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CONFIGURABLE MODULAR SYSTEM FOR TESTING ALL TYPES OF ELECTRO-OPTICAL SYSTEMS

OECD CONFERENCE CENTER, PARIS, FRANCE / 2–4 FEBRUARY 2016

Krzysztof Chrzanowski (1), (2),(1) INFRAMET, Graniczna 24, Kwirynow, 05-082 Stare Babice, Poland, info@inframet.com

(2) Military University of Technology, 2 Kaliski Str., 00-908 Warsaw, Poland :

KEYWORDS: night vision, metrology ABSTRACT: A long series (over 40 test systems) of testsystems in many different versions is offered byInframet for testing all types of EO imaging&lasersystems. However, practically all these testsystems can be treated a single configurablemodular system shaped into many versionsoptimized for different applications. Thisconfigurable test system is built from a series ofbasic blocks: collimators, blackbodies, lightsources, rotary wheels, targets, laser viewingdevices, and meters. In this paper these basicblocks of systems for testing imaging and lasersystems are discussed. Technical challenges todesign these blocks are emphasized.

1 INTRODUCTION

Electro-optical surveillance technology covers awide range of systems: thermal imagers, VIS-NIRcameras, SWIR cameras, UV cameras, night vi-sion devices, laser range finders/ designators/illu-minators/pointers), multi-sensor surveillance sys-tems, and fused imaging systems. These differentEO systems have been developed by separatecommunities that typically specialize in one type ofEO system. Next, EO imaging and laser systemsare offered on market in myriad of differentversions.The same trend can be noted in area metrologicalequipment for testing electro-optical systems.Most test systems are optimized to testing onetype of EO systems. Great majority of test systemsis offered in form of a series of versions of differentdesign and different test capabilities.

2 INFRAMET UNIQUE MARKET POSITION

Inframet is one of manufacturers of equipment fortesting electro-optical imaging and laser systems.However, ultra wide offer puts Inframet on anunique position comparing to other manufacturers.Inframet basically can deliver systems for testingall types of electro-optical imaging and laser sys-tems and modules of these systems: thermal im-agers, night vision devices, VIS-NIR cameras,SWIR cameras, UV cameras, laser range finders,laser designators, laser trackers, laser pointers,multi-sensor systems, fused imaging systems, im-age intensifier tubes, IR FPAs, VIS-SWIR sensorsand optical systems.

A long series of test systems offered in many dif-

ferent versions is offered by Inframet for testingearlier mentioned types of imaging&laser systems.In detail, over 40 systems is offered, and almostevery system is offered in 3-10 versions. Thatgives high number of potential test systems thatcan be delivered by Inframet. However, practicallyall these test systems can be treated a single con-figurable modular system that can be built in manyversions optimized for different applications. Thisconfigurable test system is built from a series ofbasic blocks: collimators, blackbodies, lightsources, rotary wheels, targets, laser viewingdevices, and meters. In this paper these basicblocks of test systems are presented. Technicalchallenges to design these blocks areemphasized.

3 COLLIMATORS

Collimators are optical systems used to imitatestandard targets placed in "optical infinity" (verylong distance). The collimators are used for projec-tion of image of reference targets into direction oftested imagers. According to type of opticalelements used in design, collimators are dividedinto two groups: reflective collimators and refrac-tive collimators. Reflective collimators due to theirwide spectral range are almost exclusively used insystems for testing thermal imagers and are alsopreferable in systems testing VIS-NIR cameras,SWIR imagers, laser systems and multi-sensorsurveillance systems. Refractive collimators aremostly used in systems for testing night visiondevices or VIS-NIR cameras working in visible/near infrared range.

From optical designer view, the reflective colli-mators are inverted telescopes. Therefore it can beclaimed that there are many types of reflective col-limators depending on mirrors configurations(Newton, Cassegrain, Schwarzschild, Maksutov,etc). However, practically the reflective collimatorsare typically built using Newton design (bigparabolic primary, collimating mirror and smallersecondary flat mirror). Next, the reflective collimators are further dividedinto two types: on-axis collimators and off axiscollimators. The first collimators have a dead areain center of their optical aperture due to presenceof a non transmitting, secondary mirror. This fea-ture limits significantly applications of on axis colli-mators in systems for testing imagers. There is arisk that the dead area of the on-axis collimator candistort measurement results when only a part of

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aperture of optics of tested imager is used to cre-ate image. Off axis collimators offers un-obstructed aperturebecause the secondary mirror is located outsidecollimator aperture (Fig. 1). However, off axis re-flective collimators are also much more costly thanreflective on axis collimators. Low cost symmetric parabolic mirrors are used todesign on-axis reflective collimators. Nonsymmetric mirrors (parts of a bigger mothersymmetric mirror) are needed in case of off axiscollimators. Next, aligning of off-axis collimators ismuch more difficult than in case of typical on axiscollimators.

