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Sensor Alternatives for Future Unmanned Tactical Aircraft

E. L. FleemanThe Boeing Company

3370 Miraloma AvenueAnaheim, CA 92803 U.S.A.

SUMMARYThis paper addresses he enabling technologies of thesensor suite for the next generation UnmannedTactical AirnaR (UTA). An assessment is made dtarget sensors, communication sensors, andnavigation sensors that are used in the UTAintelligence, surveillance, reconnaissance, communi-cation, and target designation missions. Emphasis is

given to the classes of UTAs that operate at stand-offaltitudes and ranges outside the effectiveness envelopeof typical threat air defenses and ammers.

Primary environmental factors that are addressed inthe paper are world-wide cloud cover and rain rate.The effects of cloud cover and rain rate on sensorperformance are evaluated for synthetic aperture radar@AR), passive millimeter wave (mmw), and electro-optical (EO) sensors. The synergy of radar kequency(RF) sensors to improve the sensor suite performancein cloud cover and rain rate is addressed.

The paper also addresses the enabling technologies

that are required for real time, low false alarm rate(FAR), automatic target recognition (ATR) andprecision targeting. A target sensor suite is postulatedthat is based on multi-spectral, multi-dimensiondiscriminants of the target. An X-band or Ku-bandSAR is considered to be the best overall target sensorfor UTA applications. A priority ranking of othertarget sensors is ultra wide band (UWB) lowfrequency SAR, forward looking infrared (FLIR), laserinfkcd detection and ranging (LIDAR), visible, andpassive mmW. The Year 2007 sensor suite wouldcover the multi-spectral range of VHF fkquency tovisible waveIength and the multi-dimensional para-meters of contrast, two-dimensional shape, three-dimensional shape, temporal, and polatizationsignatures of the target.

LIST OF ACRONYMS AND SYMBOLSDefinition

AIJ Anti-JamADTS Advanced Detection Technology SensorATR Automatic Target RecognitionC-band 3.6 GHz to 7.0 GHzC/A Course AcquisitionCALCM Conventional Air Launched Cruise

MissileCARABAS Coherent All Radio Band Sensing

CCDCCMCdZnTeCL0D

z&IERIM

FARFMFMCW

FOGFOVFPAGPSHgCdTeHzIDIFOV

IlRINSInSbIRITCZI&bandKu-bandLADARLIDARLOLWIRMBEmmWMWIRPACE

PFMP(Y)POGOPtSiQWIPRRCSRFRLGRSS

Charge Coupled Devicecounter-CountermeasureCadmium Zinc TellurideCounter Low ObservableDiameterDecibelDigital Quartz IMUEnvironmental Research Institute of

MichiganFalse Alarm RateFrequency ModulationFrequency Modulation ContinuousWavelengthFiber Optic GyroField of ViewFocal Plane ArrayGlobal Positioning SystemMercury Cadmium TellurideHertz (cycles per second)IdentificationInstantaneousField-of-View (fieldaf-view of one resolution cell)

Imaging InfraredInertial Measurement UnitInertial Navigation SystemIndium Antinimide

Inter Tropical Convergence Zone-35 GHz-17 GHzLaser Detection and RangingLaser Infrared Detection and RangingLow ObservableLong W ave I&aredMolecular Beam EpitaxyMillimeter WaveMedium Wave InfkedProducible Alternative to CadmiumTelluride for EpitaxyPulse Frequency ModulationMilitary Code for GPS ReceiversPrecision On-Board GPS OptimizationPlatinum SilicideQuantum Well Infrared PhotodetectorRange to TargetRadar Cross SectionRadar Frequency or Radio FrequencyRing Laser GyroRoot Sum of the Squares

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SAR Synthetic Aperture RadarSATCOM Satellite CommunicationS&IF-band Super High Frequency BandSIGINT Signal IntelligenceSOTA State-of-the-ArtSWIR Short Wave Infrared

