11-1 design of uav systems payloadsc 2002 lm corporation lesson objective - to discuss payloads...

11-1

Design of UAV Systems

Payloadsc 2002 LM Corporation

Lesson objective - to discuss

Payloadsincluding …

• Sensors

• Weapons• Example problem

Expectations - You will understand how to estimate sensor size and performance and understand their impact on overall system performance

11-2



Importance

• UAV systems have little practical value without payloads

- Including UCAVs

• A good understanding of payload design issues and requirements are among the most important issues addressed during UAV pre-concept design

11-3



UAV Payloads

Primary Types :Electro-OpticalRadarCommunications

http://www.fas.org/irp/program/collect/darkstar.htmadar

TUAV

DarkStar

http://www.fas.org/irp/program/collect/tesar.htm PredatorModular Payloads Preferred

11-4



Integrated payloads

11-5



UCAV payloads

http://www.fas.org/man/dod-101/sys/smart

Powered

JSOW

Small

Large

Very Small LOCASS

Air-to-Ground

Glide

UCAV payloads are not covered as a separate subject. See RayAD Chapter 9.5 for overall weapons integration issues and www.fas.org/man/dod-101/sys/dumb/ for data

11-6



UCAV cont’d

Air-to-Air

Possible but not currently planned

11-7



Pre-concept design issues

Power and cooling requirements

Overall sizes

Estimated cost

Sensor type(s)• Wide area• Spot• Targeting• Weather effects

Aperture requirements

Weapon type(s)• Unguided• Platform guided• Off board guided• Self guided

Note : There is no sensor cost data available except for proprietary data from manufacturers

11-8



Sensor resolution

Typically expressed in terms of National Interpretability Rating Scale (NIIRS) or Ground Resolved Distance (GRD)

For more information see http://www.fas.org/irp/imint/niirs.htm

NIIRS GRD (m) Nominal capability (EO)

1 > 9.0 Detect medium sized port 2 4.5 - 9.0 Detect large buildings 3 2.5 - 4.5 Detect trains on tracks 4 1.2 - 2.5 Identify railroad tracks 5 0.75 - 1.2 Identify theater ballistic missile 6 0.40 - 0.75 Identify spare tire on truck 7 0.20 - 0.40 Identify individual rail ties 8 0.10 - 0.20 Identify windshield wiper 9 < 0.1 Identify individual rail spikes



Resolution cont’d

Sensor resolution

0

1

2

3

4

5

6

7

8

9

2 3 4 5 6 7 8 9

NIIRS

2 3 4 5 6 7 8

11-9



Sensor notation - overall

Field of regard (azimuth)

Field of view(azimuth)

Field of view (elevation)

Angular resolution (miliradians)

Target resolution (meters)

Slant range

Target range

11-10



E0/IR sensors

• These cover a range of sensor types from simple TV cameras to sophisticated thermal imaging systems with large focal lengths and zoom range

• All are line of sight systems and typically do not work well in weather

• Despite their weather limitations, EO/IR systems are often preferred because of their high resolution and ease of interpretation

- Even “thermal imagery” is easy to interpret by untrained users

• EO/IR sensors are often mounted in gimbaled “turrets” or balls which protrude into the slip stream

• Some have integrated lasers for range measurement and/or target designation

11-11


Payloadsc 2002 LM Corporation 11-12

Global Hawk Program Update, Kennon Cooksey, Deputy Director, 2/28/2001


Payloadsc 2002 LM Corporation 11-13




EO/IR notation - nonscanning

Field of regard

Line of flight field of view (LFOV)

Max slant range (Rf)Min slant range (Rn)

Single frame - farSingle frame - near

W-swath

L-swath

h

Slant range - nearmechanical limit

Slant range - farfunction(resolution)

Cross flight field of view (XFOV)

11-14



Field of regard

Line of flight field of view (LFOV)

Max slant range (Rf)

Min slant range (Rn)

Single scan -farSingle scan -near

Single frame - farSingle frame - near

Wswath

Lswath

h

Min slant range (Rn)= function(scan time)

Max slant range (Rf)= function (resolution)

min

Cross flight field of view (XFOV)

EO/IR notation - scanning

11-13

R

Hfp = 2EFLTan[FOV/2] = PpNpInflight resolution(IFR) = KD/[d] (cycles/mm) = 1/d’

where KD (EO) ≈ 0.8; KD (IR) ≈ 0.9d’/EFL = GRD’/R or R = GRD’EFLIFRmin = ArcSin(h/Rf)Nonscanning EO/IR: = + FOV Scanning EO/IR: = + SR*t ( > min )

where t = KolLswath/V (Kol < 1 for overlap) Rn = h/Sin()