Focal planePrimary mirror

Secondary mirror

Fig. 1. Block diagram of off-axis reflective collima-tor (CDT series)

Fig. 2.Photo of several CDT off axis reflective colli-mators

Inframet manufactures a long series of CDT offaxis reflective collimators that are used as blocksof Inframet test systems or as independent opticalmodules.

Off axis parabolic mirror is the main block of offaxis reflective collimator. Present technology levelenables mass manufacturing of off axis parabolicmirrors of modest accuracy (L/1.5 at 630 nm P-V)from metal blanks [1]. Next, only mirrors ofaperture not higher than about 100mm can bemanufactured. Further on, the metal mirrors arecharacterized by relatively high roughness (up to17.5 nm RMS). These features makes off axismetal mirrors not suitable for typical off axisreflective collimators due to too small apertures,too low surface accuracy and to high surfaceroughness. Manufacturing of big, high accuracy offaxis mirrors from optical glass is still a domain ofoptical artists that must manually tune surface ofthe mirror to desired accuracy. Inframet posses a team of highly skilled opticaltechnologists capable to manufacture off-axis para-bolic mirrors of aperture up to 330mm (option 500mm) with surface accuracy up to λ/16 P-V atλ=630nm.

Inframet is also capable to manufacture simpleron axis reflective collimators and refractive collima-tors.

Fig. 3.Photo of several CVT refractive collimators

4 BLACKBODIES

Blackbodies are devices that work as near perfectemitters of thermal radiation in range from visibleto microwaves. There are many blackbodiesavailable on international market [2,3]. Inframet specializes in high-tech blackbodiesoptimized for narrow market of high requirements[4]. Almost all blackbodies offered by Inframet arecharacterized by some special features.

TCB series blackbodies are one of very few lowtemperature (max temperature below about 180ºC)blackbodies that can be controlled with 1 mK tem-perature resolution and with 2 mK temperaturestability. These blackbodies are optimized for usein systems for testing thermal imagers.

Fig. 4. A series of TCB blackbodies

MTB blackbodies are the only medium tempera-ture (max temperature below about 600ºC) black-bodies that can be controlled with 10 mK tempera-ture resolution and with 50 mK temperature stabil-ity. These blackbodies are optimized for use insystems for testing SWIR imagers or as referencestandards.

Fig. 5. A series of MTB blackbodies

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MAB blackbodies are the first commercially avail-able large area blackbodies of high emissivity inTHz and short microwave range offered at interna-tional market. These blackbodies have been devel-oped after several years of experiments carried outby Inframet research team. Design of theseblackbodies is based on a special castableabsorber coating optimized for THz/short mi-crowave range, large thermally uniform emitterplate and ultra precision control electronics. Highemissivity over 0.95 have been achieved in a widerange from 0.1 mm to 30 mm. Due to ultra large area, high emissivity, widespectral range and ultra precision temperatureregulation MAB blackbody significantly exceedsperformance of other microwave blackbodiesknown from specialist literature [5].

Fig. 6. MAB-16D blackbody

Testing infrared systems to be sent into space mis-sions is typically done using blackbodies locatedin cooled vacuum chambers that simulate spaceconditions. VSB blackbodies are a new type ofblackbodies offered by Inframet to meet demandsof space laboratories. This blackbody is designedto enable simulation of targets at temperaturesfrom -10°C to +200°C located at cooled vacuumchambers.

Fig. 7. VSB blackbody

UHT blackbodies are ultra high temperature, cavityblackbodies of temperature range up to 1600°C.Due to a special design of the cavity, UHT black-body offers high emissivity in exceptionally widespectral band from about 1 µm to over 3000 µm.This ultra wide spectral band makes possible touse UHT blackbody as a standard radiation source

in both infrared band and THz band. Theblackbody is also characterized by a relativelylarge aperture of 38 mm of the emitting cavity(apertures of typical high temperature blackbodiesare rarely bigger than 15 mm).