TBD To Be DeterminedTESAR Tactical Endurance Synthetic Aperture

TLETVUHF-band

UTAuvVHF-bandWWAGEW-bandX-band

CL

Target Location ErrorTelevisionUltra High Frequency BandUser Range ErrorUnmanned Tactical AircmftUltravioletVery High Frequency BandWeightWide Area Guidance Enhancement-94 GHz-10 GHz

Is similar toMicron ( IO4 meter)

1. INTRODUCTION/OPERATIONAL TRENDSOF THE YEAR 2007

Until recently, most Unmanned Tactical A&raft(UTA) used a relatively unsophisticated sensor suitethat typically consisted of a FLIR sensor, a television

(TV) camera, and a data link. However, the morerecent UTAs, such as Predator, are beginning to carrysophisticated sensor payloads, including multipleinfixed (IR) sensors and SAR sensors, that broadenthe range of missions and mission performance.Improvements in UTA sensor capability are expected

to continue into the next generation multi-missionUTAs. Drivers for the next generation UTAs, thatwill require improved sensor capability, include abroad range of missions, enhanced survivability, widearea/continuous coverage of the target area, real timeATR, low False Alarm Rate (FAR), and real timeprecision targeting.

Table 1 shows a typical capability of current UTAscompared to a projected typical capability of the year2007. The General Atomics Predator UTA wasselected as an example of recently introduced UTAs.Other UTAs such as Pioneer and Hunter are lesssophisticated than Predator, while developmental

UTAs such as Global Hawk and Dark Star will bemore sophisticated than Predator. The sensor payloadof Predator includes an EO sensor suite, a Ku-bandSAR sensor, Ku-band and UHF-band satellitecommunication (SATCOM), a C-band line-of-sightdata link, and a Global Positioning System (GPS)/Inertial Navigation System (INS) navigator.

Table 1. UTA Capability Forecast

Typical UTA Capatdlty UTA ConceptTBD

l Maximun Flight#titukl MaximumSensorSlantRangel MaximumFlight Durationl MaximumVelocity

0 SersorPayloadWeightl Real-ZmeATR

Next generation sansom will providereal-time AIR and pm&n

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The Predators EO sensor suite is the VersatronSkyball SA-144/18 Quartet sensor. It consists of aPtSi 512 x 512 MWIR FLIR, a color TV camerawith a 10X zoom, a color TV 900 mm camera, andan eyesafe pulsed erbium: glass laser range finder,The diameter of the EO sensor turret is relatively

small--35 cm. The turret has precision pointing witha line-of-sight stabilization accuracy of 10 prad.

to the target area. The current emphasis on reducedobservables is expected to continue, with tirtureUTAs having lower observables.

The Predators SAR sensor is the NorthropGrumman (Westinghouse) Tactical EnduranceSynthetic Aperture Radar (TESAR). TESARprovides continuous, near real time strip-maptransmitted imagery over an 800 meter swath at slantranges up to 11 km. Maximum data rate is 500,000pixels per second. The target resolution is 0.3meters. TESAR weight and power are 80 kg and1200 watts respectiveiy.

Advancements in sensor capability are expected toinclude real time ATR, orders of magnitude reduction

in FAR, and an order of magnitude improvement intargeting accuracy. The advanced sensors willleverage the current advanced development (categoiy6.3A funding) activities that are presently under way.

2. ADVERSE WEATHER CONSIDERATIONSIN SENSOR PAYLOAD

Weather is a driving consideration in the selection da sensor payload suite. Although a UTA usuallyoperates at high altitude above the weather, the sensorsuite must be able to see ground targets throughadverseweather.

Also shown in Table 1 is a projected capability for a Cloud cover is a particular concern for UTA sensors

hypothetical UTA introduced in the year 2007. It is because clouds are pervasive in the world-wideanticipated to have a broad range of missions weather. The global average annual cloud cover isincluding surveillance, reconnaissance, communica- about 61 percent, with an average cloud cover overtion, intelligence gathering of threat electronic land of about 52 percent and an average cloud coveremissions, target designation for weapons attacking over the oceans of about 65 percent, The averagemoving targets, and communication relay. The annual cloud cover shown in Figure 1 is based onsystem flight perfonnanee is expected to be greater weather observers around the world. It is a compositethan present UTAs, with higher velocity, providing a of avemges that vary widely with geographicallarger area of coverage and faster response in getting location, season,and time of day.

