AU687824B2

AU687824B2 - Maw flight line test set

Info

Publication number: AU687824B2
Application number: AU69915/94A
Authority: AU
Inventors: Shane Anthony Brunker; Kenneth John Grant
Original assignee: Commonwealth of Australia
Current assignee: Commonwealth of Australia
Priority date: 1993-06-25
Filing date: 1994-06-24
Publication date: 1998-03-05
Anticipated expiration: 2014-06-24
Also published as: AU6991594A

Description

WO 95/00813 PCT/AU94/00347 1 "MAW FLIGHT LINE TEST SET" This invention relates to an Ultra Violet (UV) Light Source adapted to mimic a plurality of offensive airborne weapons configurable to provide a device for testing threat warning equipment carried by various craft.

BACKGROUND

One example of an offensive airborne weapon is a rocket propelled missile. For each type of missile there exists a unique spatial and temporal spectral emission and of the wide range of their spectral emissions the UV segment is readily and optimally detected remote of the missile.

Advantageously, equipment has been developed to detect the presence and approach of various offensive airborne weapons and in particular missile approach warning equipment has been fitted to various craft predominantly fixed and rotary winged craft. Typically, a missile approach warning device comprises a sensor, interpretive electronics and pilot warning means. The sensor is designed to detect all or predetermined portions of the UV spectrum. The interpretive electronics of the device is adapted to process the signals from the sensor and determine whether those signals are representative of a missile's spectral emission whereupon a suitable warning is indicated to the aircraft's pilot.

The interpretive electronics ensures that the received signals fit one of a predetermined range of missile emission profiles before initiating any warning procedure. To fulfil this need the sensor signals which result from the proximity of various missiles have been determined and characterised by spectral and temporal parameters, which are stored in the equipment and referred to as a template of a missile emission profile and a group of such templates is referred to as a library.

pt I I I L- WO 95/00813 PCT/AU94/00347 2 To the present time, the technique used to test a missile approach warning device which is fitted to various craft, has comprised, directing a broad spectrum UV light source towards the device and spinning a fan at an optimum rate so as to break the UV light beam in such a manner as to mimic at least one of the variety of expected UV spectral emission profiles.

Such a technique obviously lacks consistency, repeatability and fails to test the full range of the missile approach warning device's sensor and template library.

It is an aspect of this invention to overcome the abovementioned problems and provide a portable device to test in situ missile approach warning apparatus.

BRIEF DESCRIPTION OF THE INVENTION In its broadest aspect the invention is an ultra violet light emission apparatus comprising an ultra violet light source, shutter means operable to pass said ultra violet light, and control means to operate said shutter means whereby the ultra violet light temporal spectral emission profile of said apparatus mimics that of an offensive airborne weapon.

In a further aspect of the invention the ultra violet light emission apparatus further comprises modulation means adapted to modulate said light source whereby the emission profile of said apparatus mimics that of an offensive airborne weapon.

In yet a further aspect of the invention the ultra violet light emission apparatus further comprises synchronisation means adapted to synchronise with the control

MMO

WO 95/00813 PCT/AU94/00347 3 means the operation of said shutter means with said modulation means.

Yet a further aspect of the invention comprises a spectral filter means positioned so as to pass from said apparatus a predetermined wavelength portion of the ultra violet spectrum.

An additional aspect of the invention comprises a storage means adapted to contain data representative of a plurality of shutter control characteristics and a plurality of modulation characteristics which are adapted to be combined to control said control means, said modulation means and/or said synchronisation means, to mimic the temporal spectral emission profile of an offensive airborne weapon.

A further additional aspect of the invention comprises a hand held body within which said ultra violet light emission apparatus is contained which in use is adapted to allow an emission profile created by the apparatus to be directed towards a craft housing the on offensive airborne weapon detector device.