Fig. 8. Photo of UHT 38D-1500 blackbody

Each of earlier mentioned blackbodies representtechnical challenge for designers due to differentreasons.

Ultra precision, low noise electronics is the cruxin design of TCB/MTB blackbodies.

Special, ultra large emitter of ultra high emissivityin a broadband range from infrared to short mi-crowave is the main obstacle in design of MABblackbodies.

A similar situation is in case of UHT blackbodieswhere the main technical challenge is design ofcavity emitter of ultra high emissivity capable towithstand ultra high temperatures.

VSB blackbodies can be treated as a specialcase of TCB blackbodies. The requirements onelectronics are multiplied. The electronics mustenable not only control of blackbody with 1 mKtemperature resolution and 2 mK temperaturestability but additionally the electronics is expectedto work in vacuum and in extreme temperatures-173ºC to -33ºC.

5 LIGHT SOURCES

There are many low cost artificial light sourcesused for illumination or for industrial applications:tungsten or halogen bulbs, fluorescent lamps, LEDlamps etc. Some of these sources have regulatedintensity of emitted light. However, there very fewcalibrated light sources of precisely knownparameters. A light source can be considered ascalibrated when its user can precisely regulate itsphotometric/radiometric parameters like luminance(or illuminance), radiance (or irradiance) at definedspectrum of interest. Such light sources areneeded in many applications – among them, insystems for testing night vision devices, VIS-NIR cameras and SWIR imagers.

Inframet offers a series of calibrated light sourcesthat can be divides into three groups [6]:

1. Multi-channel halogen/LED light sources, 2. Single channel halogen light sources,

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3. Large emitter light sources. The light sources from the first group are opti-

mized to be used in Inframet systems for testingVIS-NIR cameras and SWIR cameras. Thesesources are expected to simulate illuminance con-ditions met in real life scenarios: from dark nightsin Afghanistan mountains to ultra bright days inArabian deserts. Such realistic simulation is possible only using lightsources of following features:1. Ultra high dynamic (ratio of maximal luminance

to minimal luminance) of light source at levelover 109 (needed to simulate both bright daysand dark nights),

2. Variable light spectrum in VIS-NIR range(needed to simulate variation of spectrum ofincoming light and variation of reflecting prop-erties of targets under surveillance),

3. Ability to emit high intensity UV light (needed tosimulate conditions met at coastal areas orhigh altitude mountains with high UV light thatare potentially damaging for some imagingsensors).

Two light sources codes as DAL/SAL belong tothe first group. These light sources work by com-bining light from several channels: halogen bulb of2856K color temperature spectrum and severalLED sources. Intensity of the halogen bulb is regu-lated using an opto-mechanical attenuator thatchanges light intensity but does not change lightcolor temperature. Intensity of the LED sources isregulated electronically using advanced electronicregulation/stabilization system. Intensity of UVLED is not regulated. Spectrum of emitted light canbe regulated by switching light channels or by mix-ing light from halogen channel with LED channels.Regulation of spectrum of emitted light is addition-ally supported by a set of external spectral filters. DAL/SAL light sources look externally the samebut there are some design differences: differentcoating of integrating sphere, slightly differenthalogen source and different LED sources. DAL isoptimized for testing VIS-NIR cameras sensitiveup to about 1000 nm; SAL – for testing SWIR im-agers sensitive up to about 1700 nm.

Fig. 9. Photo of DAL/SAL light source

DAL/SAL multichannel light sources due to ex-tremely wide range of regulated luminance, ul-tra high maximal luminance, ability to vary lightspectrum of simulated scenery, PC control,

and compact design significantly exceedsimpler, single channel halogen light sourcesoffered at international market [7]. DAL/SAL light source are designed to cooperatewith collimators in Inframet test systems. Theimage projectors (collimators) require from the lightsource Lambertian emission of light only in narrowangle (typically below 10°). Therefore DAL/SALlight source behave like a fully Lambertian sourceat emission angles up to 15°). This limited Lamber-tian performance is not acceptable in applicationswhere the light source is used as an independentblock. Next, there are applications when apertureof light emitter of DAL/SAL sources (40 mm) is toosmall. Therefore Inframet offers also H40 lightsource, L150 light source and H150 light source. H40 is a single channel source halogen lightsource that emit light of 2856K spectrum. Techni-cally it can be treated as a simplified DAL lightsource without LED channels and with modifiedlight emitter. Diameter of light emitter in H40sources is the same as in DAL/Sal sources(40 mm) but there are two important changes:a) Lambertian source at emission at angles up to60°, b)ability to cooperate with bright collimatorsof low F-number (ratio of focal length to aperturecan be as low as one). The second change means that by usingadditional bright collimator an apparent aperture ofthe light source can be increased (typically up to200mm) while still keeping sufficient emissionangle. Practically it means that H40 light sourcecooperating with a series of bright CRADrefractive collimators makes possible calibration ofVIS-NIR cameras or SWIR cameras with optics asbig as 200mm.