Reference:Schneider, tephenH., Encyclopedia f Ctlmate nd Weather,OxfordUniversity ress, 996.

Figure 1. Cloud Cover Climatology

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An example of a geographical cloud system thatchanges regularly with the season and the time of dayis the low-level, layered stratus clouds that covermuch of the worlds oceans. Skatus clouds are morelkquent during the summer months of the EasternPacific and the Eastem Atlantic and in the hours

before sunrise.

those of the Southern Hemisphere. Cumulonimbus

Another example of a geographical cloud system thatchanges regularly with the seasonand the time of dayis cumulonimbus. Cumulonimbus are large columnarclouds that can extend to high altitude. These cloudsam concentrated where sutike temperatures are highand there is a general upward movement of the air.An example is a zone known as the IntertropicalConvergence Zone (ITCZ). In the ITCZ, the tradewinds of the Northern Hemisphere converge with

have high concentrations of droplets and ice crystals,which can grow to a large size. Cumulonimbus areoften responsible for the frequent summer afternoonrainfal! of South East Asia, North America, andEurope, and the December, January, and Februaryrainfall of the Amazon basin.

Rain rate is another consideration in sensor selection.Figure 2 shows the world-wide average annual

season, and time of day.

precipitation (rain and snow equivalent rain)haracterized as wet (greeter than 1500 mrrdyr),

Lmperate (between 250 mm& and 1500 mm/yr),and arid (less than 250 mm/y+ It is noted that over90 percent of the world receives less than 1500mm/y-r rainfall. It is also noted that cloud covervariations due to geography, season, and time of dayare reflected in the rainfall variations with geography,

Referenc& Smalt Waapon s Specifi&i~ Guide, U.S. Army Smart WeaponsManagement office, R edstone Arsenal, Alabama, Octokr 1990

Figure 2. Rain Climatology

DTA sensor attenuation is greater for rainf&ll from

high altitude clouds. There is a longer path lengththrough the rain for high altitude clouds than for lowaltitude clouds. Figure 3 shows the probability afcloud height for the temperate, wet, and arid regionsof the worlds land mass. Note that clouds in aridregions tend to occur at higher altitudes while theclouds in the temperate and wet regions tend to occurat lower altitudes. Clouds tend to occur at a height CE1.0 to 5.0 km altitude. .

Figure 3 also shows the probability of rain rate for a

temperate region of the world that has a relativelyhigh annual rainfall. The average probability of norain is 80 percent for this region. The probability drain rate less than 4 mrruhr is very high--96 percent.Also shown for comparison is an averageprobabilityof rain rate for the Middle East. The probability of norain is very high--96 percent and the probability afrain rate less than 4 mm/br is even higher--99percent.

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1

_ ---- ---- 1-1_11--___.----- --------1

CloudBaseMeiiht (km)loudBaseMeiiht (km)

b Clouds end to occur at a base height of 1 to 5 km altitudelouds end to occur at a base height of 1 to 5 km altitude

b Predominant ain rate is less han 4 mm/hrredominant ain rate is less han 4 mm/hr

ileferance: SmartWeaponsSpecification uide,U.S.ArmySmartWeaponsleferance: SmartWeaponsSpecification uide,U.S.ArmySmartWeaponsManagement ffice,Redstone rsenal.Alabama,October 990anagement ffice,Redstone rsenal.Alabama,October 990

Figure 3. Adverse Weather Performance Requirements

For the purpose of this assessment, a maximum to 5 km of path length through the rain. Thecloud base height of 5 km, a maximum cloud implications of blockage by clouds and the relativelythickness of 2 km, and a rain rate of 4 mm/hr are short range in rain are that (1) the UTA will have toconsidered to be cost effective requirements for UTA descend to low altitude in order to acquire target datasensors. It would be unnecessarily restrictive to using EO sensors, or (2) the UTA will wait for arequire UTA sensors to operate in 100 percent cloud break to use EO sensors, or (3) use only the

weather conditions, such as severe thunderstorms. radar sensors.

