SimChirp.py

#!/usr/bin/env python
"""
Simulates chirp transmission without noise
"""
from numpy import arange
from matplotlib.pyplot import figure, show

#
from tincanradar.fwdmodel import chirptx

bm = 0.3e6  # Hz
tm = 0.1  # s
tfs = 1e6  # Hz #for sim only

t = arange(0, tm, 1 / tfs)

# %% raw chirp waveform centered at IF frequency (here, it's 0)
sig = chirptx(bm, tm, t, nlfm=0.0)
# %% Plot power spectral density (PSD)

# f, t, Sxx = spectrogram(sig, tfs)
# ax.pcolormesh(t, f, Sxx)

fg = figure()
ax = fg.gca()
hi = ax.specgram(sig, Fs=tfs, vmin=-100)[-1]
ax.set_ylabel("Frequency [Hz]")
ax.set_xlabel("Time [sec]")
ax.set_title("Chirp PSD (centered on LO frequency)")
fg.colorbar(hi, ax=ax)


show()