Testing Methodology for Assessing DAQ

1
Testing Methodology for Assessing DAQ

• 1/C Brian Warner
• Project Advisors CAPT Hartnett
• Dr. Gross
• Sponsor G-AND

2
Outline of Talk

• How and why did this project start?
• What is NDRSMP, DAQ, and SINAD?
• My plans and course of action.
• Results and conclusion.

3
Introduction

• What is the importance of NDRSMP?
• Improving communications technology for NDRSMP
  ultimately saves human lives.
• Taking the Search out of Search And Rescue.

4
Background

• NDRSMP contracts General Dynamics 611 million
  dollars. Rescue 21.
• Project split into many categories.
• Direction Finding and DAQ given to USCGA.
• Requirement specification of 3.4 DAQ.

5
TSB-88-A-1

• Table Delivered Audio Quality

6
Objectives

• DAQ subjective ? objective.
• What quality does this sample have?
• Incorporate theory into a software algorithm.
• Present results to NDRSMP.

7
Objectives

• Take an audio sample and load it into an
  algorithm.
• Algorithm assigns a SINAD value to the audio
  sample after fine tuning the sample.
• Take the SINAD value and correlate it to DAQ
  using TSB-88-A-1.

8
Getting Started

• Software is the solution.
• Started work in MATLAB with Moriches.mat I and Q
  data file.
• Moved on to real-life speech segments taken from
  the Academys VHF-DF receiver.
• Then used a microphone and recorded my own voice.

9
SINAD

• Signal Noise Distortion
• Noise Distortion
• Noise is predominant factor degrading analog DAQ.
• Distortion is predominant factor degrading
  digital DAQ.

10
Signal in Time Domain
Magnitude
Samples
11
Absolute Value Filtered
Magnitude
Samples
12
Threshold Values
Magnitude
Samples
13
Noise

• How did I pick those threshold values?
• Adding noise in MATLAB.
• How does adding noise assist in the process?
• Noise 0.0 0.2 0.4

14
Absolute Value of a Different Audio Clip
Magnitude
Samples
15
Absolute Value Filtered Threshold Values
Magnitude
Samples
16
Signal or Noise
Magnitude
Samples
17
Zero Mean Crossings

• Zero crossings occur when neighboring data points
  have different signs.
• 1 0 1 0 1 0 1 0 1 0
• 1 0 0 0 1 0 0 0 1 0

18
Zero Mean Crossings
Magnitude
Samples
19
Eliminate Noise
Magnitude
Samples
20
Conclusions

• What NDRSMP is, why it is important, how my
  project plays a role.
• Algorithm works for voiced speech.
• With an added constant factor the SINAD values
  correlate to DAQ values in TSB-88-A-1in
  accordance with the subjective table.
• Future of the project.