4. Calculation of impulse response of hydrophone

%matplotlib inline

from meas_data_preprocessing import *
from hydrophone_data_preprocessing import *
from PyDynamic.uncertainty.propagate_DFT import GUM_iDFT

Load calibration data

meas_scenario = 13
infos, measurement_data = read_data(meas_scenario=meas_scenario)
_, hyd_data = read_calib_data(meas_scenario=meas_scenario, do_plot=False)

Checking if file ../datasets/pD7_MH44.DAT is already present or download it from https://raw.githubusercontent.com/Ma-Weber/Tutorial-Deconvolution/master/MeasuredSignals/pD-Mode%207%20MHz/pD7_MH44.DAT otherwise:
Replace is False and data exists, so doing nothing. Use replace=True to re-download the data.
Checking if file ../datasets/pD7_MH44r.DAT is already present or download it from https://raw.githubusercontent.com/Ma-Weber/Tutorial-Deconvolution/master/MeasuredSignals/pD-Mode%207%20MHz/pD7_MH44r.DAT otherwise:
Replace is False and data exists, so doing nothing. Use replace=True to re-download the data.
Checking if file ../datasets/MW_MH44ReIm.csv is already present or download it from https://raw.githubusercontent.com/Ma-Weber/Tutorial-Deconvolution/master/HydrophoneCalibrationData/MW_MH44ReIm.csv otherwise:
Replace is False and data exists, so doing nothing. Use replace=True to re-download the data.
The file ../datasets/pD7_MH44.DAT was read and it contains 2500 data points.
The time increment is 2e-09 s
Checking if file ../datasets/pD7_MH44.DAT is already present or download it from https://raw.githubusercontent.com/Ma-Weber/Tutorial-Deconvolution/master/MeasuredSignals/pD-Mode%207%20MHz/pD7_MH44.DAT otherwise:
Replace is False and data exists, so doing nothing. Use replace=True to re-download the data.
Checking if file ../datasets/pD7_MH44r.DAT is already present or download it from https://raw.githubusercontent.com/Ma-Weber/Tutorial-Deconvolution/master/MeasuredSignals/pD-Mode%207%20MHz/pD7_MH44r.DAT otherwise:
Replace is False and data exists, so doing nothing. Use replace=True to re-download the data.
Checking if file ../datasets/MW_MH44ReIm.csv is already present or download it from https://raw.githubusercontent.com/Ma-Weber/Tutorial-Deconvolution/master/HydrophoneCalibrationData/MW_MH44ReIm.csv otherwise:
Replace is False and data exists, so doing nothing. Use replace=True to re-download the data.

Align calibration data with measurement data

# reduce frequency range of calibration data
hyd_data = reduce_freq_range(hyd_data, fmin=1e6, fmax=100e6)

measurement_data = uncertainty_from_noisefile(
    infos, measurement_data, do_plot=False, verbose=False
)
measurement_data = calculate_spectrum(measurement_data, do_plot=False)
fmeas = measurement_data["frequency"].round()

hyd_interp = interpolate_hyd(hyd_data, fmeas)

Transform to time domain to calculate impulse response

H_RI = np.r_[hyd_interp["real"], hyd_interp["imag"]]
U_HRI = np.r_[
    np.c_[np.diag(hyd_interp["varreal"]), hyd_interp["cov"]],
    np.c_[hyd_interp["cov"], np.diag(hyd_interp["varimag"])],
]

# application of inverse Fourier transform
imp, Uimp = GUM_iDFT(H_RI, U_HRI)

# centralisation of impulse response
dt = 1 / (hyd_interp["frequency"][1] - hyd_interp["frequency"][0])
c_time = np.linspace(-dt / 2, dt / 2, np.size(imp))
c_imp = np.fft.fftshift(imp)

figure(figsize=(16, 8))
plot(c_time, c_imp)
xlabel("time in s")
ylabel("impulse response in a.u.")
show()