TAWS Visual Slant Range Detection Assessment 2 Feb 04

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TAWS Visual Slant Range Detection Assessment2
Feb 04

• 1LT Joseph D. Coughlin
• MR3570
• Winter 2004

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Introduction

• Background/Goals/Assumptions
• Data Collection (Dates/Times/Locations)
• Collection Methods
• Observed Output
• TAWS Input
• TAWS Output
• Conclusion/Errors
• Future Studies

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Background/Goals/Assumptions

• Compare TAWS Visual Slant Range Detection
  capability with observed data
• Prove TAWS effectiveness at multiple altitudes
  and multiple headings
• Assumptions
• Used TV sensor instead of VIS sensor
• TAWS target much smaller than actual target
• Sortie vehicle difference

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Data Collection

• CIRPAS Twin Otter Research Aircraft
• Sfc and FL Data collected every second from
  2115z-2305z on 2 Feb 04
• RV Point Sur
• Sfc Data collected every 20 seconds from
  2115z-2305z on 2 Feb 04
• Observer Max Detection Determinations
• Done by both pilots and myself during each leg of
  the flight duration. Total of 15 observations.

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Data Collection
My Observation Portal
Most used aircraft data - RH - Mixing Ratio
Most used ship data - Solar Rad. - RH - Ts and
SST
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Location
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Flight Route
4 round trips to the W
RV Point Sur
3 round trips to the SW
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Collection Methods

• Max Detection Range (MDR) done by visible
  confirmation of lost or gained sight of target.
  At that point, the pilots give exact distance
  away from ship via on-screen display
• Going away from ship I determined MDR, which was
  somewhat inaccurate
• Spherical portal fogs and is better for looking
  down than back
• Low slant angle, thus, cloud background early
• Heading back at ship, pilots determined MDR
• Two sets of eyes
• Better viewing display

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Observed Output
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Observed Output
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Observed Output
-SHRA anomaly with unrestricted vis, although
temporarily increased moisture
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TAWS Input

• Target/Background Properties
• Sortie Properties
• Meteorological Data
• Real World would be forecast data
• We used observed data for better accuracy

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TAWS Input Target/Background
Closest assumption provided by TAWS program.
Used because of its high reflectivity.
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TAWS Input Sortie Properties
Closest assumption provided by TAWS program.
Used because of its relatively low speed, low
altitude and fairly high reflectivity.
TV Sensor. TAWS does not have VIS capability.
Very similar though, with ? in the VIS and NIR.
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TAWS Wx Data
Ranges are 24-hr highs and lows over the target
Some parameters are negligible due to low FL and
because looking in the VIS
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TAWS Wx Data
Very in-depth temporal parameters, more of a
factor for IR sensors
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Why Tactical Decision Aids?
Sortie success with IR Sensor
100
Random
90
Sorties
80
Time of Day
70
Effects Only
60
50 Forecast
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Sortie Success Rate ()
75
40
30
90
20
10
100
0
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TAWS Output
Just solar effects would say less radiation over
time, therefore, slightly degraded vis range
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TAWS Output
TAWS Derived Data
Actual Obs
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TAWS Output
TAWS Derived Data
Actual Obs
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TAWS Output
TAWS Derived Data
Actual Obs
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TAWS Output
TAWS Derived Data
Actual Obs
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TAWS Output
Both are TAWS Derived Data
Actual Obs
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TAWS Output
TAWS Derived Data
Actual Obs
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TAWS Output
TAWS Derived Data
Actual Obs
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TAWS Output
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TAWS Output
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Conclusions/Errors

• Similar trend in rising MDR during late
  afternoon, due to improving Met cond.s
• All altitudes showed similar trends
• Westerly flight path had more similar slope trend
• Due to less direct incoming sunlight, which TV
  sensor didnt account for as much
• Observed MDR was only 72.5 the distance TAWS
  derived
• Errors
• Observer error in determining exact moment of
  gain or loss
• TAWS assumptions
• TV Sensor vs. VIS
• Improper Target Sortie vehicles
• Wx inputs not as microscale
• With these errors I still feel that the TAWS
  derived data was quite accurate and was a good
  representation of the environment that was input

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Further Study

• Less assumptions with TAWS
• Forward-looking IR
• NVGs
• Use a predetermined TAWS target
• EOSTAR
• If Vis sensor is a must

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Thanks

• CIRPAS
• Haf Jonsson
• NPS
• Prof Wash
• Prof Guest
• Prof Davidson
• Dr Goroch