Wswath = 2RTan[FOV/2] SS coverage = WswathLswath

where SS = single scanCoverage rate = WswathV



Basic equations - EO/IR*

TECHNOLOGY DRIVERSScan rate (SR) in frames/secPixel pitch (Pp) in mm

Typical EO = 5-10 Typical IR = 25

Np = Number of pixels per sideStabilization (mrad)

OPERATIONAL DRIVERSResolution required (GRD or NIIRS)Target coverage rate (sqkm/hr) *Courtesy of Mike I “Indiana” Jones, LM Aero

Max range (Rf)

FOV

Equiv focallength (EFL)

GRD

GRD’ = GRDSin()

11-16

d = 2Pixel pitch (Pp)H

fp

h(alt)



EO/IR example

From Janes UAVs and Targets (USA:Payload)

h = 65Kft = 19.811 Km; V = 343 kts = 176.45 mpsFOV (spot) = 5.1 x 5.2 mrad (0.292 x 0.298 deg)EFL = 1.75 mGRD @ 28Km = NIIRS 6.5 (EO) ≈ 0.44 mPixel pitch = 9, Pixel array = 1024 x 1024Frame rate = 30 fps

Hfp = 10240.000009m = 9.22 mmIFR = 28000/[1.750.440.707] = 51.43 cy/mmTheoretical IFR = 1/[20.009] = 55.55KD = 51.43 /55.55 = 0.93min = ArcSin(h/Rf) = 45 degLswath = 228sin(2.6mrad) = 0.146 Kmt = 146m/176.45mps = 0.827secScans = 0.827s30fps = 24.82 framesAssume Kol = 0.9 = 45 + 24.820.2920.9 = 51.52 degRn = 19.811 km/Sin(51.52) = 25.36 Km

Wswath = 19.811- 25.36*Cos(51.52) = 4.0 Km

Reasons for difference not clear

11-17



• Dual Sensor (IR / daylight) - 3rd gen InSb (3-5 ?m) > Three (3) FOV Optics > 256 x 256 Staring FPA - Daylight color camera with 10X zoom lens • 4-Axis Active Gyro- Stabilization • 6-Axis Passive Vibration Isolation • Power: 210 [W] • Turret - Diameter = 12 [in] (30.5 [cm]) - Height = 14.6 [in] (37 [cm]) - Weight = 47 [lbs] • Electronics Unit - None • Air Vehicle Mounting Unit - Platform Specific • Interface - Discrete / Analog (Pioneer UAV) or RS-422

Typical EO/IR sensor

http://uav.navair.navy.mil/database/matrix.htm

11-18

11-19


Sensorsc 2002 LM Corporation

DESCRIPTION

• Dual Sensor (3-5 micron FLIR & Color TV) • IR camera 640 x 480 InSb Focal Plane Array • 3 FOV optics • Color TV single chip CCD • Zoom lens matched to FLIR • Digital video • 4-Axis Gimbal based on Wescam stabilization technology • Power: +28 volts, 4 amps avg, 10 amps peak, 300 watts (peak) • Turret: • Diameter = 11 inches • Height = 15.5 inches w/mods • Weight = 46 pounds • Mission Interface Unit required • Interface: IEEE 1394 or RS-422

E0/IR example


11-20



DESCRIPTION

• 3-Axis Stabilization • IR detector assembly is a 3-5µm Indium Antinomide • EO/IR/LRF/LI/Spotter Scope payloads available

• Turret Dimensions: 15.1”x 17.55” • Weight: 92lbs • Power: MIL-STD-704D 28VDC, 360W max. • Interfaces: - NTSC/PAL (Video)/RS 170 - 9600 Baud/RS 232/422 - Optional/1553B

E0/IR example


11-21



DESCRIPTION

• IR detector assembly is a 3-5µm Indium Antinomide • EO/IR payloads standard

• Turret Dimensions: 9”x 13.5” • Turret Weight: 26 lbs (total system weight less than 40 lbs) • 2-Axis, 3 Fiber-Optic gyro Stabilization • Power: 28VDC

