progress in fy 02 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Progress in FY-02 PowerPoint Presentation
Download Presentation
Progress in FY-02

Loading in 2 Seconds...

play fullscreen
1 / 30

Progress in FY-02 - PowerPoint PPT Presentation


  • 180 Views
  • Uploaded on

Research RDA Capability to collect time series data Control of phase shifter Phase coding Sigmet’s implementation of SZ algorithm Ground clutter filtering if P 1 < P 2 Collected sample time series of SZ coded data. Progress in FY-02. Operational in legacy and RRDA mode

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Progress in FY-02' - delila


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
progress in fy 02
Research RDA

Capability to collect time series data

Control of phase shifter

Phase coding

Sigmet’s implementation of SZ algorithm

Ground clutter filtering if P1 < P2

Collected sample time series of SZ coded data

Progress in FY-02

Technical Interchange Meeting

research rda status
Operational in legacy and RRDA mode

Both modes accommodate RVP-7 in parallel

RVP-7 used for JPOL demo

Plan to integrate RVP-8 ASAP

Research RDA Status

Technical Interchange Meeting

rrda status
Full control of radar

Integrated with ORPG

Phase shifter control

Versatile VCP structures and tools

Real-time displays

VCP 43 & 44 implemented, data to ROC

Real-time phase coded acquisition with first trip decoding

RRDA Status

Technical Interchange Meeting

rrda status1
Staggered PRT capability implemented

Working on real-time software for staggered PRT

Continuous archive level 1 and 2 for several hours

Real-time playback of archive data

Data storage in compressed native format

Matlab format and ingest into Matlab

Recording on tape, CD, and/or DVD

RRDA Status

Technical Interchange Meeting

sz decoding algorithms
SZ Decoding Algorithms
  • Analysis of Sigmet’s SZ decoding algorithm
    • Sigmet provided internal notes on decoding algorithm
  • Comparison with NSSL’s SZ-1 decoding algorithm
    • Major difference is in the substitution method
  • MATLAB simulations to compare performance

Technical Interchange Meeting

sigmet s implementation
Sigmet’s Implementation

Technical Interchange Meeting

sz 1 algorithm
SZ-1 algorithm

Technical Interchange Meeting

sd v for the two methods
SD(v) for the two methods

Technical Interchange Meeting

sd v for the two methods1
SD(σv) for the two methods

Technical Interchange Meeting

bias in v for the two methods
Bias in σv for the two methods

Technical Interchange Meeting

gcf and phase coding
GCF and Phase Coding
  • Optimum ground clutter filter
    • Frequency response
    • Notch width
  • Ground clutter filtering if P2 > P1
    • Sigmet reverts to random phase processing
    • SZ algorithm was modified to address this problem

Technical Interchange Meeting

optimum clutter filter

C(v) + N

Input

S(v) + N

Noise level:N

v

GCF(v)

N-1

1

C(v) + N

v

S(v) + N

Output

N

Normalized noise level:1

v

Optimum Clutter Filter

Technical Interchange Meeting

effects of the number of samples
Effects of the number of samples

Technical Interchange Meeting

optimum filter width
Optimum filter width

1.3

Technical Interchange Meeting

clutter filtering if p c p 2 p 1
Clutter filtering if Pc>P2>P1
  • Re-cohere 1st trip and filter ground clutter
  • Restore lost spectral coefficients of 2nd trip replicas
  • Re-cohere 2nd trip, obtain moments, and filter 2nd trip signal
  • Re-cohere 1st trip and obtain moments

Technical Interchange Meeting

restoration of lost 2 nd trip spectrum replica
Restoration of lost 2nd trip spectrum replica
  • Use the remaining replicas to determine the magnitude and phase
    • similar to substitution and works at narrow widths
  • Reconstruction of magnitudes and phases in case there is only one overlap of the spectral replicas
    • extends the range of spectrum widths
    • requires solution of linear equations (overdetermined system)

Technical Interchange Meeting

gcf effect on 2 nd trip spectrum replicas
GCF effect on 2nd trip spectrum replicas

Technical Interchange Meeting

p 2 p 1 ratio for which spectral moments of 1 st trip can be recovered
P2/P1 Ratio for which spectral moments of 1st trip can be recovered

Technical Interchange Meeting

data collection
Data Collection
  • Volume Coverage Pattern Definitions
    • ROC requested non-standard VCPs
    • Modified RRDA VCP definitions to accommodate new requirements
      • Automatic switch between phase-coded and non-phase-coded elevation cuts
      • Staggered PRT
  • Level-1 Data Archiving
    • Expanded data headers to include new metadata
    • Currently support MATLAB and RRDA internal formats

Technical Interchange Meeting

collection of sz coded data
Collection of SZ coded data

Reflectivity field

PRT #1

T = 3.1 ms

ra = 466 km

vNYQ = 8.92 m s-1

Technical Interchange Meeting

collection of sz coded data1
Collection of SZ coded data

Doppler velocity field

PRT #1

T = 3.1 ms

ra = 466 km

vNYQ = 9 m s-1

Technical Interchange Meeting

real time decoding of 1 st trip
Real-time decoding of 1st trip

PRT #4 (T = 1.17 ms)

ra = 175 km

vNYQ = 24 m s-1

PRT #8 (T = 0.78 ms)

ra = 117 km

vNYQ = 35 m s-1

Technical Interchange Meeting

plans
Plans
  • Real-time implementation of SZ algorithm
  • Real-time implementation of Staggered PRT
  • SPS Simulator
  • Oversampling and Whitening in range

Technical Interchange Meeting

sps simulator
SPS Simulator
  • R/V algorithms require development at the RDA DSP level
    • Rapid algorithm prototyping and validation
    • Data visualization tools
    • Off-line development using Archive 1 data
  • Working on simulation of RRDA DSP (Legacy WSR-88D HSP/PSP) using MATLAB
    • Capability to simulate RVP-8

Technical Interchange Meeting

plans for the sps simulator
Plans for the SPS Simulator
  • Data Analysis
    • Spectral analysis
  • Data Processing
    • R/V ambiguitiy mitigation
      • Phase coding
      • Staggered PRT
    • Interaction with other techniques
      • Oversampling and whitening in range

Technical Interchange Meeting

slide27

Oversampling of Weather Echoes in Range

L samples within the pulse

Technical Interchange Meeting

whitening transformation based estimates
Whitening-Transformation-Based Estimates
  • Oversample in range by a factor of L
    • Range samples are correlated
    • Correlation is known assuming uniform reflectivity
  • Decorrelate oversampled range data
    • Whitening transformation is derived from “known” C
    • Works for SNR > 15 dB
  • Compute autocovariances for each range gate
  • Average autocovariances from L range gates
    • Statistical errors are reduced

Technical Interchange Meeting

slide29

Reduction in statistical errors by processing

oversampled signals in range

PRT = 3 ms

M = 32

L = 9

NEXRAD specification

Technical Interchange Meeting

plans for oversampling and whitening in range
Plans for Oversampling and Whitening in Range
  • Collection of oversampled data with RRDA
    • Long pulse, L = 3
    • Digital receiver, L ≥ 5
    • Examine RVP-8 capabilities
  • Statistical analysis
    • Matched filter, Regular averaging, Whitening
  • Visual comparison of PPI displays
  • Effects of reflectivity gradients
  • Pseudo-whitening techniques

Technical Interchange Meeting