IDEA: A methodology paper about issues on source reconstruction
Reading the old version, these are some comments:
- Check the earth coordinates of KAGRA and LIGO/India
Last paper should be Phys. Rew. D 90, 024053 (2014)
- Check if the sensitivity curves have changed
The same paper gives the same curves we are already using (as it seems comparing the figures)
- Remind the contributions of main effects on source estimation:
Triangulation -> Paper puts comparison with 3ifo Wen&Chen formula -> Put results from Feirhust paper?
Antenna pattern -> Puts results using a small earth radius?
- Analysis probably should be re-done with an appropriate cWB svn version and configuration parameters: establish which
- Decide which waveform to use
State of the art
Reed paper presents results for 2015HL and 2016HLV, link at DCC
. This paper should presents results from 3-fold network to 5-fold network, adding analysis using Invariant Topology detectors.
Last results on source reconstruction are in this wiki page
. In particular:
- The comparison of un-modeled search (row 22) with respect to a previous version link shows little difference, some better, other worse, but not so important. Improvements with respect to 1G still remains.
- Some not understood aspects remains, in particular on P search (row 21). This search performs a circular constraint adding a transformation on the pixel composing the cluster. In particular this transformation make a projection of the pixels likelihood according to the mean values of all composing the cluster. For an example see the link under the title "G & MASK". It is not still clear why the circular polarization waveform has worse results while linear polarization ones are better.
I made some simulations of SG for various Q for LHV network. Results report median value of erA over each single sky pixel (Healpix=4) and construct Lars Histogram.
Results show a dependency on frequency according to the sensitivity curve as in the figure:
According to the results, the following comes out:
- For lower frequency (up to 500 Hz) the curves seems following the behaviour of 1/f^2, like in Wen&Chen formula
- For upper frequency, the results are probably related to algorithm approximation, this is quite confirmed by test with upTDF=8 (instead of 4) for SGQ9
- For higher Q, performances worse, because it enters the group error, other than phase error. It would be nice to identify the correlation between the two effects
Consider a methodological paper where studying in details the results explaining the possible causes, like explained in the previous bullets. Some starting point:
- Network: 3-fold and 4-fold, no invariant detectors.
- Waveforms: Focus on SG, linear and elittical polization. Study the results on variation on polarization values. Could be interesting to see RingDown (nearer to astrophysical binaries?)
- Search: R and E (other polarization if there is space.)
- SNR: characterize at fixed network SNR. Consider a study of reduced waveforms varying SNR.
Notes from LVC meeting in Pasadena
Low-latency localization of sources of transient Gravitational Waves with generic waveforms
Assume that a low-latency GW detection is triggering a low latency GW follow-up for estimation purposes
- A. Methodological investigation: understanding and comparing performances simulations vs network SNR
LHV 32Hz-2kHz, ADE design spectral sensitivity, with Gaussian noise
R and P(new) searches
SG as a function of central frequency, Q (3-100), ellipticity
Ring-down, WNB, …
- B. Performances on astrophysical source distributions
Simulations with astrophysical motivated source populations (best if multimessenger prompt follow-up is motivated)
NSBH, BBH uniform in volume
NS excitations, galactic mode
P(new) search LHV, LHV+Kagra ?
- C. Lesson learned for advanced detectors observations