E0/IR example


11-22



DESCRIPTION

• 2-Axis, 3 Fiber-Optic gyro Stabilization • IR detector assembly is a 3-5µm Indium Antinomide • EO/IR payloads standard • 1.8X Optical IR extender, Low-light monochrome TV or Laser Rangefinder optional Turret Dimensions: 9”x 15.2” Turret Weight: 26 lbs (total system weight less than 42 lbs) Power: 28VDC

E0/IR example


11-23



DESCRIPTION

• 2-Axis, 3 Fiber-Optic gyro Stabilization • IR detector assembly is a 3-5µm Indium Antinomide • EO/IR payloads standard

• Turret Dimensions: 9”x 13.5” • Turret Weight: 26 lbs (total system weight less than 40 lbs) • Power: 28VDC, 450 Watts

E0/IR example


11-24



• Combined IR sensor plus laser (LRD) - 2ND gen FLIR sensor w/ LAP, 3 FOVs, 2X & 4X electronic zoom , and digital video interface - Laser Rangefinder Designator (LRD) - Dual-mode automatic video tracker - Integrated line-of-sight targeting modes (including HELLFIRE) - Imbedded maintenance & alignment features

• Airborne System - Weight < 165 [lbs] - Power - 28 VDC:Nominal 200W - 115 VAC 3 Phase: Nominal 0.9 KVA

• Turret - Diameter = 16.7 [in] (15[in] at base)

- Height = 18.6 [in]

- Weight = 114 [lbs]

• Electronics Unit- Height = 9.25 [in]\

- Width = 13.5 [in]

- Length = 14.75 [in] (incl handles)

- Weight = 48 [lbs]

• Interface(s):

- MIL-STD-1553 data buses

- Discrete / Analog I/O

- RS-170 analog video output

- Digital video output

- Symbology output

IR/Laser example


11-25



• Combined 3 Sensors EO/IR/DPAD • 4-Axis Stabilization (Option for IMU) • In-flight Boresight Mechanism • A Zoom Optics CCD Day TV • Electronic Image Stabilization • Dual Mode automatic Video Tracker • IR detector is a 3-5µm InSb FPA (256 x 256 pixels) • MOSP Payload Family includes: - H-MOSP - For Helicopters - SEA-MOSP: For Shipboard Operation

Dimensions:

Turret Payload Control Logic (PCL) FLIR Electronic Box (FEB)15.0”dia x 19.6”H 9.6”H x 10.7”W x 4.7”L 10.4”H x 10.9”W x 10.6”L70.5 lbs 12.1 lbs 23.3 lbs

Average Power: 28 VDC With DPAD: Average 450W, Max 500W w/o DPAD: Average 310W, Max 420W Interfaces: - Video/RS 170 - Serial Comm/RS 422

E0/IR/Laser example


11-26



DESCRIPTION

• Combined IR/EO/Laser Designator/Eyesafe Laser Range Finder • 4-Axis Stabilization, <20 µrad RMS • 3-5µm Indium Antimonide IR detector, with CO2 Notch Filter • High-resolution CCD TV, matched FOVs to IR • Integrated Boresight Module

• Turret Dimensions: 16.1” D X 19.3” H • Weight: 113lbs • Power: MIL-STD-704D, 800W max. @ 28VDC • Qualifications: MIL-STD-810E and –461D

E0/IR/Laser example


11-27



DESCRIPTION

• RISTA is derived from the Army’s Airborne Standoff Minefield Detection System (ASTAMIDS) program • There are two modes of operation: spotlight and line scanning w/ either mode selectable during flight from the image processing facility (IPF). • Utilizes a 2nd generation IR • Volume: <4900in3 for airborne LRUs • Weight: <145lbs for airborne LRUs <84lbs for ground processor. • Power: 700W avg., 1000W pk. • Cooling: External Ambient Air • Interfaces: - Video/Rs 170 - RS 232/485

E0/IR/Laser example


11-28



DESCRIPTION

• 3-Axis Stabilization • IR detector assembly is 8-12µm 4X4 MCT w/TDI • EO/IR/LRF/LI payloads available

• Turret Dimensions: 15.1”x 17.55” • Weight: 88lbs (w/CCD or LRF) • Power: MIL-STD-704D 28VDC, 360W max

E0/IR/Laser example




DESCRIPTION

• Combined EO/IR/LD/LRF (with eye safe modes)/Tracker • Options: LST and Low light CCD • 20.5 in. Diameter Turret / 24 in. height • Target Weight - RFI = 206 & AH-1Z = 277 • Power: 1.6 kW • Interfaces: - RS 422 - IEEE 1394 • Internal Volume: 1 ft3