A preferred embodiment of the invention will now be described but it will be understood that the invention need not be limited to any one or combination of the following features.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings, wherein: Fig 1 depicts a functional block diagram of an airborne missile approach warning device test apparatus, WO 95/00813 PCT/AU94/00347 4 Fig 2 depicts a hand held embodiment of the test apparatus, Fig 3 depicts one temporal profile of a possible missile emission profile provided by the test apparatus, and Fig 4 depicts a further temporal profile of a possible threat emission profile provided by the test apparatus.

DETAILED DESCRIPTION OF THE INVENTION To simplify the description of this embodiment of the invention the use of like numerals will identify like elements in all the figures used to describe the embodiment.

Figs 1 and 2 depict various elements of an ultra violet light source configured as an aircraft borne missile approach warning equipment test apparatus.

An ultra violet light source 10, ini this embodiment, is a quartz halogen lamp chosen for its ability to provide a spectral emission at least over the required UV band and creating at the craft borne warning device sensor (not shown) the required irradiance. A power supply 11 provides a power source to the light source 10 and the control circuit 12.

Typically, the power supply is capable of supplying approximately 1 Amp regulated at 6 volts d.c. to the components of the apparatus.

Control circuit 12 is designed to control the supply of power to the light source 10 such that the light source output can be modulated by, in this embodiment, switching the power to the source on and off at a desired rate and duty cycle. Furthermore, the source may be modulated over time by voltage variations applied to the light source so as to vary the peak irradiance received by the sensor of the warning device. The modulation of the light source output mimics the

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L_ WO 95/00813 PCT/AU94/00347 temporal profile of the ultra violet light source of an offensive weapon. However, this portion of the template radiated by the test apparatus is only required when the shutter means 17 is fully open.

The test apparatus operating switch 13 is used to initiate and cease the operation of the apparatus. In this embodiment a normally open momentary contact switch is used to apply power to the light source 10 via an analogue charging and trigger circuit 14.

This is one aspect of the temporal profile of the light source which is controlled by modulating the power supplied to the light source. One of two or more template parameters are stored in the template storage circuit 15. Switch 16 is one of many ways to select which of the templates stored in EPROM/S 15a or 15b are to be used to create the modulation signal applied to the light source 10 as well as used to control the other parameters of the desired template.

The leading and trailing edges of two different emission templates as are depicted in Figs 3 and i. These edges have been found to be important when creating an acceptable missile emission profile. Controlling the opening rate and the closing rate of the shutter means 17 is one way to provide the required rise tr and fall tf times of the emission template. Controlling the period of time the shutter is open provides the required time to emit a required template exposure of ultra violet light towards the sensor of the warning device so as to mimic one of the many missile templates designed to be detected by the warning device.

The shutter means 17 of this embodiment is not unlike the circular aperture shutter of a camera and may be operated by mechanical or electronic means, however, in this embodiment it is of the electronic type which is provided a control pulse from the trigger circuit 14 to open and a WO 95/00813 PCT/AU94100347 6 reverse polarity pulse to close the shutter. The template storage circuit 15 monitors the opening and closing of the shutter means 17 so that the various templates can be used while the shutter is open.

3 depicts one example of an emission template with effective irradiance shown along the vertical axis and time along the horizontal axis, likewise for Fig 4.

The respective rise times tr and the fall times tf are the same in each example while the difference between the templates is provided by the type of modulation imposed upon the light source during the tO period. However, the rise and fall times of different templates may vary considerably.

Fig 3 depicts a constant radiance light source during the period tO while Fig 4 depicts a sinusoidal modulation of the light source radiance. The latter example is but one example of a range of modulations that can be applied to the light source falling within the capabilities of the source to be switched on and off with varying frequency and duty cycle.

While as previously mentioned, the voltage supplied to the light source could be used to vary the actual radiance of light source. Furthermore, the modulation technique adopted may be such as to control either the average, the peak or rms radiance of the light source as required to match various temporal emission templates.

It has been found advantageous to synchronise the modulation of the light source with the opening and closing of the shutter means. As depicted pictorially in Fig 4 the beginning of the modulation pattern is synchronised with the end of the rise time so that the effective radiance from the apparatus has continuity and remains in conformity with the required emission template.

