Simulating the detector noise

GWForge (at the moment) can generate a realisation of coloured Gaussian noise from a power spectral density, and it also generates strain data without any noise at all.

For example, here is a noise configuration file for XG detectors:

[IFOS]
detectors = ['CE20', 'CE40', 'ET']
sampling-frequency = 8192
noise = Gaussian
fft-scheme = numpy

Which you can run as follows:

gwforge_noise --gps-start-time 1893024018 --gps-end-time 1893187858 --config-file xg.ini --output-directory data

This will generate roughly a day’s worth of data for an XG detector network at a sampling frequency of 8192Hz. The strain data will be a realisation of coloured Gaussian noise, and the noise power spectrum is read from here:~/.conda/envs/gwforge-test/lib/python3.9/site-packages/GWForge/ifo/noise_curves. The generated strain data will be stored as *.gwf in the output directory with names {IFO}-{GPS-TIME}.gwf with channel names {IFO}:INJ.

Here is a short-cut in case you forget:

FrChannels <frame-file>

will list all the channels in the frame files and

FrCheck -i <frame-file>

Will list the gps start and end time of the frame file.

Alternatively, you can define the configuration file as follows:

[IFOS]
detectors = ['CE20', 'CE40', 'ET']
sampling-frequency = 8192
noise = Gaussian
fft-scheme = numpy
gps-start-time = 1893024018
duration = 86400

And remove the gps option.

Note

By default, gwforge_noise will use pycbc.noise.reproducable to generate the strain data. You can use Bilby’s method by defining noise-type=bilby.

Warning

If you are interested in generating strain data without any noise, please define noise-type=bilby.

Warning

If you have MKL properly configured or you want to use CUDA for FFT you can pass fft-scheme=mkl or fft-scheme=cuda. It should work, but no promises.

Finally, you can define your configuration file as follows:

[IFOS]
detectors = ['H1', 'L1', 'V1']
psd-dict = {'H1' : 'H1.txt', 'L1': 'L1.txt', 'V1':'V1.txt'}
sampling-frequency = 8192
noise = Gaussian
fft-scheme = numpy
gps-start-time = 1893024018
duration = 86400

by providing a Dictionary of PSD files to use.