E0/IR/Laser example


11-29

11-30



Global Hawk EO/IR

11-31



E0/IR sizing

EO/IR Power

0

400

800

1200

1600

5 10 15 20 25

Turret diameter (in)

Wa

tts (

pe

ak

)

EO/IR Turret size

10

15

20

25

5 10 15 20 25

Diameter (in)

He

igh

t (i

n)

EO/IR Weight

0

50

100

150

200

250

5 10 15 20 25

Turret diameter (in)

We

igh

t (l

b)

Global Hawk EO/IR Sensor

“Small” UAVs≈ 50 ppcf

≈ 14 ppcf

11-32



RF sensors

• These cover a range of sensor types from simple airborne weather radar to sophisticated multi-mode electronically scanned radar systems

• The two most widely used are synthetic aperture radar (SAR) and moving target indicators (MTI) and combinations thereof (SAR/MTI)

• RF sensors are generally considered “all weather” systems but their performance can be significantly degraded by rain or moisture

• One disadvantage of RF sensors is the interpretability of their “imagery”

- A SAR “image” may look like a picture but it isn’t- Shadowing, scattering and multipath are problems

• Most RF antennae scan mechanically, more modern (and expensive) ones scan electronically

11-33




11-34



Sensor notation - SAR

Field of regard

Max range

Min range

W-swath

L-swath

h Slant range - min Slant range - max

Wide area search mode- near real time

Squint angle < 60 degSpot mode - long dwell time

11-35



Wide area coverage

Straight line coverageArea = SwathSpeedTime

Search distance = Area/Swath

Search pattern coverageKArea = SwathSpeedTime= SwathLEDRFcr/RFloTypical factor (K) = 1.3?

11-36



Spot area coverage

GH example -1900 spots per day

Average dwell time = 24*3600/1900 = 45.5 sec/spot

Spot area coverage = 1900*4 = 7600 sqkm/day

vs. 138,000 sqkm/day search

(4/98)

Graphic from page 54 (grid added)

11-37



http://www.fas.org/irp/program/collect/tesar.htm

Predator SAR

11-38



http://www.fas.org/irp/program/collect/tesar.htm

Predator cont’d

11-39



DESCRIPTION

• Operates in SAR and MTI modes • Coordinates of each map center are provided within 25 meters CEP • Provides for operation in a strip, and spot map modes MTBF >900hrs

Performance/Specifications Hardware

RF Frequency Ku-Band Weight 74.9kg/165lbs Power 1050W Volume 0.12 m3/4.15ft3 Cooling Ambient Air MTBF >900hrs Ground Speed 50-90 kts Altitude 7620m/25,000ft

Predator radar


11-40



A Lightweight, High Performance SAR, Designed and Built for UAV Platforms - Two stripmap or search modes - Spotlight Mode - Ground moving target indicator (GMTI) - Coherent change detection (CCD) - Ku band operation - 0.3 m resolution in stripmap mode - 0.1 m resolution in spotlight mode - 30 km range in weather (0.3 res) - Weight < 115 [lbs] - Power < 1200 W total • Digital imagery output available in NITF format and NATO standard format • Power - 500 Watts

• Antenna Assembly - 19 in. diameter radome - Reflector antenna - Three-axis gimbal - Motion measurement hardware (IMU & GPS) - 320 W TWT - LNA • Radar Electronics Assembly - Height = 10.75 [in] - Width = 14.88 [in] - Length = 21.5 [in] - VME chassis - slots available • Interface(s): - NTSC video link/RS 170 - Digital data link for full resolution/RS485 - GA-ASI ground control station link • Data Transfer Rates - Spotlight Mode/3.2 mbsec - Strip mode/ 10m

Other SAR




DESCRIPTION• Uses heritage from all of Europe’s space SAR projects (ERS-1, ERS-2, ASAR).• Provides a modular, flexible and expandable payload system for all types of UAV w/ a payload capacity of greater than 35kg. • Capable of multi-payload control.• Can be adapted to use at L, C, X, or Ku-Band operation

Parameter Value UnitsRADAR Frequency 9650 MHzBandwidth 270 MHzTX. Power 200 WMin PRF 275 HzMax PRF 6500 HzAntenna Length 41 cmAntenna Height 21 cm