WO 95/00813 PCTIAU94/00347 7 Filter 18 is located so as to filter the total emission of the light source 10 before it passes or as it passes out of the apparatus and is adapted in this embodiment to pass ultra violet light in the 225 to 420 nm wavelength band and further adapted to absorb the visible spectrum whLch may be emitted by the light source.

As mentioned previously, the control circuits 12 are powered by the power supply 11 and are adapted to control the radiance of the light source 10, the opening, period of opening and the closing of the shutter means 17 and the synchronisation of all of these actions so as to control overall the emission characteristics of the apparatus. Each emission template therefore is comprised of control parameters related to tr, tO, tf, modulation of the light source and the synchronisation of each of them with each other.

The control circuits 12 contain memory means 15a and and others if required, which are used to store a plurality of emission template parameters. Additional templates representative of variations of or additional offensive airborne weapon emission profiles can be easily added as new offensive weapon templates are determined or created for specific test purposes.

It will be apparent that the person skilled in the art will identify a number of mechanical and electronic equivalents to the element identified herein, however, this will not detract from the scope of the invention.

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Claims

2. Means to mimic the ultra violet emission of an offensive airborne weapon according to claim 1 wherein said control means is adapted to synchronise said shutter means with said modulation means so as to provide a smooth transition of the control of the spectral and temporal Semission of the apparatus.
3. Means to mimic the ultra violet emission of an offensive airborne weapon according to claim I further comprising .a spectral filter means positioned so as to pass a predetermined wavelength portion of the ultra violet spectrum from said apparatus.
4. Means to mimic the ultra violet emission of an offensive airborne weapon according to any preceding claim further comprising a storage means adapted to contain data representative of a plurality of shutter control characteristics and a plurality of modulation characteristics which are adapted to be combined to control said control means, said modulation means and/or said synchronisation means, to mimic the temporal spectral emission profile of an offensive airborne weapon. Means to mimic the ultra violet emission of an offensive airborne weapon according to claim 1 further comprising a hand held body within which said ultra violet light emission apparatus is contained which in use is adapted to allow an emission profile created by the apparatus to be directed towards said craft fitted with an offensive airborne weapon early warning device.
6. Means to mimic the ultra violet emission of an offensive airborne weapon with reference to and in accordance with the description and figures 1 and 2 of the specification.
7. A method of mimicking the ultra violet emission of an offensive airborne weapon to a craft fitted with an airborne weapon early warning device comprising the steps of: providing an ultra violet light source in a hand held .ou. housing; *0 .o 20 providing a shutter means operable to emit said ultra violet light out of said housing; providing a control means in said housing to operate said shutter means; operating said control means so as to generate an ultra violet light emission having a spectral and temporal emission profile of ultra violet light which mimics that of an 9g.. offensive airborne weapon; and directing said emission towards an airborne weapon early warning device fitted to said craft.
8. A method of mimicking the ultra violet emission of an offensive airborne weapon according to claim 7 comprising the further step of: (A i 011111 providing modulation means adapted to modulate said light source during the operation of the said shutter means.
9. A method of mimicking an offensive airborne weapon according to claim 8 comprising the further step of: providing a control means adapted to synchronise said shutter means with said modulation means so as to provide a smooth transition of the control of the spectral and temporal emission of the apparatus. A method of mimicking an offensive airborne weapon according to claim 9 comprising the further step of: providing a spectral filter means positioned so as to pass a predetermined wavelength portion of the ultra violet spectrum from said apparatus.
11. A method of mimicking an offensive airborne weapon according to either one of claims 9 and 10 comprising the further step of: .20 using a storage means adapted to contain data representative of a pluralj .y of shutter control characteristics and a plurality of modulation characteristics which are adapted to be combined to control said control means, said modulation means and/or said synchronisation means, to mimic the temporal spectral emission profile of an offensive airborne weapon and applying at least one of said sets of data to the control means. oe*. Dated this 9th day of December 1997. THE COMMONWEALTH OF AUSTRALIA By their Patent Attorneys MADDERNS