to project images from a cinematograph film in an image carrying beam and to direct the image carrying beam to positions on the dome corresponding to the positions of the air-craft flying the predetermined flight profile, a cinematograph film produced by a method according to claim 7 or 8, and means responsive to the stored information as to omitted frames to control the advancement of the cinematograph film through the projection means whereby the image of the predetermined film frame is projected for an extended period to compensate for the omitted frames in the film.
11. Apparatus for producing, by the method according to claim 1, a cinematograph film for use in an image presentation system in which the images of a target aircraft are projected on to the interior surface of a part-spherical dome to provide for an observer within the dome a visual representation of an aircraft flying a predetermined flight profile within an air space surrounding the observer, and in which cinematograph projection means projects images from a cinematograph film in an image-carrying beam and directs the image carrying beam to positions on the dome corresponding to the positions of the aircraft flying the predetermined flight profile, the apparatus comprising a model support structure for supporting the model for angular displacement about its pitch, yaw and roll axes, means for angularly displacing the model on the structure about its pitch, yaw and roll axes, a first photographic camera mounted at a fixed range from the model support structure for photographing on to a first photographic film images of the model in a manner such that different frames of the film display images of the model at different orientations, a second photographic camera for photographing on to successive frames of a second photographic film the images carried on frames of the first film to produce a sequence of images on the second film having line of sight orientations corresponding to those which would be viewed by an observer during movement of the aircraft flying the predetermined profile, the second camera being so mounted as to include provision for adjusting the range of the second camera from the second film, whereby the sizes of the images on the frames of the second film can be varied to simulate variations in the slant range of the aircraft from the observer, and computing apparatus responsive firstly to input flight path data to generate and store in a first data file data representing the aircraft's position and orientation with respect to earth coordinates at successive time intervals during the flight of the aircraft in the flight profile, secondly to data in the first data file to generate and store in a second data file data representing the aircraft's line of sight orientation and slant range with respect to a predetermined datum position at the successive time intervals and thirdly to data in the second data file to generate a first script to be utilised by an operator of the first photographic camera and which provides a sequence of pitch, roll and yaw settings for the model applicable to successive time intervals in the profile and to generate a second script to be utilised by an operator of the second photographic camera and which provides a sequence of settings for the range of the second photographic camera from the frame of the first film to be photographed applicable to the successive time intervals in the profile.
12. Apparatus according to claim 11, wherein the computing apparatus is such as to provide the first script with a new setting only in response to a change in roll, pitch or yaw exceeding a predetermined minimum value and to provide the second script with a new setting only in response to a change in slant range exceeding a predetermined minimum value.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8313475 | 1983-05-16 | ||
| GB8313475 | 1983-05-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1231264A true CA1231264A (en) | 1988-01-12 |
Family
ID=10542821
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000453987A Expired CA1231264A (en) | 1983-05-16 | 1984-05-10 | Target image presentation system |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1231264A (en) |
| DE (1) | DE3418236A1 (en) |
| FR (1) | FR2546322B1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4702699A (en) * | 1984-03-02 | 1987-10-27 | Gq Defence Equipment Limited | Target image presentation system |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB691214A (en) * | 1950-11-09 | 1953-05-06 | County Commercial Cars Sales L | Improvements in or relating to optical projection systems |
| US3588237A (en) * | 1969-02-05 | 1971-06-28 | Us Navy | Moving target simulator |
| GB2003103B (en) * | 1977-08-27 | 1982-01-06 | British Aircraft Corp Ltd | Simulators |
-
1984
- 1984-05-10 CA CA000453987A patent/CA1231264A/en not_active Expired
- 1984-05-16 DE DE19843418236 patent/DE3418236A1/en not_active Withdrawn
- 1984-05-16 FR FR8407594A patent/FR2546322B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2546322A1 (en) | 1984-11-23 |
| DE3418236A1 (en) | 1984-12-06 |
| FR2546322B1 (en) | 1989-01-06 |
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