Fig. 10. Photo of H40 light source

Ability to calibrate VIS-NIR cameras and SWIRcameras of big optics can be also directly obtainedby using light sources of big emitter. Two suchlight sources are offered: L150 and H150.

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Fig. 11. Photo of H40 light source integrated withCRAD collimator

L150 is a single channel, ultra compact (thin de-sign) LED source that emits light using emitter of150mm diameter. Emission in different spectralbands is possible: visible, NIR or in SWIR. H150 a single channel, halogen source thatemits light using emitter of 150mm diameter.The source emits polychromatic light of 2856Kspectrum in VIS-SWIR range.

Fig. 12. Photo of L150 large area light source

Fig. 13. Photo of H150 large area light source

The series of earlier presented light sources can fitfor virtually all applications when reference lightsource is needed.

6 ROTARY WHEELS

Rotary wheels are one of basic blocks of sys-tems for testing imaging EO systems. They areneeded to enable motorized exchange of active

target at collimator focal plane. There are usually8 holes in the wheel for targets (other numbers arealso possible). Wheels are covered with a blackhigh emissivity coating (emissivity at least 0.97). Design of rotary wheels look apparently simplebut practical manufacturing is no so easy. Ultraprecision positioning (high repeatability) of thewheel is the main design challenge. Positioninguncertainty of the rotary wheel at level below 0.1mm is expected in case of systems for testingimagers used for automatic target recognition.

Fig. 14. Photo of MRW-8 rotary wheel withattached TCB-2D blackbody blackbody

7 TARGETS

Targets are modules needed to generate images ofreference patterns. INFRAMET divides test targetsaccording to intended main application into twomain groups: A) IR targets, B)visible targets,

Targets from group A are developed to supportmostly testing infrared imaging systems under-stood as thermal imagers. These targets can beused also in testing visible/near infrared camerasor SWIR cameras but such application is not opti-mal.

Targets from group B are developed to supportmostly visible/NIR systems. These targets can bealso optionally used for testing most SWIR im-agers.

a) b)

Fig. 15. Images of test targets generated by testedimagers a)image of 4-bar IR target, b) image of visible

USAF 1951 target

IR targets for testing infrared imaging systems(thermal imagers) are manufactured by creatingprecision holes in metal sheets of different shapes.When a blackbody is put behind such a target,

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the tested thermal camera sees a "target" of shapedetermined by the holes on an uniformbackground. The apparent temperature of this"target" is equal to blackbody temperature.

Fig. 16. Photo of two 4-bar IR targets

Targets for testing VIS-NIR cameras are typicallymanufactured by creating non-transparent (orsemi-transparent) coating pattern on transparentglass substrate. This method enables develop-ment of test patterns with sub-micrometer accu-racy.

Fig. 17. Photo of USAF 1951 target of 100% con-trast

There are two main technical challenges tomanufacture high quality targets needed to test EOimaging systems. Manufacturing ultra precision holes (rectangles assmall as 0.03 mm are needed) in metals sheetscoated using high emissivity paint is the main prob-lem for successful manufacturing of IR targets. Making uniform low contrast resolution patternson glass substrates is the main difficulty in manu-facturing visible targets. At present Inframet is the only company oninternational market that offers USAF 1951resolution targets of contrast as low as 2%. Suchtargets are needed to evaluate ability of VIS-NIRcameras to detect low contrast camouflagedtargets.

8 PULSED LASER VIEWING DEVICES

Visualization of laser spot created by tested laserrange finder is one of basic task of a system fortesting multi-sensor surveillance systems. Imageof laser spot created at focal plane of a collimatoris needed to evaluate alignment of laser rangefinder (LRF) relative to imaging sensors (thermalimagers, VIS-NIR camera, SWIR camera) and tomeasure divergence angle of LRF.