Figure 4 shows the attenuation versus wavelength fbra representative cloud, rain rate, and humidity levelrequirement. Note that although passive EO sensorshave one-way transmission through rain of about 50percent per km, there is almost no transmission of anEO signal through clouds. Cloud droplets are small,about 5 to 20 microns in diameter, with dimensionscomparable to the EO wavelength. The concentrationis high--about 50 to 500 droplets per cubiccentimeter. EO wavelengths are strongly di&ctcdaround cloud droplets due to Mie electromagneticscattering. However, rain drops are about 2-6 mm

diameter (much larger than EO wavelengths) andcause less attenuation to an EO signal. Rain rateattenuation is due primarily to optical scattering. EOtransmission through rain is a fnnction of the size cfthe rain drops, rain rate, and the path length throughthe rain. EO passive sensors are limited from about 2

The best sensors in looking down through cloudcover and rain are radar sensors. Radar sensors havenegligible attenuation at tiequencies below IO GHz.At higher trequencies, passive millimeter wavesensors operating in cloud cover and rain are limitedfrom about 2 to 5 km length of path through theclouds and rain, with the same implications as thosediscussed in the previous paragraph. Cioud droplets,which are much smaller than mmW wavelengths,absorb mmW radiation (much like a microwaveoven). A different mechanism is responsible for theattenuation of a mmW signal through rain or snow.

Rain drops and snow flakes are comparable in size tommW wavelengths and cause Rayleigh and Mieelectromagnetic scattering attenuation. LoWtTfrequency Ku-band sensors are less a&ted by cloudcover and rain rate.

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AmENUATlON SY ATMOSPHERIC GASES, CLOUDS, AND R*IN (PROM PRIESSWR, ISTS)

noC:-- - SO mnutbn thrwgh

ckwdOO.lpnJm*ti100 111 ldbllity

.I ., IEO pmunbn thmu~hnln m 4 mrnlkr---.nrmlak y 0 7.5gmhnr_ _ Yllllmam - mid

mbmrm4twnrutbnIhmu@h cbud 0 0.1gwmwnlno4m~r

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c)I147*, FREGEi%cHTAVELENG?

F EOsensorsare ineffective hroughcloud coverb Radarsensorshave good o superiorpeFformancehrough cloud cover and rain

Figure 4. Signal Attenuation Due to Weather

3. SENSOR TECHNOLOGY EXPLOTTATIONOF THE YEAR 2007

An overall summary comparison of target sensoralternatives against UTA measures of merit is givenin Figure 5. The measures of merit selected for theUTA missions are: performance in an adverse weatherenvimnment of cloud cover and rain; target resolutioncapability; contrast of the target to the backgroundclutter; multi-dimensional target discriminants in the

areas of polarization, temporal, and shape signaturesthat are used in ATR; multi-spectral discriminantsmoss a broad range of ~ucncy and wavelength thatare used in ATRs; and weight/cost. The adverxweather measures of merit of p&mnance throughclouds and rain rate were discussed in Section 2.Figure 5 is based on the assumptions of a cloudthickness of 2 km, a cloud base height of 5 km, and arain rate of 4 mm&r.

wwthrGwd ! Rdn r

0 Average - Poor

WdLtrndcw!

00

1 igure 5. Target Sensor Suite Performance Projected to Multi-Mission IJTAs of the Yenr 2007

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spectral discrlminants that provide enhanced detectionat longer range.

