torpedo proximity scoring system (tpss) · 2012. 1. 6. · the torpedo proximity scoring system...
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Torpedo Proximity Scoring System (TPSS)
Prepared For: International Test and Evaluation Association
Prepared By: Clarence Ching, (NUWC/KPT)Gregory A. Babich (ARL/PSU)Bruce J. Frei (ARL/PSU)Bruce T. Einfalt (ARL/PSU)
21 November 2010
Outline
• Background• Development Process• System Design• System Components• Summary• Acknowledgements
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The Torpedo Proximity Scoring System (TPSS) was developed to provide a previously non-existent Test and Evaluation (T&E) capability to Commander Operational Test and Evaluation Force (COTF) for operational evaluation of an Anti-Torpedo-Torpedo (ATT).
The purpose of TPSS is to provide the ability to accurately measure the Closest Point of Approach (CPA) of an ATT as it engages a torpedo emulator during operational testing.
Current U.S. Navy tracking ranges do not currently have the ability to accurately measure the ATT’s CPA nor do those tracking ranges provide all the acoustic environments required for ATT operational testing.
Background
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Develop a torpedo-based CPA measurement system that willprovide the ability to accurately measure the CPA of an ATT as itengages the torpedo emulator during operational testing.
Design the system to accommodate additional capabilities toenable advanced threat emulation
Utilize open architecture and COTS hardware
Build six Torpedo Proximity Scoring System (TPSS) units
Firewall activities from ATT Developmental Testing efforts
Background:Objectives
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NUWC/KPT—ARL/PSU development process provides quick reaction capability (QRC) to support current and future DoD needs
Close attention paid to end-user’s needsRapid prototypingDeliver systems for use in operational environments
Work closely with end-user throughout development processWelcome and encourage end-user(s) to participate in development processCan generally make changes on the fly throughout the development process with minimal impact to schedule/budget
Emphasize strong engineering standardsStreamlined design reviews (SRR, PDR, CDR, etc.)Open architecture design with COTS hardware Extensive, rigorous testing (deck, acoustic tank, test ranges)
Development Process
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2005April, kickoff and system optionsAugust, system requirements review (SRR)
2006April, system design review (SDR)June, TPSS self-noise test at seaNovember, first use of TPSS with ATT
2007ATT vs. TPSS throughout 2007May, all 6 TPSS units and spares deliveredJuly, closeout briefing with sponsor
2008—2010Three years of ATT vs. TPSS
Development Process:Timeline
20 months from kickoff to use against ATT
28 months from kickoff to Government accep-tance of 6 TPSS units
Nearly 100 shots since 2006
15 months from kickoff to at-sea shakeout
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s1
s2
s3
TIME
RA
NG
E
r1
r2
r3
Discrete Range to ATT
Continuous Range to ATT
Timestamp Approach
r = c·∆t
System Design:Overview
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r = c·∆t rm = (c+ec)·(∆t+e∆t)
= c·∆t + c·e∆t + ec·∆t + e∆t·ec = r + c·e∆t + ec·∆t + e∆t·ec|rm- r| = |r - r + c·e∆t + ec·∆t + e∆t·ec| = |c·e∆t + ec·∆t + e∆t·ec|
= |c·e∆t + (c/c)·ec·∆t + e∆t·ec| = |c·e∆t + r·ec/c + e∆t·ec| ≈ |c·e∆t + r·ec/c| ≤ c·|e∆t| + r·|ec|/c
r is the true range to the ATTrm is the measured range to ATTc is the true speed of soundec is the error term accounting an erroneous speed of sound∆t = true receive time - true transmit time e∆t is the error term accounting for an erroneous time delay
System Design:Error Analysis
Major source of range measurement error is e∆t
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GPS
Disciplining(Connected to GPS)
IRIG-B
. . . . . . . . . . . . . . . . .
Minimal timestamp drift over duration of run
GPSMinimal timestamp drift when compared to GPS time
Time
Power-up Run CompleteLaunch
Start Recording
Recording
Stop Recording
System Design:Timestamp
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System Design:Operations
Data Recording
Data Analysis
Acoustic data and timing info recordedData reordered in MATLAB MAT filesOpen-loop geometry or closed-loop tactics
Analysis softwareEvaluationDocument results
Prepare vehicle for deployment
Record acoustic data during run
Download data from TPSS (data extraction), acquire signal transmit times from ATT, and acquire range data (when available) to augment analysis
Using analysis software, determine ATT’s CPA based on acoustic data
Document results
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System Components:Overview
Hydrophones Record System Analysis Computer
8 hydrophones total
2 hydrophones in nose
2 EFOV shells
3 hydrophones per EFOV shell
Housed in nose
IRIG card w/rubidium clock
COTS processors & drives
COTS A/Ds
Acoustic data recorded in MATLAB MAT files
PC
MATLAB
PSU/ARL-developed MATLAB code
CPA algorithms and GUI
Pre-launch deck checks
Extended Field of View (EFOV)
ShellsRecord System
Hydrophones
X,G,M Test Vehicle (TV)
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System Components:CPAMS
CPA Measurement Software (CPAMS)Example Plots for Fictional Engagement
Range as a function of timeRange calculated for active transmitsCPA is typically extrapolated valueRange at detonation time based on projection
TPSS-centric 3d plotRange decomposed into (x,y,z) relative to TPSSUseful for visualization of engagement
ATT position relative to TPSS at time of
ATT transmit12
Summary
TPSS development process was streamlined resulting in rapid delivery
Six TPSS units were accepted by the Government 28 months after kickoff meeting
TPSS provides accurate range measurements
TPSS has a total of nearly 100 runs since it was delivered
TPSS has proven to be a reliable system with a 94% in-water success rate
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Acknowledgements
TPSS was funded by the Central Test & Evaluation Investment Program (CTEIP) Resource Enhancement Project (REP)
Endorsements and technical direction provided by Commander Operational Test and Evaluation Force (COMOPTEVFOR)
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