Sensing cards that can visualize position oflaser beam emitted in UV or IR range are knownfor decades as a low cost solution to view laserspots invisible for human eye [8,9]. The cards are

typically built using layer of phosphor or liquidcrystal as imaging sensor. The phosphor screenconvert directly incoming invisible laser light (UV orIR) into visible light : the spot illuminated by laserstarts to emit visible light. In case of cards based on liquid crystals the con-version of radiation from IR laser to visible light isdone indirectly. Radiation from IR laser is absorbedand changes temperature of liquid crystal layer.Change of temperature generated change of colorof the card that is visible for human eye.

There are also known more advanced and accu-rate devices for visualization of invisible laserbeams : 2D mechanical scanners and UV/IR cam-eras [10]. However, all earlier described methods have beendeveloped to visualize beams of CW lasers. Theyare useless or of limited usefulness in case ofpulsed lased used as transmitters in LRFs or laserdesignators due to a set of different reasons.

Almost all LRF and laser designators operate inrange from 905nm to 1570nm. Majority of profes-sional LRFs/designators use transmitters thatemits short, high energy pulses at one of wave-lengths 1064/1530/1550/1570nm (monopulseLRFs built using laser modules); or emits a seriesof long, low energy pulses at wavelength about1550nm (multipulse LRFs built using laser diodes).

Monopulse LRFs will damage earlier describedlaser sensing cards due to extremely high pulseenergy. Next, sensitivity of these cards is too low tovisualize laser post created by multipulse LRFs.Further on, mechanical beam scanners are notconvenient due to long time needed to generate2D profile of laser beam. The latter featureeliminates this method in cases of LRFs fixed togimbal platforms that have never fully fixedangular position.

SWIR cameras can accurately visualize 2D pro-files of laser spots created by multipulse LRFs.However, in case of testing monopulse LRF shortpulses of ultra high peak power (over 1 mW) gen-erates significant crosstalk between pixels of IRFPA and obtained image of laser spot issignificantly blurred.

Burn paper is the only low cost and commonlyknown method that work relatively well in case ofmonopulse LRFs/designators. Burn paper is un-derstood as a series of materials that change re-flectance (apparent brightness) when irradiatedby high power laser pulses [11]. It means that asingle laser pulse burns image of laser spot : it canbe dark spot on brighter background or inverse).Creation of burn image is not reversible ; theburned spot cannot be later removed.

Photographic paper was a dominant type ofburn paper in past. Nowadays there are many lowcost materials that can be used as the burn pa-pers. However, there are several disadvantages ofburn paper cards. First, image on burn paper card gives only ap-

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proximate information about true 2D profile of laserspot. The image depends on power of incomingpulses and material properties of the card. Second, burn paper cards create images that arevisible only to VIS-NIR cameras. These images arenot visible in MWIR/LWIR bands and the cardscannot be used to align axis of thermal imagersand of axis of LRFs. Third, each laser pulse creates a single burnedspot that cannot be removed. Therefore a seriesof burn paper cards is needed for testing a seriesof LRFs.

In this situation Inframet has developed a seriesof techniques of visualization of laser beams emit-ted by LRF/designators. They can be divided intothree main groups:

1. Classical non-reversible burn paper cards,2. Reversible burn paper cards,3. SWIR imagers of ultra high dynamic.

MON cards and MOG cards offered by Inframetbelong to the first group. When irradiated by trans-mitter of monoipulse LRF/designator the card cre-ates a burned image of laser spot that becomesvisible to VIS-NIR camera. The MOG card isabout six times more sensitive than MON card.These cards enable accurate boresight ofmonopulse LRF/designators relative to visiblechannel (VIS-NIR camera). The cards need re-placement when many laser spots are created onthe surface of the card.

Three next cards coded as TEG, TEP and ABSbelong to the group of reversible burn paper cards.TEG/TEP cards are to be used for testingmonopulse LRFs/designators and ABS card is tobe used for testing multi-pulse LRFs. The TEG/TEP cards generate transient image oflaser spot that can be seen by both thermal im-agers and VIS-NIR cameras. In other words,the TEG/TEP cards work as convertors of SWIRradiation into VIS light and MWIR/LWIR radiation. ABS cards is the most sensitive version of the re-versible burn paper cards optimized for use withlow power multipulse LRFs. These cards createtransient image seen only by thermal imagers.