Parameter Mass (kg) DC Powe r (W)Controller 15 121RF Equipment 6 52Power Conditioner 2 31Transmit Amplifier 1 2Receive Antenna 0.1 2Antenna 1 0Antenna Platform 10.1 31Harness 1 0

More SAR


11-41

11-42



Global Hawk SAR/MTI

11-43



DESCRIPTION

• Unit will provide both SAR and MTI modes. • SAR mode provides both strip map and spot images at resolutions from 0.1 to 1.0 meters at ranges from 3 to 12 km. • MTI mode will detect a 10m2 target at 14 km with a PD of 0.75 • False alarm rate less than 2 per minute in 4mm/hr rain. • Weight: 63 lbs Interfaces: -RS 422 • Power: Surge - System Start up with fans and all electronics powering up: 616 W Constant - All systems operating except transmitter 380W Peak - All systems operating and transmitting: 476W

NOTES

• Unit is being developed for the US Army. • SAR is designed to be low cost with predicted recurring cost per payload (for the 10th unit in a lot of 10) is less than $500

TUAV SAR/MTI


K?

11-44



DESCRIPTION

• SeaVue Has Nine Operating Modes: Standby, Test, Search1, Search2, Weather, ISAR, SAR, DBS, MTI

• Hardware: - Rcv_Exc_Sync_Processor - Transmitter (X-Band) - Antenna System Weight: 200-lbs.

• Platforms: - Helicopters - Large & Small MPA - Ships - Land Based

Maritime Surveillance & Tracking• ASuW, OTH-T, ASST• Search and Rescue Ship and Overland Imaging• Activity Detection

Multimode radar example




RF sensor sizing

Global Hawk

UAV RF Sensors

0

150

300

450

600

750

0 3 6 9 12 15

Volume (cuft)

We

igh

t (l

bs)

SARMTI

UAV RF Sensors

0

1500

3000

4500

6000

0 150 300 450 600 750

Weight (lb)

Po

we

r (W

)

SARMTI

≈ 43 ppcf

≈ 40 ppcf

SAR sizing

0

2000

4000

6000

0 50 100 150 200

Max Range (km)

11-45



Sensor bandwidth

Sensor bandwidth requirements trace directly to sensor coverage requirements per unit time

SAR image at expanded scale showing pixel detail and gray scale level

Example - Global hawk SAR imaging data

11-46



• Global Hawk SAR example - 138,000 sqkm/day area search area at 1m resolution (from Lesson 9)

138,000 km^2/day @ 1m resolution = (138000 sqkm)*(10^6 sqm/sqkm)/(24*3600 sec/day)= 1,597,222 resolution cells per second

- At an 8 level gray scale, 1 resolution cell requires 8 bits of data or 12.8 Mbps

- With 4:1 compression, data rate reduces to 3.2 Mbps• Spot image example - 1900, 0.3 m resolution 2 Km x 2

Km SAP spot images per day, an equivalent data rate of 2.0 Mbps

• Ground moving target indicator (GMTI) example - search rate of 15,000 sq. Km/min at 10 m resolution, an implied bandwidth of about 5Mbps

Bandwidth calculation

11-47

11-48

ExpectationsDesign of UAV Systems


You should now understand

• Basic sensor types

• System design and operational considerations•

• Basic sizing considerations

• Sensor bandwidth requirements

• How to make an initial estimate of size, weight and power

• Where to go for more information

11-49



Example problem

• Five medium UAVs, four provide wide area search, a fifth provides positive target identification- WAS range required (95km) not a challenge

• Only one UAV responds to target ID requests• No need to switch roles, simplifies ConOps• No need for frequent climbs and descents

• Communications distances reasonable (158nm & 212 nm)

• Speed requirement = 280 kts • Air vehicle operating altitude differences reasonable • What sensors are required?• How big are they and how much power is required?