Referring back again to the Figure 5 assessment dUTA sensor alternatives, the fourth priority sensor inan overall sensor suite to detect low observable

targets in clutter is Laser Mared Detection andRanging (LIDAR), also known as LADAR. LIDARprovides unique three dimensional high resolutionand temporal information (e.g., target skin vibration,target exhaust gases) hat complement the passive IRsensors of a multi-spectral, m ulti-dimensional sensorsuite, The LIDAR transmitter is usually boresightedto an IR FPA sensor that acquires and tracks thetarget, The capability to simultaneously measure thepassive IR signature and compare it to the reflectedLIDAR signature t%om he laser enhances the ATRperformance.

A technology currently in development that will

enhance he application of LIDARs is tunable lasers.Tunable LIDARs provide a broader band dwavelength for multi-spectral ATR.

Target designation is a mission that can be addressedby a LIDAR sensor, The UTA sensor suite wouldhand off target coordinates to the LIDAR for trackingand laser designation. Laser guided weapons launchedhorn manned a&raft platforms would then home onthe laser designated target with precision accuracy. Itis postulated that UTAs that are designated to carryweapons as part of a primary mission will not occuruntil after the year 2007 time frame. An operationalcapability in the year 2007 was used as an

assumption in conducting the technology assessmentfor this paper.

Referring back again to Figure 5, the filib prioritytarget sensor of a UTA target sensor suite would be avisible light multi-spectral camera. Advantages of aTV sensor include high resolution due to the shortwavelength and an additional discriminant of thepolarized reflection of sunlight. Although a TVsensor is not e&c& in cloud cover or at night, along duration flight UTA could perhaps revisit thetarget area when appropriate.

Visible detectors are a more mature technology than

IR detectors. The detectors are fabricated from silicon,

using many of the processes already developed forcommercial integrated circuit manufacturing. Thevisible detector FPA and readout circuitry are usuallyMricated in a one piece, monolithic sensor. Largesize visible detector arrays are currently indevelopment with array sizes larger than 5000 x

5000. The current .SOTA in center detector spacing(pitch) for visible FPAs is 8 to 12 microns.

Referring back to Figure 5 for a final time, note thestrengths and weaknesses of passive mmW sensors.Passive mmW sensors have an advantage over EOsensors n their capability to see through cloud coverand the high con trast of metal objects in the mmWspectrum (see Figure 7). Advantages over active RFsensors nclude lower noise and the avoidance of radarglint. The cold sky (about 35k) is reflected by metalobjects at mmW frequencies while the temperature Bterrestrial object clutter is about 300k. Currentradiometers can typically detect differences in

temperature of lk and radiometers are in developmentthat will detect dif%rences in temperature of 0.1 k,providing a very high signal-to-noise ratio of morethan 300 to 1.

Passive mmW cameras similar to video cameras areunder development by TRW. Cameras have beenground tested at 60 GHz, 65 GHz, 89 GHz, and 95GHz frequencies. Array sizes up to 40 x 26 elementshave been produced. Apertures that have beenproduced to date range in diameter lbnn 0.4 meter to0.6 meter. Frame rate demonstrated to date is 17 Hz.Airborne flight tests are planned in late 1997 to flightdemonstrate a passive mmW sensor.

Disadvantages of passive mmW sensors includerelatively low resolution compared to EO and SARsensors and attenuation in cloud cover and rain rate.However, passive mmW technology is relativelyimmature and future passive mmW sensors of thepost-2007 time frame will have distributed aperhuesfor operation as a high resolution interferometer.Distributed apertures consisting of ten or more widelyspaced apertures could provide an effective aperturethat would be comparable to the wing span of theUTA.

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Range o QueenMary: 500 m

Msible tight Phutugrzqvh

TRW84 G#z RadiomeMc Image

Passive mm W sensor provide high contrast of metal of&c&+ Q=m-llQIM.