Fig. 18. Photo of several laser sensing cards

Both classical non reversible burn paper cardsand reversible burn paper cards are low cost butefficient tools to carry out boresight of

LRFs/designators relative to imaging systems.However, the cards can be used only for roughdetermination of divergence angle ofLRFs/designators. SWIR imagers are needed foraccurate measurement of divergence angle ofLRFs/designators and to improve accuracy ofboresight of LRFs relative to imaging systems.

Basically any SWIR camera offered on the mar-ket can be used to measure divergence angle ofmulti-pulse LRFs. These LRFs emits a series ofhigh frequency optical pulses and create a tempo-rally stable image. The real challenge is capturingimages of laser spots generated by pulses frommono-pulse LTFs/designators. Time width of suchpulses vary from 4 ns to about 100 ns and peakpulse power can be as high as 10 MW.

It is technically possible to use optical attenua-tors and reduce of irradiance at plane ofthe imaging sensor to level safe for the sensor.However, pulse time width of incoming laserpulses is roughly 106 shorter than frame period intypical SWIR cameras working at 50 FPS speed.It means that peak pulse power during tests ofLRFs/designators is millions time higher than dur-ing typical camera work. This situation is reason forstrong blurring of image of laser spot observed inimages captured using typical SWIR cameras.Recorded 2D profile of laser spot is significantlydistorted and measured divergence angle can beeven two time bigger than true value.

Fig. 19. Photo of SR2 imager

Inframet has developed an SWIR imager (codedas SR2 imager) optimized for capturing images oflasers spots created by LRFs/designators. Bothtypes of LRFs (monopulse and multi-pulse)operating at wavelengths in typical band fromabout 900nm to about 1570nm can be tested.

The SR2 imager is built using using an imageconverter lamp integrated with CCD camera.Photocathode of the converter lamp is sensitive upto about 1800nm and is capable to withstand ultrashort powerful optical pulses with negligible imageblurring. A set of exchangeable attenuators makespossible effective capturing images of laser spots

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from both low power multi-pulse LRFs and ultrahigh power monopulse LRFs. The imager ishighly linear and output brightness is proportionalto power of incoming laser radiation.

9 METERS

Blackbodies and light sources presented in previ-ous sections need to be calibrated. Therefore In-framet has developed two meters (TM6 tempera-ture meter and LM1 luminance meter) that areused for calibration of blackbodies and lightsources [12].

Fig. 20. Photo of TM6 temperature meter

Fig. 21. Photo of LM1 luminance meter

TM6 meters are ultra-precision, ultra-stable tem-perature meters. The meters are characterized byvery good temperature resolution and measure-ment uncertainty. Measurement resolution is 1 mKand is at least 10 times better than resolution oftypical temperature meters offered on internationalmarket. TM6 meters have been designed using electroniccomponents of ultra-low temporal fluctuation oftheir parameters. Further on, advanced auto cali-bration circuitry was used. All these features en-abled to extend recalibration interval of the TM6meters to six years in case of calibration of black-bodies used for testing imagers for surveillance ap-plications or three years in case of imagers for noncontact temperature meters used in measuring ap-plications. LM1 is a precision luminance meter optimized fortwo basic applications: A) as an external meter instations for testing night vision devices, B) as a toolfor recalibration of light sources (DAL, SAL, H40,H150, L150). In case of type A application the LM1

meter is used for measurement of luminance of im-age intensifier screen seen via oculars. Aperture ofoptical objective of the LM1 meter is optimized fortesting night vision devices (below 8 mm). In caseof application type B the LM1 luminance meter isused as a small, portable meter that is sent for re-calibration to Inframet facilities (or any calibrationlaboratory that specialize in photometric calibra-tions). Later the LM1 meter is used for recalibrationof earlier mentioned light sources.

10 CONCLUSIONS

Inframet manufactures equipment for testing alltypes of electro-optical imaging and laser systemsand modules of these systems: thermal imagers,night vision devices, VIS-NIR cameras, SWIR cam-eras, UV cameras, laser range finders, laser des-ignators, laser trackers, laser pointers, multi-sensorsystems, fused imaging systems, image intensi-fier tubes, IR FPAs, VIS-SWIR sensors and opticalsystems. These ultra expanded test capabilitieshave been achieved by development of a longseries of blocks (collimators, blackbodies, lightsources, rotary wheels, targets, laser viewingdevices and meters) that are used to builtdifferent modular test systems.

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