1 White and Green Phosphor NVD Comparative Assessment Army - - PowerPoint PPT Presentation

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White and Green Phosphor NVD Comparative Assessment

Army Aviation Test Evaluation Section

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Background

• 2016, aircrew from 6 Avn Regt noted that customers
• perating a type of Night Vision Devices (NVD) with a white

phosphorous image were better able to identify obstacles than aircrew operating current AN/AVS-9 NVD with green Phosphorous Image.

• Performance discrepancy was reported via a Statement of

Operational Requirement from 6 Avn Regt

• DACM tasked AATES to investigate.

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Image: Google

Test Objectives

• Comparatively assess L3 M949 WP and GP NVD to identify if changes

in NVD image colouration afforded:

• Improved handling qualities
• Reduced crew workload, or
• Increased safety of flight for S70A-9 operations.

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SUT Description

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• L-3 Warrior Systems AN/AVS-9 M949 White Phosphor Binocular

Assembly Night Vision Device (Part No. 245081-044)

• L-3 Warrior Systems AN/AVS-9 M949 Green Phosphor Binocular

Assembly Night Vision Device (Part No. 245081-046)

• Third Generation IIT
• Designed with a FOM of 2376
• Auto-gating functionality
• Class B filter

SUT Description

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• Green Phosphor was traditionally used in IIT because the eye is more

sensitive to green light (550nm)

• Early NVD had low luminance, therefore they required a colour that

the eye was most receptive to.

• Fatigue, object detail etc
• Low Photopic Region / Scotopic – Good for dark adaptation
• Monochrome – purple eye – chromatic adaptation, less sensitive to

the green, looks red or blue

Test Aircraft

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• Fleet standard S-70A-9 Black Hawk Configuration 1 or 2 Helicopter
• Fitted with doors, ballistic protection, Fast Roping and Rappelling

Device (FFRD), Hook and Hoist

• Used a DGPS fitted under deviation for as instrumentation

Test Inputs

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• AASPO and ALSMU
• Technical Comparison
• IAM (AVMED)
• Physiological Advice
• DSTG
• Laboratory Performance Testing
• Luminance Gain
• Halo Size
• Device Modulation Transfer Function
• Device Spectral Power Distribution

Test Methodology

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• Ground Trial (Phase 1)
• System To aircraft compatibility performance assessment was conducted at

Woomera Range Facility on 25 Sep 18

• Internal Lighting Compatibility
• External Lighting Compatibility
• Infinity Testing

Test Methodology

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• Flight Trial (Phase 2) –
• Category 2 Flight Test conducted under a MPTF approved by SO1 T&E and

DOSA-FT.

• 4 Specific Illumination Levels Targeted
• 2 x QTP’s
• MTE’s
• Circuit Area Operations
• Confined Area Operations
• High Light Environment
• Dust Operations
• Coastal Operations
• Flare Serials
• Formation
• ADS-33 Tasks
• IAP to Circling Landing
• Range Distance Evaluation
• Workup
• Area Reconnaissance
• Currency for data quality

Test Methodology

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• Quantitative
• Cooper Harper Handling Qualities
• ADS-33 Tasks or MTE with defined desired and adequate criteria
• UCE Ratings
• Qualitative
• Subjective Ratings
• Multiple Evolutions

Test Instrumentation

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• PFPS SLAT data (Hoffman ANV-401B Night Sky Luminance meter)
• Hoffman LM-33-400 Night Sky Simulation System
• DGPS
• Flight Data Recorder information
• Laser Range Finder
• Multiple cameras including Go Pro and Apple Iphone with NVD

adaptor Bracket

• Range resolution chart (3m x 3m)

Test Limitations

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• IAM / DSTG (availability of OEM data)
• Estimated Illumination Levels (planned operations)
• Application of scientific method (breadth vs. sample size)
• Prolonged brownout testing not conducted
• Still photography (representative not definitive)
• Test Aircrew and Aircrewman (8 – exposure and data)
• Widely available ‘data’ lacked scientific method and military data was

unavailable (from Overseas)

Test Environment And Conditions

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• Ground Test Trial (Phase 1) was conducted from Woomera Range

Facility 25 Sep 18

• Flight Test Trial was conducted from Luscombe Airfield, Holsworthy

Barracks over the period 14 Nov – 06 Dec 18

• Illumination

Night Level (NL) Definition Night Sky Illumination (lux) 1 Twilight Civil and Nautical Twilight 40 to <1000 2 Light Full Moon 10 to <40 3 Intermediate < 1/2 moon 2 to <10 4 Very Dark Starlight or Overcast < 2

Results

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DSTG Testing

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• Luminance, Gain and MTF, GP and WP showed equivalent results.
• Device Spectral Power Distribution
• The green and white L3 goggles are identical in photopic range emission

(400-700 nm)

• WP are 3.41 times larger in the melanopic range

DSTG Testing

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• Photopic and Melanopic Sensitivity Curve
• Melanopic Receptors are only recently discovered and are sensitive to

blue light (380-580nm)

• Melanopic Receptors are stimulated it inhibits melatonin production

which is the hormone responsible for drowsiness.

• Pilots using WP NVDs could experience an increase in level alertness

and potentially better cognitive performance than those using GP NVD.

IAM Testing

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• Dark Adaptation
• Conclusion: Any uncharacterised effects of dark adaptation do not

impose any risk to current 2 pilot operations.