Figure 7. Passive Imaging mmW View of Queen Mary and Spruce Goose Dome

Sensor tracking errors due to the enor slope of aconventional hemispherical dome are a traditionalproblem for EO and RF sensors. Small imperhectionsin the shape of a hemispherical dome greatly affect thetracking accuracy. An approach that alleviated theproblem for EO and RF domes on ballistic missiledeft interceptors is to use a flat window as adome. The error slope of the flat window is nearlynegligible compared to a traditional curvedhemispherical dome. Another advantage of a flatwindow for sensors s reduced observables. A grid orslotted film over the window can be tuned to be IR orRF transmissive in the wave length or frequency cfinterest and RF reflective for out-of-band frequencies.This results in reduced RF back scatter to threatradars, providing reduced radar cross section (RCS)for the UTA. Figure 8 shows experimental andpredicted results of the RCS of a treated flat gridpyramidal shaped set of windows compared to aconventional treated hemispherical dome. The 1.5 to1 length-to-diameter ratio pyramidal flat gridwindows provide more than -20 dB reduction inRCS compared to a conventional 0.5 to 1 length-to-diameter ratio hemispherical dome.

As mentioned previously, the current SAR systemsgenerate a tremendous amount of data, driven byrequirements for high resolution and large swathwidths. The extension of SAR polarization will drivedata rates even higher, Communication systems anddata links handling capability will need to increase inthe future to handle the increased amount of on-boarddata. Future data transmission systems will use splitdata links to relay satellites, ground stations, mannedaimraft, or other UTAs. UTA data transmission andstorage rates SOTA at the present time are of theorder of 50 to 100 Megabits per second.

Phased array antennas are in development thatprovide high data rate (-600 Megabits per second)and flexibility for a UTA to rapidly and efficientlycommunicate with satehites, ground stations,manned aim&, or other UTAs. Phased anayantennas may also be applicable to agile, highlyaccurate electronic signal intelligence (SIGINT). Aconcern in applying phased array antennas to an intelmission is the mission may require operation over avery broad band (e.g., 500 MHz to 35 GHZ) that isoutside the SOTA of phased array antennas tbrUTAs.

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Figure 8. Flat Grid Windows for Sensors

Boeing is developing a family of low cost, high developed in the SHF-band, Ku-band, and Ka-band.perfomxwe phased array antennas for airborne Airborne flight tests have been conducted on military,communication (Figure 9). Planar devices have been commercial, and genera1 viation aircraft.

2nd Generation Planar)Architecture

SHF

Low-Cost 91 Element, 20-GHz,Phased-ArrayAntenna Honeycombs Ku-Band Flight Hardware

Figure 9. Boeing Phased-Array Family for Mobile Communications

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Precision targeting with accuracy better than 3 meterswill require high performance navigation sensors. Thec-t Global Positioning System (GPS) receiversoperating in a military P(Y) code have an accuracy dapproximately 6 meters. Recent advances in usingGPS in the Wide Area GPS Enhancement (WAGE)

mode, differential mode, or relative mode, combinedwith SAR precision mapping, have the potential toprovide target location with an error less than 3meters.

Figure 10 illustrates examples of GPS receivers andinertial sensors that are currently being used inGPSINS navigation. Inertial sensors that are cur-rently available include those baaed on ring lasergyros, fiberoptic gyros, and digital quartz gyros. Anemerging technology is a Micromachined Electro-

Mechanical Sensor (MEMS) that is fabricated Corn asingle piece of silicon. Good performanceis achievedin a small size, low cost package. Between 2,000 and5,000 devices can be produced on a single fiveinchsilicon wafer.

Fiber Optic Gyro

GPMNS Receiver

Figure IO. Example of Navigation Sensors

Figure 11 illustrates the advantages of GPS/lNS inte-gration. Benefits of GPSANS integration include highprecision position and velocity measurement, reducedsensor noise, reduced jamming susceptibility, andattitude measurement capability. A UTA operating ataltitudes higher than 8 km with a modern GPSreceiver will have low susceptibility to jamming.The availability of GPS to continuously update theinertial system allows the design trades to consider alower precision and less expensive INS, while main-taining good navigation accuracy and anti-jam (A/J)

Future GPS/INS receivers will be based on acenlralized Kahnan filter that processes the raw datafrom alt of the sensors (e.g., SAR, GPS receiver,INS). Tightly coupled GPS/INS is more robustagainst jamming because t is able to make pseudo-range measurements li-om three, two, or even onesatellite if one or more of the satellites are lost.