100 nm

200 nm x 200 nm

158 nm

27.4 Kft

10 Kft27.4 Kft 27.4 Kft

212 nm

11-50



“Project” sensors

SAR (Ground moving target indication = GMTI, Wide area search = WAS, Spot mode = Spot)• Long range (Spot-WAS-GMTI)

• 0.3-1.0-10m resolution @ 20-200 Km, 6400W, 640 lbm• Medium range (Spot-WAS -GMTI)

• 0.2-1m -10m resolution @ 5-50 Km, 1160W, 168 lbm• Short range (Spot-WAS -GMTI)

• 0.1-1m -10m resolution @ 3-12 Km, 476W, 63 lbmEO/IR

• Global Hawk Scanning Type (Spot-WAS) • 0.5-0.75m resolution @ 28 Km, 582W, 220 lbm

• Turret Type I @ 12”D (Spot-WAS) • 0.15m-3.2m resolution @ 3-8 Km, 300W, 50 lbm

• Turret Type II @ 15”D (Spot-WAS) • 0.3-0.64m resolution @ 8 Km, 700W, 100 lbm

See – ASE261.ProjectSensors.xls

11-51



• If a UAV loiters over a fixed point in the middle of a square surveillance area, it can meet the 80% coverage, 2 minute moving target detection wide area surveillance (WAS) requirements if1. It makes a turn every 2 minutes (assuming a nominal 45 degree SAR field of regard)

- And the image processing plus transmit time is held to 30 seconds or less

2. The SAR range is slightly larger than ½ the width of the surveillance area- Area of circlesquare = /4

= 0.7853. It has a 100% detection rate

Search considerations - review

Target

101 nm

200 nm x 200 nm

Target

Min range effects ignored

11-52



Min range coverage effect

Rmin = RmaxTan()/Tan()

hmin =RmaxTan()

Nominal min = 5Nominal max = 60Nominal FOR = 45

Therefore, nominal GMTI Area := (/4)[Rmax^2-Rmin^2] == (/4)(Rmax^2){1-[Tan()/Tan()]^2} 0.997(/4)(Rmax^2)

Rmax

Bottom line – don’t worry about the min range GMTI hole under the platform

11-53



SAR sizing considerations

A number of factors affect SAR range (minimum and maximum) and resolution- Power (how much RF energy is reflected from the target)

- Even though transmitted power required vs. radar range is typically expressed as a 4th power relationship, our parametric data (based on total input power required) shows a nominal linear relationship

- Geometry (minimum and maximum depression angles)- Absolute minimum angle defined by the radar horizon- Typical minimum “look down” angle 5-10 degrees- Typical maximum “look down” angle about 60 degrees

- Dwell time (how long energy stays on the target)- Function of platform speed and/or antennae pointing

- Signal processing timeTo keep things simple, we resize using only the range-power parametric and geometry (ignoring curvature)

11-54



Long Range SAR Profile

0

10

20

30

40

50

60

70

0 100 200 300

Range (km)

Alt

itu

de

(Kft

)

5.6 deg

5 deg

Max range(from spreadsheet)

Min range(from spreadsheet)

44.7 deg

20.8 deg

SAR geometry

This project SAR is operating near the limit of minimum acceptable grazing angle• Max range grazing angle = 5.7 vs. minimum 5 degrees

Note - earth curvature effects have been ignored

11-55



SAR geometry (cont’d)

With additional power these SARs could increase WAS range to 52 - 87 Km• After that increased altitude search altitude is required

Other SAR Profiles

0

10

20

30

0 25 50 75

Range (km)

Alt

itu

de

(Kft

)Medium Range SAR

Short Range SAR8.7 deg

20.8 degMax range at 5 degree lookdown = 52 - 87 km

17 –27 deg

This plot also ignores earth curvature effects

11-56



• We have a threshold requirement for positive (visual image) target identification (ID) 80% of the time

• To design our baseline for the threshold requirement• We have to be able to operate at or below 10 Kft for 30% of the target identifications

• 50% of the time we can stay at altitude and 20% of the time we won’t see a target (unless we image at <= 5 Kft)

• This places 10Kft efficient cruise, loiter and climb and descent rate requirements on the air vehicle

Positive ID considerations

Cloud ceiling/visibility Clear day, unrestricted 10Kft ceiling, 10 nm 5Kft ceiling, 5 nm 1Kft ceiling, 1nm

Percent occurrence 50%30%15%05%

Atmospheric conditions (customer defined)

11-57



• Some but not all wide area search, ground moving target requirements can be satisfied by spreadsheet ASE261.Project Sensors.xls medium range SAR• Weight = 168 lbm• Volume = 4.15 cuft• Power req’d = 1160 W

• We solve the problem by using parametric data to resize the SAR • Power req’d = 3000 W• Weight = 350 lbm• Volume = 8 cuft

• The under weather, target identification requirement is satisfied by EO/IR turret type 2 • GRD = 0.3 @ 8 km • Diameter = 15 in• Weight = 100 lbm• Volume = 1 cuft

