Документ взят из кэша поисковой машины. Адрес оригинального документа : http://zebu.uoregon.edu/~uochep/talks/talks04/ligo11-04.pdf Дата изменения: Mon Feb 7 21:59:05 2005 Дата индексирования: Tue Oct 2 11:09:18 2012 Кодировка: Поисковые слова: чфптбс лпунйюеулбс улптпуфш

Optimal Filtering Suprenovae Event Search : Current Status

Search Code : - LAL based code ( build based on Ringdown Search Code in the LAL/LALAPPS ) - Testing, bug fixing and tuning in progress ( Segment size, highpass frequency, SNR threshold )

Templates : - Require adjustments on the simulated waveforms to use them as templates since none of the waveforms starts and ends with zero amplitude - Smooth beginning using exponential decay, and ending utilizing BИzier curve


Search Code

Templates

Frame Data

z( t ) = 4
Average Noise Power

$

# 0

~ ~ h( f ) s* ( f ) e Sn ( f )

2 "ift

df

Highpass

- Use hanning for average noise power - No windowing for numerator part of the matched filter

Highpass

!
Response Function Truncate Average Noise Power

Matched Filter Output
Search Segment Scan only mid section

FFT Frame

~ s* ( f )
FFT Template

Sn ( f )
Matched Filtering

~ h( f )

Time

! !

!
Check SNR Threshold Single IFO Event ( Start time, Peak time, Duration, SNR, Amplitude )

- Search segment overlapping 50% - Scan events only on the middle part of a search segment since no windowing in the numerator ) - Ignore 1/4 of mached filter output at front and end of a segment


Template Conditioning : An Example

# ! Strain !# !$

)*#!

!$#

Waveform : s11A1000B0.5
- Not all the waveforms starts and end with zero amplitude - Require coditioning to minimize leakage - Apply exponential decay at the beginning, and BИzier curve at the end of the waveform to smooth out !"% Time (sec) !"& !"' !"(

,-./010-.2/*34526-78 94:*34526-78 !"# !"$

!% !
!$$

Spectrum : s11A1000B0.5
94:*34526-78 94:*34526-78*;*<4..0.= ,-./010-.2/*34526-78

#! Strain / sqrt(Hz) #! #! #! #!

!$&

!$(

!$+

!%!

#!

#

#!

$

#! Frequency (Hz)

%

#!

&