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Reduced Pi&on and Ye/o@ Gro rs

t INS GPS I

TlmE ThleReduced Jamming hc@IbMty

* WAGE,UHfnrential,r raiatlve GFG

Figure 11. Why GPSlINS Integration?

The 6 meter GPS standard accuracy is improvedwhen multiple GPS measurements are combined in aKalman filter that provides a calibration of GPS andlNS errors. An example shown in Figure 12 is aConventional Air Launched Cruise Missile(CALCM) demonstration called Precision On43oard

GPS Optimization (POGO), where a better than 3meter accuracy was demonstrated. Ionospheric errors,tropospheric errors, satellite clock errors, satelliteephemeris errors, and other errors were reducedthrough the use of a centralized sixty state Kalmanfilter.

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measuremenbl Accmte modelhg

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Figure 12. CALCM Precision On-Board GPS Optimization (POGO)Demonstration

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A finat enabling technology for UTA sensors issensor electronics. Figure 13 illustrates the rapidgrowth in electronics for FPAs. The exponentialgrowth in micro processor transistors for FPAs hasabout a three-year lead on the number of pixelsavailable in IR FPAs and about a four-year lag on the

number of pixels available in visible FPAs. There isno sign that the growth rate will slow down. Similarresults also apply to memory ch ips, for example, 256Megabit dynamic ram mem ory chips a re currently indevelopment

1970 1975 1980 1985 1990 1995 2oooYear of lntroductlon

IElectronics for sensors have had rwohftiinary advancemen$ 1Reference:Kozlowski, . J., Impact of SubmicronCMOS n IR FPAS, resented t the

1997Meetingof the IRISSpeciakyGmupon InfraredDetentes,July 1997 sm.IFIIMI

Figure 13. Example of High-Speed, Lightweight Electronics Trend for EO Sensors

4. CONCLUSIONSEnabling capabilities, performance enhancements, andenabling technologies have been identified for UTAsin the year 2007 time &une. The sensor relatedenabling capabilities and performance enhancementsaFiT:

l Multi-spectral, multi-dimensional sensors thatprovide rea1 ime, low FAR ATR and real time,

precision targetingl Flat windows that provide reduced observables

The sensor enabling technologies are:+ Polarized FMCW SAR sensors for detection, ID

and targeting of low observable targets in clutterl Low fkequency, polarized UWB SAR sensors fnr

detection, ID and targeting of low observabletargets in foliage

.

.

l

l

High resotution, multi-spectral FLIR sensors tirID of low observable targets in clutterTunable multi-spectral, three dimensional,temporal LIDAR sensors fbr ID and targeting CElow observable targets in clutterHigh resolution, multi-spectral visible sensorsfor ID of low observable targets in clutterModerate resolution, high contrast passivemmW sensors or ID of low observable targets in

clutterFlat grid windows for reduced observables andlow error slopePhased array antennas for high agility, high datarate comrnAgile, broad band, high accumcy electronicSIGINTPrecision GPS/lNS navigation and targetingHigh speed, light weight electronics

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5. REFERENCESSchneider, Stephen H., Encyclopedia of Climateand Weather, Oxford University Press, 1996.

U.S. Air Force Science Advisory Board SensorsPanel, New World Vistas Air and Space Power tithe Zist Century - Sensors Volume, 1996.

Smart Weapons Specification Guide, U.S. Army -Smart Weapons Management Office, RedstoneArsenal, Alabama, October 1990.

Kozlowski, L. J.,Impact of Submicron CMOS onIR FPAs, presented at the 1997 Meeting of the IRISSpecialty Group on M Detectors, July 1997.

Priessner, 1979