• Resolution = 10m• Range = 50km• Field of regard = 45

•Power req’d = 700 W

Sensor payloads

95km req’d

We assume resolution and field of regard are unchanged

Or = 0.5m at 13.3 km (from basic optics)

11-58



• All systems on an air vehicle have installation weight and volume penalties (to be covered in detail later)• We will assume typical installation at 130% of dry

uninstalled weight• We will make this assumption for all installed items

(mechanical systems, avionics, engines, etc.)• Installed volume is estimated by allowing space

around periphery, assume 10% on each dimension • Installed volume = 1.33 uninstalled volume

• For frequently removed items or those requiring air cooling, we will add 25%• Installed volume = 1.95 uninstalled volume• Our payloads and data links will be installed this way

• Installed weights and volumes as follows:• EO/IR = 130 lbm @ 1.95 cuft• SAR = 455 lbm @ 15.6 cuft• Communications (each) = 67.5 lbm @ 4.5 cuft

Installation considerations

Total = 720 lbm @ 26.55 cuft

11-59



• It is important to maintain an up to date list of requirements as they are defined or developed

Defined requirements (from the customer)• Continuous day/night/all weather surveillance of 200nm

x 200nm operations area 100 nm from base • Detect 10 sqm moving targets (goal = 100%, threshold

= 80%), transmit 10m resolution GMTI data in 2 min.• Provide 0.5 m resolution visual image of spot targets

(goal = 100%, threshold = 80%) in 15 min.• Operate from base with 3000ft paved runway

Cloud ceiling/visibility Clear day, unrestricted 10Kft ceiling, 10 nm 5Kft ceiling, 5 nm 1Kft ceiling, 1nm

Percent occurrence 50%30%15%05%

Atmospheric conditions (customer defined)

Requirement summary

1 ID PER HR

11-60



Derived requirements (from our assumptions or studies)• System element

• Maintain continuous WAS/GMTI coverage at all times• One target recognition assignment at a time• Assume uniform area distribution of targets• Communications LOS range to airborne relay = 158 nm• LOS range from relay to surveillance UAV = 212 nm

• Air vehicle element• Day/night/all weather operations, 100% availability• Takeoff and land from 3000 ft paved runway• Cruise/loiter altitudes = 10 – 27.4Kft• Loiter location = 158 nm (min) – 255 nm (max)• Loiter pattern – 2 minute turn• Dash performance =141 nm @ 282 kts @10 Kft• Payload weight and volume = 720 lbm @ 26.55 cuft• Payload power required = 4700 W

Derived requirements

11-61



• Payload element• Installed weight/volume/power 720lbm/26.55 cuft/4700W• SAR/GMTI

• Range/FOR /resolution/speed = 95 km/45/10m/2mps• Uninstalled weight/volume/power 350lbm/8cuft/3000W

• EO/IR • Type/range/resolution = Turret/13.3 km/0.5m• Uninstalled weight/volume/power 100lbm/1cuft/700W

• Communications • Range/type = 212nm/air vehicle and payload C2I

• Uninstalled weight/volume/power 52lbm/2.3cuft/500W• Range/type = 158nm/communication relay

• Uninstalled weight/volume/power 52lbm/2.3cuft/500W

Derived requirements

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Reading assignment

Raymer, Aircraft Design - A Conceptual Approach

Chapter 18 - Cost analysis

• Chapter 18.1 : Introduction• Chapter 18.2 : Life cycle cost• Chapter 18.3 : Cost estimating methods• Chapter 18.4 : RDT&E and production costs• Chapter 18.5 : Operations and maintenance costs• Chapter 18.6 : Cost measures of merit

Total : 15 pages

Note - Raymer is a reference book. It is not necessary to memorize or derive any of the equations. Read the sections over for general understanding of the concepts.

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Homework

Assess sensor requirements for your project and define a sensor suite that you think will work(1) Size a sensor suite that meets requirements

- Uninstalled weight, volume and power(2) Calculate installed weights and volumes.

- Use nominal installation factors(3) Calculate total weight & volume power required(4) Document your derived requirements

Submit your homework via Email to Egbert by COB next Thursday. Document all calculations

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Intermission

11-1 design of uav systems payloadsc 2002 lm corporation lesson objective - to discuss payloads...

Documents

range of sensor types

field of regardline

sensor resolutiontypically

sensor notation overall11

eoir systems

sensor size

importanceuav systems

uav payloadsprimary