• Recommendation: No change to current operations.

Reporting Terms

19 TERMS USED IN CONCLUSIONS AND RECOMMENDATIONS

CONCLUSION DESCRIPTION OF DEFICIENCY RECOMMENDATION TERMINOLOGY RECOMMENDATION LEVEL UNACCEPTABLE Prevents weapon system performing

• perational task or liable to cause

accidents – restrictions needed to prevent occurrence are considered intolerable. Something must be done. Essential UNSATISFACTOR Y Restricts aircraft’s operational capability, or is liable to cause accidents unless significant restrictions are imposed. Something should be done. Highly Desirable UNDESIRABLE Could be improved to make a safer or more capable aircraft. Something could / should be done. Desirable SATISFACTORY Satisfactory without improvement. No action. N/A ENHANCING CHARACTERISTIC Characteristic which improves the

• perational capability or safety of the

design Should be incorporated in future designs Desirable

Confined Area Approach

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• Objective. Compare task performance and workload conducting CA

approaches

• Conclusion: L3 M949 WP NVD reduced workload and improved

accuracy when conducting CA approaches and were an ENHANCING FEATURE.

• Recommendation: The acquisition of WP M949 NVD for confined area

evolutions should be investigated (Desirable).

Highlight Environment

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• Objective: Comparative assessment of GP and WP NVD in Highlight

Environment.

Highlight Environment

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• Conclusion: Confined Area approaches in highlight environments were

conducted with reduced risk of aircraft or personnel damage using L3 M949 WP NVD and were an ENHANCING FEATURE.

• Recommendation: The acquisition of WP NVD for highlight evolutions

should be investigated. (Desirable).

Dust Approaches

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• Objective: Comparative assessment of GP and WP NVD during dust

approaches

• Conclusion: Dust approaches were conducted with reduced risk to

aircraft or personnel damage on landing using L3 M949 WP NVD.

• Recommendation: The acquisition of WP NVD for dust evolutions

should be investigated. (Desirable).

Formation

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• Objective: Comparative assessment of GP and WP NVD during formation
• Conclusion: Formation flight was conducted with greater precision and

reduced workload using GP M949 and were an ENHANCING FEATURE.

• Recommendation: The acquisition of GP M949 NVD for formation

evolutions should be investigated (Desirable).

Slope Landing & Pirouette

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• Objective: Comparative to L3 M949 WP and AN/AVS-9 NVD, slope Landings

were conducted

• Conclusion: Comparative to L3 M949 WP and AN/AVS-9 NVD, slope Landings

were conducted with reduced workload and improved accuracy on GP L3 M949 NVD and were an ENHANCING FEATURE

• Recommendation: The acquisition of GP L3 M949 NVD for slope landing

evolutions should be investigated (Desirable).

Range Resolution Board

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• Objective: Maximum range a pilot could accurately resolve elements of a

spatial resolution board.

Range Resolution Board

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• Conclusion: There was no significant difference in range distance identified

between L3 M949 WP or GP NVD.

• Recommendation: The acquisition of L3 M949 NVD WP or GP for target

range evolutions should be investigated (Desirable).

200 400 600 800 1000 1200 GP WP GP WP GP WP GP WP GP WP GP WP GP WP GP WP QTP 1 QTP 2 QTP 1 QTP 2 QTP 1 QTP 2 QTP 1 QTP 2 100% Illum Twilight 25% Illum Moon 0% Illum

Range (m)

Inflight Range Resolution - All Illuminations

YSHW 21 Nov 18 100% Illum QNH 999, 21°C, Vis > 10 km, Ovcst FL150 YSHW 27 Nov 18 Twilight & 1/4 Moon QNH 1005, 18°C, Vis > 10 km, Ovcst FL150 YSHW 05 Dec 18 0% Illum QNH 1024, 22°C, Vis > 10 km, Ovcst 3000' 56H LH 04367 06705 80 kts G/S, 135°, 300 ft AGL, Criteria Earlier of 3 evenly spaced vertical or horizontal bars.

High Tensile Power Lines

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• Objective: Comparative assessment of maximum detection, recognition,

identification range of WP and GP.

• Conclusion: The L3 M949 WP NVD were superior in detecting, recognising and

identifying high tension power lines and was an ENHANCING FEATURE .

• Recommendation: The acquisition of WP L3 M949 NVD for improved obstacle

identification and avoidance should be investigated (Desirable).

266m or 6 Secs

Subjective Visual Comfort

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• Subjective Observations
• Black and White fashioned a more pleasant image comparative to green

monochrome.

• Subjectively improved contrast
• Black to white potentially allowed for faster interpretation of information.

Summary

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• L3 M949 WP and GP NVD were comparatively assessed to identify if

advances in NVD technology afforded improved handling qualities, reduced crew workload or increased safety of flight for S70A-9

• perations.
• On 15 occasions the performance of WP was identified as an

enhancing feature.

• On 10 occasions the performance of GP was identified as an

enhancing feature.

• WP was notably superior in Highlight and Dust Environments
• GP was notably superior in high gain close to ground tasks and

formation.

• WP was the subjective preference by both pilots and ACMN

Recommendation

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• L3 M949 WP NVD showed good potential as a replacement type of

NVD and was assessed as superior to L3 M949 GP NVD.

• WP should be considered as an option for future procurement on all

platform types.

• Fatigue and dark adaption requires further investigation.

Questions

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